Pre-sowing treatments are expected to increase seed germination.This evaluates response to pre-sowing treatments and the growth performance of two native and rare tree species,Garuga pinnata Roxb.and Vitex glabrata R....Pre-sowing treatments are expected to increase seed germination.This evaluates response to pre-sowing treatments and the growth performance of two native and rare tree species,Garuga pinnata Roxb.and Vitex glabrata R.Br.The hard seed coats were treated by rubbing with sand paper,nail clipping,and immersion in water and acid（H_2SO_4）.Results indicate that G.pinnata showed a 90% germination rate and 30% germination energy when seed coats were nicked with a nail clipper.Rubbing with sand paper was the best pre-sowing treatment for V.glabrata,resulting a 80% germination rate and 30% germination energy.G.pinnata and V.glabrata seedlings from seeds soaked 24h in water resulted in maximum heights and collar diameters.These were significantly higher（at p〈0.05） than those of other treatments.The results indicate that scarification or nicking of seeds may have some negative impacts on seedling growth.Therefore,it is difficult to recommend a pre-sowing treatment of seeds for achieving both maximum germination and good early seedling growth.展开更多
Thorn scrub vegetation in Mexico is distributed over 50 million ha, where native tree species are the source of forage, timber, firewood and charcoal. Research describing wood durability of species from this vegetatio...Thorn scrub vegetation in Mexico is distributed over 50 million ha, where native tree species are the source of forage, timber, firewood and charcoal. Research describing wood durability of species from this vegetation type has not been fully determined, nor classified according to international standards. Thus, the aim of this study was to determine and classify the natural durability of ten woody species. Their natural durability was determined according to the European Pre-Norm 807, the loss of dynamic modulus of elasticity （MOEdyo） （MPa） was determined and wood mass loss （g） after being exposed to Trametes versicolor and Coniophora puteana fungi. Wood durability was classified accord- ing to the European Norm 350-1. Highly significant differences （p 〈 0.001） were found between the durability of woody species. The more durable species with lower MOEdyn lost were Condalia hooked （57.5% ± 0.6%）, Havardia pallens （58.2% ± 0.4%） and Acacia schaffneri （58.9% ±6.3%）. Species with lower mass loss after exposed to Coniophora puteana were Ebenopsis ebano （6.3% ±1.9%）, Condalia hooked （8.6% ±2.3%） and Cordia boissieri （11.8% ±2.3%）. E. ebano （7.1% ±2.4%）, Condalia hooked （8.2% ± 2.5%） and Cordia boissieri （11.5% ± 3.1%） showed the lower mass lost after exposed to T. versicolor. According to European Norm 350-1, three woody species were classified as very durable and durable species.展开更多
Exotic tree species,though widely used in forestry and restoration projects,pose great threats to local ecosystems.They need to be replaced with native species from natural forests.We hypothesized that natural forests...Exotic tree species,though widely used in forestry and restoration projects,pose great threats to local ecosystems.They need to be replaced with native species from natural forests.We hypothesized that natural forests contain large,fast-growing,dominant native tree species that are suitable for specific topographic conditions in forestry.We tested this hypothesis using data from a 50-ha forest dynamics plot in subtropical China.We classified the plot into the ridge,slope,and valley habitats and found that 34/87 species had significant associations with at least one topographic habitat.There were 90 tree species with a maximum diameter≥30 cm,and their abundances varied widely in all habitat types.In all habitat types,for most species,rate of biomass gain due to recruitment was<1%of its original biomass,and rate of biomass gain due to tree growth was between 1 and 5%of its original biomass.For most species,biomass loss due to tree mortality was not significantly different than biomass gain due to recruitment,but the resulting net biomass increment rates did not significantly differ from zero.The time required to reach a diameter of 30 cm from 1 cm diameter for Altingia chinensis in the slope habitat,for Quercus chungii and Morella rubra in the ridge habitat and for Castanopsis carlesii in all habitats could be as short as 30 years in our simulations based on actual distributions of tree growth observed in the forest.Principal component analyses of maximum diameter,abundance and net biomass increment rates suggested several species were worthy of further tests for use in forestry.Our study provides an example for screening native tree species from natural forests for forestry.Because native tree species are better for local ecosystems,our study will also contribute to biodiversity conservation in plantations.展开更多
<i><span style="font-family:"">Cycas angulata, Cycas armstrongii </span></i><span style="font-family:"">and<i> Cycas conferta </i>that are<i&g...<i><span style="font-family:"">Cycas angulata, Cycas armstrongii </span></i><span style="font-family:"">and<i> Cycas conferta </i>that are<i> </i>native species of Australia were collected in Darwin city of tropical region, <i>Zamia </i><i>erosa </i>and angiosperm <i>Guaiacum officinale</i> of Zygophyllaceae which are introduced collected in the Darwin Botanic Gardens, and were carried out light microscope and electron microscope observed research to tracheary element and parenchyma tissue cells of leaflet, rachis and stem. The results showed that there are more vessel elements in their xylems;the length of vessel element of Cycadaceae with Zamiaceae are not obvious difference, the length of vessel element of angiosperm <i>Guaiacum officinale</i> is shorter, but their diameter is smaller, we thought that the characteristics which the length of vessel element is longer and the diameter is bigger are more evolutionary, because thus vessel, their number which interconnected points of possessed perforations’ end walls of vessel element is fewer, and the passageway space is larger so that the conduction speed and quantity are faster and more in unit length range and unit time. These vessels are annular vessels, spiral vessels, scalariform vessels, reticular vessels, pitted vessels and scalariform-pitted vessels, etc. In the transverse section, the vessel elements of Cycadaceae and Zamiaceae are circular, polygonous, more similar to vessel characteristics of <a name="OLE_LINK73"></a>leaf and stem of some angiosperms;however, the number of circular vessel of <a name="OLE_LINK21"></a><i>Guaiacum </i><i>officinale</i> is more, about occupy 35%, others are polygonous. The diameter of vessel is that annular vessel, spiral vessel is least, scalariform vessel or scalariform-reticular vessel is medium, reticular vessel and pitted vessel are the biggest, the characteristic is same as angiosperm. In <i>Cycas conferta</i>, etc. plants often can see several large perforations in the end walls, some species are several big scalariform or pitted perforations formed multiple perforation plates, in many vessel element lateral walls, there are some perforations formed a horizontal transport avenue of aqueous solution. The scale of diameter of <i>Cycas</i> vessel element is similar to that of <i>Zamia</i>, but the diameter of more vessel elements of <i>Cycas angulata </i>and<i> Cycas conferta</i> is bigger than the latter, and is bigger than that of <i>Guaiacum officinale</i>, although <i>Cycas</i> plants are more primitive than <i>Zamia</i><i> </i>plants, and <i>Guaiacum officinale</i> is more evolutionary, but the scale of vessel diameter of <i>Cycas</i> plants is similar to <i>Zamia </i>or bigger than the latter, even larger than <i>Guaiacum officinale</i>, these showed that cycads have evolutionary and more developed characteristics in aqueous solution transport system. In <i>Guaiacum officinale</i>, more vessel element has been not seen the ridges in the different directions of side walls which can make vessel has more mechanical supportability, but some possessed the ridges;however, more vessel elements are twist shape and can twist together each other, thus the state can increase their mechanical supportability, and their synergy with fiber elements which is longer with a twist shape, therefore their capability of xylem conduction and the combine mechanical support capability with mechanical tissue are also stronger. In the respect of observed parenchyma tissue, any parenchyma tissue cells are without perforation, all cell walls are smoothed and like a membrane. Aimed at only one or two people pointed the query about Jeffery’s method, some scholars have made comparative researches, their research used as following methods: 1) The fresh materials were cut sections 1 - 2 mm thick by hand (the query person provided and thought right method), were examined with SEM. 2) The materials were treated by Jeffrey’s Fluid and observed with SEM and so on. The results showed that the pit membrane, the remnants in the perforation and the structural characteristics of perforations were not different;and the results of our comparative research in past time and this research all justified that Jeffrey’s method is reliable and reasonable. Meanwhile, our research results showed that only vessel element can form perforation, in other all parenchyma tissue cells cannot form perforation are also proved that the perforations of vessel element are naturally inherited character. Analyzed from the structural characteristics, although they distributed so far apart from each other, they are a well and unified taxonomy system;we thought that Australia’ most species or all species of Cycadaceae came from Asia, and it is impossible from Africa, because the latter only has one more evolutionary species and lack of fossil of Cycadaceae, these species of Cycadaceae are the descendants of ancestor species;America possessed more genera of Zamiaceae, this family is mutual with Africa and Australia, we thought that these genera of Zamiaceae in Australia and America came from Pangea before continental drift in Jurassic Period, this family is also maybe one of the proofs to Australia drifted from Pangea to present position after Jurassic Period. The characteristics of tracheary element of several different genera of cycads and angiosperm further showed that more primary species or taxon, their more tissue characteristics are not also more primary, because of the need to adapt the environment, they are also constantly evolving. The research is important significant and theory reference to understand cycads evolutionary aqueous solution transport system, and understand the ecological adaptation mechanism which why present cycads of 3 families in world major distributed in tropical or subtropical regions, even many drought and barren areas.展开更多
Active restoration is a critical component of biodiversity conservation for degraded tropical forest ecosystems caused by artisanal gold mining, and the success of restoration is dependent on native species selection....Active restoration is a critical component of biodiversity conservation for degraded tropical forest ecosystems caused by artisanal gold mining, and the success of restoration is dependent on native species selection. However, significant knowledge gaps exist regarding when and where to plant trees. This article reports on a revegetation trial undertaken in St Elizabeth, Mahdia, Guyana, to assess the survival and RGR (Relative Growth Rate) of three native woody trees and shrubs planted within three years old Acacia mangium Willd trees pruned and unpruned blocks. ANOVA (Analysis of Variance) for a completely randomized block design with four blocks, two pruned and two unpruned, within A. mangium plots. Biochar treatment was added to the plants during transplanting. Thirty-six (36) wildlings of Humiria balsamifera (Aublet.) (Tauroniro), Goupia glabra Aublet (Kabukalli), and Vismia guianensis (Aublet.) Choisy (Bloodwood) were collected and raised in a tree nursery for two weeks. The native plants were transplanted 3 m apart, survival observations and each seedling’s initial height and diameter were measured and recorded. After the experiment, 13% of seedlings from a population of 720 had died, with the highest mortality being experienced at the 92 days of the experiment (t ≤ 122 days). While the overall survival rates were high, emphasizing the importance of field trials on native and exotic species in different environments is essential to fill the knowledge gaps on suitable species for restoration in degraded areas with other land use histories.展开更多
Both abiotic conditions and management influence the success of forest restoration.Despite growing interest and practical effort in restoring degraded forest landscapes,understanding of how disparate factors,such as t...Both abiotic conditions and management influence the success of forest restoration.Despite growing interest and practical effort in restoring degraded forest landscapes,understanding of how disparate factors,such as terrain,soil conditions,climate and silvicultural treatments,directly or collectively control species performance and shape community recovery remains limited.In this study,we assessed how topography and management intervention affect seedling survival and growth in the early stages of restoration.To do so,we established seven experimental plots,each measuring 20 m×20 m(400 m2)subdivided into 48 subplots,in coarse,anthropogenic grassland on a mid-elevation mountain slope in Hong Kong,and planted a total of 3975 native tree seedlings belonging to 12 tree species within them.To characterise topography,we modelled the elevation,slope,convexity and aspect of each subplot.Two types of tree guard(enclosed blue plastic sleeve and open yellow mesh),two types of fertiliser(organic and inorganic)and cardboard weeding mats were used to assess the impact of management interventions on the establishment of the seedlings.Survivorship,height and basal diameter were measured at 1,2 and 4 years after planting.We used generalised linear models to examine the effect of these factors and their interactions on seedling survival,and we applied linear models and hierarchical partitioning to explore their relative importance in determining the relative growth rate(RGR)of each species.The most parsimonious models were selected using the Akaike Information Criterion.Survivorship was 98.1%,95.2%and 86.4%across all plots in the first,second and fourth year,respectively.On average,topographic and management variables explained 1.48–3.34%of total variation in RGR,respectively,for all species.The models revealed that type of tree guard,aspect and elevation were the most important factors explaining RGR and survival.Results of hierarchical partitioning by species and growth period showed that the key determinants of performance vary by species and shift over the course of early seedling establishment,emphasising the importance of both spatial and temporal scales in the restoration of degraded tropical forests.Our findings support the use of enclosed tree guards and fertiliser to improve survivorship and growth across a range of broadleaved Asiatic species.All potential limiting factors pertaining to both site factors and management,as well as their interactions,should be considered in restoration planning to maximise restoration success.展开更多
The relationship between soil properties and spatial distribution of native woody species was studied in three Taita Hills forest fragments which, although degraded, are ranked among 34 biodiversity hotspots of the wo...The relationship between soil properties and spatial distribution of native woody species was studied in three Taita Hills forest fragments which, although degraded, are ranked among 34 biodiversity hotspots of the world due to their high biodiversity of both plant and animal species. This relationship was assessed by using Spearman correlation and principal component analyses （PCA）. The results of these analyses should be useful in instituting forest restoration programs that are crucial for the forests. Both the soil and vegetation studied were sampled from 17 subplots in the natural forest fragments of Ngangao （120 ha）, Chawia （86 ha） and Mbololo （185 ha）. The soil variables measured were： pH, texture, soil nutrients of C, N, Ca, P, K, Mg and Na. In total 36 native tree species from 13 families were identified from the three forest fragments. Ordination results show that axis 1 accounted for 35% and axis 2 for 25% of the total variation in species composition, indicating that the structure of vegetation is related to two major environmental gradients. The correlation analyses of species and soil properties showed that Na and clay particles were the most important determinants of species distribution; pH and soil variables such as C, N, Ca and P also played minor roles. Unexpectedly, some species （e.g. Psychotria petitii） showed positive relationships with Na attributed to possible substitution for K. Relationships with P were both positive （e.g. Craibia zimmermannii） and negative （e.g. Albizia gummifera） with some species, attributable to pH levels. An ANOVA for soil variables showed that there were differences in the Ca content in Mbololo （due to the parent material） and P in Ngangao where a special relationship was observed between some of the species. The presence of gaps accounted for the distribution of seedlings but not for the saplings, whose distribution responded more to factors similar to those to which mature trees respond. Soil-species relationships that were established may be utilized along with soil analyses when choosing native species for restoration.展开更多
Forests over limestone in the tropics have received little attention and limestone forests in Vietnam have been overlooked to an even greater extent in terms of tree physiology. In Ba Be National Park, Vietnam, soil w...Forests over limestone in the tropics have received little attention and limestone forests in Vietnam have been overlooked to an even greater extent in terms of tree physiology. In Ba Be National Park, Vietnam, soil water availability in limestone forests seems to be the most limiting factor in the dry season. Therefore, in order to enhance the preliminary knowledge of choosing native tree species for enrichment planting in the restoration zone, characteristics of the 20 native tree species to soil water stress were investigated in a limestone forest. One-ha plot each consisting of twenty-five 20 m × 20 m plots was established in undisturbed forests. All trees ≥ 10 cm DBH were measured in 20 m × 20 m plots, while twenty-five 5 m × 5 m subplots were established in order to sample the regeneration of tree species with a DBH < 10 cm. The Scholander apparatus and freezing point osmometry were used in order to measure the leaf water potential (Ψw) and leaf osmotic potential (Ψπ) of the 20 native tree species, respectively in this study. 61 species belonging to 34 families of all trees with a DBH ≥ 10 cm were recorded in one ha, while 31 species representing 18 families of trees < 10 cm DBH were identified in 625 m2. The 20 species’ leaf water and osmotic potential values revealed significant differences among species. The maximum leaf water potential was not affected by any anticipated sources of variation, while the minimum water potential, however, showed significant variation to soil water stress. The results in the study area emphasized the importance of water factors in influencing tree species distribution;it could be concluded that native species with wide water potential ranges would be better able to withstand water changes and might be thus good candidates for reforestation (enrichment planting) in limestone areas.展开更多
Propagation of exotic plant species is found in many regions of Madagascar Island. This work aims to describe the impacts of the propagation of Grevillea banksii on soil microbial activities and on the regeneration of...Propagation of exotic plant species is found in many regions of Madagascar Island. This work aims to describe the impacts of the propagation of Grevillea banksii on soil microbial activities and on the regeneration of two native tree species （Intsia bij＇uga and Dalbergia trichocarpa） in the eastern part of Madagascar. The study was conducted within Ianjomara forest where some types of the vegetation are observed such as an area characterized by grassland （P 1）, by homogeneous population of G. banksii （P2） and by a natural forest composed mainly of L bijuga or D. trichocarpa （P3 and P4）. Structure of mycorrhizal fungi communities and associated microorganisms were described on soils from each study plot. The development of I. b^juga and 1）. trichocarpa, was evaluated 4 months after planting on P1, P2, P3, P4 soils formerly colonized by G. banksii. According to the nutrients availability on each soil type, the development of G. banksii was accompanied or not by a high formation of cluster roots. The authors＇ results also show that soil occupied by G. banksii decreased the global microbial and phosphatase activities of soil especially on soil within a high density of cluster roots. Moderately mycotrophic, G. banksii disturbs the structure and the dynamics of symbiotic microflora such as endomycorrhizal fungi （MA） and rhizobia associated with the two native tree species. The findings illustrate the negative impact of G. banksii propagation on the regeneration and the conservation of native tree species in Madagascarian forest.展开更多
Native tree species play a very important role in the planning and design of urban green landscape. It has strong adaptability to the local natural environment, beautiful landscape, convenient management, and has the ...Native tree species play a very important role in the planning and design of urban green landscape. It has strong adaptability to the local natural environment, beautiful landscape, convenient management, and has the cultural connotation of the city. It fully reflects the morphological characteristics of the local native plant landscaping, and is of great significance to the establishment of an ecological city. Based on the investigation of the application of native tree species in the urban green space of Huaian City, Jiangsu Province, the author analyzed the advantages and disadvantages of native tree species planting, and provided some practical planning, design and planting suggestions for good planting and management of native tree species in the urban green space scenic spots of Huaian City, which can be used as a reference for the urban landscape planning and design departments and nursery stock production departments of cities and counties in Huaian City.展开更多
Invasive plant species are exerting a serious threat to biological diversity in many regions of the world. To understand plant invasions this study aims to test which of the two plant invasiveness hypotheses; ‘low na...Invasive plant species are exerting a serious threat to biological diversity in many regions of the world. To understand plant invasions this study aims to test which of the two plant invasiveness hypotheses; ‘low native diversity' vs. ‘high native diversity', is supported by the regional distribution patterns of invasive plant species in the Himalayas,Nepal. This study is based on data retrieved from published literatures and herbarium specimens. The relationship between invasive plant species distribution patterns and that of native plant species is elucidated by scatter plots, as well as by generalized linear models. The native plant species and invasive plant species have similar distribution patterns and the maximum number of invasive plant species is found in the same altitudinal range where the highest richness for native tree species is found. There is a clear trend of higher invasive plant richness in regions where native tree species richness is relatively high.Consequently, the native plant richness is highest in the central phytogeographic region, followed by the eastern and the western regions, respectively. The invasive plant species also follows a similar trend.Additionally, the invasive plant species richness was positively correlated with anthropogenic factors such as human population density and the number of visiting tourists. This study supports the hypothesis that ‘high native diversity' supports or facilitates invasive plant species. Further, it indicates that nativeand invasive plant species may require similar natural conditions, but that the invasive plant species seem more dependent and influenced by anthropogenic disturbance factors.展开更多
Invasive alien plant species have threatened the integrity of ecosystems and threatened biological integrity throughout the world. In the Nyika National Park, a number of alien invasive plant species have been reporte...Invasive alien plant species have threatened the integrity of ecosystems and threatened biological integrity throughout the world. In the Nyika National Park, a number of alien invasive plant species have been reported. These invasive alien plants are reported to be very difficult that have caused adverse ecological, economic and social impact. The main objective of this study is to assess the environmental impact of plant invasive alien species in Nyika National Park in order to ascertain means of addressing the possible effects on the biodiversity. This study adopted an exploratory stance in order to answer <span>the hypotheses where purposive and simple random sampling was used. P</span>ur<span>posive sampling was only used to the staff of Nyika while simple random s</span>ampling was used to collect data from households surrounding Nyika National Park. The results revealed that invasive alien plant species have some ecological impacts of on the biodiversity of the Nyika National Park like change in physical habitats such as loss of native habitats, alteration of ground water regime, drying of rivers, loss of native species and alteration of biomass. The study would therefore be important to policy makers in guiding and devel<span>opment of policies and guidelines governing eradication of invasive alien pl</span>ant species. The Department of National Parks and Wildlife (DNPW) can form partnership with various stakeholders with a clearly stated intention of developing a relationship, based on collaboration to enhance the control of invading alien plant species and the best management practices.展开更多
Reforestation and reforestation efforts are generally dependent on the species recommended by the government. In the Philippines, most reforestation activities use Gmelina arborea, Acacia mangium, and Swietenia macrop...Reforestation and reforestation efforts are generally dependent on the species recommended by the government. In the Philippines, most reforestation activities use Gmelina arborea, Acacia mangium, and Swietenia macrophylla due to their usual economic returns. Thus, the use of native species is less favored over exotic species. This paper considered the species preferences of the local community as involved in reforestation activities in Zambales. Assessment of the stakeholders’ preferences was based on a listing of species given by the respondents and community perceived benefits or uses. Familiarity of the respondents with the species presented to them was also considered in the analysis.展开更多
Farmers are eager to know the various types of weeds in paddy fields.This will help in choosing the best weed management practice for effective weed control as well as reducing rice yield losses.The objectives of the ...Farmers are eager to know the various types of weeds in paddy fields.This will help in choosing the best weed management practice for effective weed control as well as reducing rice yield losses.The objectives of the study are to identify the weeds species affecting the rice field,to assess the composition of weeds species,to classify the weed species into different families,genera,species,common names,Hausa names,lifecycles,life forms,native/exotic species,propagation and uses,and to determine the dominant weed species.Random vegetation surveys were conducted.Weeds observed were photographed,and prepared as herbarium specimens.Standard key manuals and checklists were utilized for weed identification and later organized using the Angiosperm Phylogeny Group(APG)classification system.A total number of 72 plants species distributed within 16 families and 50 genera were inventoried.The annuals(66.67%)were the dominant weed followed by perennials(33.33%)while biennials were the least.The broad leaves were the dominant weed(44.61%)identified followed by Poaceae(27.7%)and Sedges(11.11%).Results obtained from this study could be useful in choosing the best management practice and in making a decision on the choice of herbicides and directing research towards improved weed control measures.展开更多
Hancornia speciosa‘Gomes’,commonly known as mangabeira,is a fruit-bearing tree native to Brazil that plays a crucial role in sustaining its native biome,restoring degraded areas,and improving the socio-environmental...Hancornia speciosa‘Gomes’,commonly known as mangabeira,is a fruit-bearing tree native to Brazil that plays a crucial role in sustaining its native biome,restoring degraded areas,and improving the socio-environmental conditions of these regions.The use of colored materials and bioinputs can help improve the quality of seedling production of Hancornia speciosa.This study aimed to evaluate the use of colored seedling tubes and a Chlorella vulgaris-based bioinput in developing Hancornia speciosa seedlings.The experiment was conducted at the Mato Grosso do Sul State University(UEMS),in Cassilândia,MS,using a completely randomized design in a 5×2 factorial arrangement.Treatments included colored reflective tubes(blue,white,red,yellow,and black)and bioinput application(absence or presence).The Hancornia speciosa seeds were collected near the Cassilândia campus and the Chlorella vulgaris-based bioinput was produced at the Microalgae and Biotechnology Laboratory of the Centro de Desenvolvimento Sustentável do Bolsão Sul-Mato-Grossense(CEDESU).The bioinput was applied at sowing and after 30,60 and 90 days after emergence(DAE),totalizing three applications.An increase in plant height,number of leaves,chlorophyll a and total,CO_(2) assimilation rate,water use efficiency was observed.The combination of tube color and the presence of the Chlorella vulgaris bioinput significantly improved biometric traits,seedling quality index,chlorophyll a and total chlorophyll content,and CO_(2) concentration,thus enhancing the seedling quality and potentially increasing field establishment and survival rates.展开更多
[Objective] The aim was to study pollen morphology of Pennisetum native species.[Method] We carried out the observation by optical microscope and scanning electron microscope on six materials of pollen grains includin...[Objective] The aim was to study pollen morphology of Pennisetum native species.[Method] We carried out the observation by optical microscope and scanning electron microscope on six materials of pollen grains including three species and three transmogrifications from one variant of Pennisetum native species.[Result] The pollen grains were globose or subglobose.Germination aperture which located at distal side was singular and its circumambience was thickened.Pollen wall which had two layers was thin and easy to be crimpled.There were obvious differences between ektexine ornamentations as well as particle sizes.[Conclusion] The question of low seed-setting rate of Pennisetum native species had relations with the withered pollen morphology to some extent.The differences between pollen morphology as well as ektexine ornamentations accorded with the division of species and variants from Pennisetum.In addition,the relationship between pollen morphology and seed-setting rate provided references to introduce good grass seed and choose breeding parent materials of Pennisetum.展开更多
Urban plants provide various ecosystem services and biodiversity for human well-being. It is necessary to examine the plant species and functional traits composition and the influencing factors. In this study, a field...Urban plants provide various ecosystem services and biodiversity for human well-being. It is necessary to examine the plant species and functional traits composition and the influencing factors. In this study, a field survey was conducted using the tessellation-randomized plot method to assess the plant species and functional traits variability in greenspaces across eight land use types(LUTs) in the built-up areas of Beijing, China. Results showed that the woody plants in the built-up areas of Beijing comprised 85 non-native species(57%), 21 pollen-allergenic species(14%), and 99 resistant species(67%). Residential areas, community parks and institutional areas had higher woody plant species richness than other LUTs. Native and extralimital native species were more widespread than exotic species. Proportions of species with resistances were low except for cold-and drought-resistance; consequently, a high intensity of management and maintenance is essential for survival of plants in this urban area. Caution should be exerted in selecting plant species with resistance to harsh conditions in different LUTs. Housing prices, distances from the urban center, years since the establishment of LUTs and greening rate were strongly correlated with the plant functional traits and species diversity. Urban forest managers should consider plant functional traits and LUT-specific strategies to maximize both forest and human health.展开更多
Background:So far,macroecological studies in the Himalaya have mostly concentrated on spatial variation of overall species richness along the elevational gradient.Very few studies have attempted to document the difere...Background:So far,macroecological studies in the Himalaya have mostly concentrated on spatial variation of overall species richness along the elevational gradient.Very few studies have attempted to document the diference in elevational richness patterns of native and exotic species.In this study,this knowledge gap is addressed by integrating data on phylogeny and elevational distribution of species to identify the variation in species richness,phylogenetic diversity and phylogenetic structure of exotic and native plant species along an elevational gradient in the Himalaya.Results:Species distribution patterns for exotic and native species difered;exotics tended to show maximum species richness at low elevations while natives tended to predominate at mid-elevations.Native species assemblages showed higher phylogenetic diversity than the exotic species assemblages over the entire elevational gradient in the Himalaya.In terms of phylogenetic structure,exotic species assemblages showed majorly phylogenetic clustering while native species assemblages were characterized by phylogenetic overdispersion over the entire gradient.Conclusions:The fndings of this study indicate that areas with high native species richness and phylogenetic diversity are less receptive to exotic species and vice versa in the Himalaya.Species assemblages with high native phylogenetic overdispersion are less receptive to exotic species than the phylogenetically clustered assemblages.Diferent ecological processes(ecological fltering in case of exotics and resource and niche competition in case of natives)may govern the distribution of exotic and native species along the elevational gradient in the Himalaya.展开更多
Investment in silvicultural techniques is noticeably lacking,especially in breeding programs for non-conventional wood species.Studying genotype×environment interaction(G×E)is essential to the development of...Investment in silvicultural techniques is noticeably lacking,especially in breeding programs for non-conventional wood species.Studying genotype×environment interaction(G×E)is essential to the development of breeding programs.Thus,this study aimed to estimate genetic diversity of and the effects of G×E interaction on two progeny tests of Cordia trichotoma,including the estimation of genetic gain and genetic diversity after selection.For the experiment,30 progenies of C.trichotoma were tested at two sites with differing soil textures.Diameter at breast height(1.30 m above soil surface,dbh-cm),total height,diameter at 30 cm from the soil,first branch height,and survival were all monitored for four years.Statistical deviance,best linear unbiased estimator,and harmonic mean of relative performance of genetic values(MHPRVG)were all calculated to predict breeding values,estimate genetic parameters,and analyze deviance.All quantified traits varied significantly among progenies by soil type,with greatest variation recorded for genetic variability.Heritability of the progenies led to predictions of genetic gain,ranging from 7.73 to 15.45%,for dbh at four years of age.The calculated decrease in genetic diversity after selection showed that this parameter should be monitored in subsequent breeding cycles.G×E was low for all tests.The best-performing progenies proved most stable and best adapted to the different environmental conditions tested.展开更多
Aims understanding relationships between the distributions of species and their surrounding environment provides a basis for forecasting how species will respond to future environmental changes.In this study,we examin...Aims understanding relationships between the distributions of species and their surrounding environment provides a basis for forecasting how species will respond to future environmental changes.In this study,we examined the effects of environmental factors and human devel-opmental features associated with disturbances on probability of occurrence of juveniles of invasive Triadica sebifera and three native plant species,Baccharis halimifolia,Ilex vomitoria and Morella cer-ifera within a typical coastal transition in coastal mississippi,USA.Methods We recorded presence of juveniles of focal species and measured environmental factors(soil salinity,canopy openness,soil texture and soil carbon to nitrogen ratio)along an 11.3 km transect located at grand bay National Estuarine research reserve.Further,we doc-umented anthropogenic features and associated activities as a proxy for human disturbance.Important Findings With the exception of I.vomitoria,all other species occurrences were significantly influenced by an interaction between soil salinity and canopy openness.The occurrence of I.vomitoria sharply decreased with salinity.B.halimifolia occurrence peaked at moderate levels of salinity and low to moderate levels of canopy openness.occurrences of M.cerifera and the invasive T.sebifera were highest at low levels of salinity and canopy openness.These results indicate that salinity is a strong driver that limits distribution of juvenile native and invasive species in coastal transitions.logistic regression confirmed the positive effects of anthropogenic disturbances on T.sebifera and I.vomitoria occurrence.It appears that while soil salinity is likely to drive retreat of the seaward boundaries of woody plant species distributions,increased human developments along the coast likely enhance the inland spread of species,in particular the invasive T.sebifera by increasing distur-bances and facilitating dispersal.results from this study can offer insight for the development of T.sebifera management and preventive meas-ures for further spread along coastal areas of the southeastern USA.展开更多
文摘Pre-sowing treatments are expected to increase seed germination.This evaluates response to pre-sowing treatments and the growth performance of two native and rare tree species,Garuga pinnata Roxb.and Vitex glabrata R.Br.The hard seed coats were treated by rubbing with sand paper,nail clipping,and immersion in water and acid（H_2SO_4）.Results indicate that G.pinnata showed a 90% germination rate and 30% germination energy when seed coats were nicked with a nail clipper.Rubbing with sand paper was the best pre-sowing treatment for V.glabrata,resulting a 80% germination rate and 30% germination energy.G.pinnata and V.glabrata seedlings from seeds soaked 24h in water resulted in maximum heights and collar diameters.These were significantly higher（at p〈0.05） than those of other treatments.The results indicate that scarification or nicking of seeds may have some negative impacts on seedling growth.Therefore,it is difficult to recommend a pre-sowing treatment of seeds for achieving both maximum germination and good early seedling growth.
基金supported by the Professors improvement Program (PROMEP) and the Science and Technology Support Research Program (Granted to the first author PAICyT)
文摘Thorn scrub vegetation in Mexico is distributed over 50 million ha, where native tree species are the source of forage, timber, firewood and charcoal. Research describing wood durability of species from this vegetation type has not been fully determined, nor classified according to international standards. Thus, the aim of this study was to determine and classify the natural durability of ten woody species. Their natural durability was determined according to the European Pre-Norm 807, the loss of dynamic modulus of elasticity （MOEdyo） （MPa） was determined and wood mass loss （g） after being exposed to Trametes versicolor and Coniophora puteana fungi. Wood durability was classified accord- ing to the European Norm 350-1. Highly significant differences （p 〈 0.001） were found between the durability of woody species. The more durable species with lower MOEdyn lost were Condalia hooked （57.5% ± 0.6%）, Havardia pallens （58.2% ± 0.4%） and Acacia schaffneri （58.9% ±6.3%）. Species with lower mass loss after exposed to Coniophora puteana were Ebenopsis ebano （6.3% ±1.9%）, Condalia hooked （8.6% ±2.3%） and Cordia boissieri （11.8% ±2.3%）. E. ebano （7.1% ±2.4%）, Condalia hooked （8.2% ± 2.5%） and Cordia boissieri （11.5% ± 3.1%） showed the lower mass lost after exposed to T. versicolor. According to European Norm 350-1, three woody species were classified as very durable and durable species.
基金supported by the National Natural Science Foundation of China(31925027,31300455).
文摘Exotic tree species,though widely used in forestry and restoration projects,pose great threats to local ecosystems.They need to be replaced with native species from natural forests.We hypothesized that natural forests contain large,fast-growing,dominant native tree species that are suitable for specific topographic conditions in forestry.We tested this hypothesis using data from a 50-ha forest dynamics plot in subtropical China.We classified the plot into the ridge,slope,and valley habitats and found that 34/87 species had significant associations with at least one topographic habitat.There were 90 tree species with a maximum diameter≥30 cm,and their abundances varied widely in all habitat types.In all habitat types,for most species,rate of biomass gain due to recruitment was<1%of its original biomass,and rate of biomass gain due to tree growth was between 1 and 5%of its original biomass.For most species,biomass loss due to tree mortality was not significantly different than biomass gain due to recruitment,but the resulting net biomass increment rates did not significantly differ from zero.The time required to reach a diameter of 30 cm from 1 cm diameter for Altingia chinensis in the slope habitat,for Quercus chungii and Morella rubra in the ridge habitat and for Castanopsis carlesii in all habitats could be as short as 30 years in our simulations based on actual distributions of tree growth observed in the forest.Principal component analyses of maximum diameter,abundance and net biomass increment rates suggested several species were worthy of further tests for use in forestry.Our study provides an example for screening native tree species from natural forests for forestry.Because native tree species are better for local ecosystems,our study will also contribute to biodiversity conservation in plantations.
文摘<i><span style="font-family:"">Cycas angulata, Cycas armstrongii </span></i><span style="font-family:"">and<i> Cycas conferta </i>that are<i> </i>native species of Australia were collected in Darwin city of tropical region, <i>Zamia </i><i>erosa </i>and angiosperm <i>Guaiacum officinale</i> of Zygophyllaceae which are introduced collected in the Darwin Botanic Gardens, and were carried out light microscope and electron microscope observed research to tracheary element and parenchyma tissue cells of leaflet, rachis and stem. The results showed that there are more vessel elements in their xylems;the length of vessel element of Cycadaceae with Zamiaceae are not obvious difference, the length of vessel element of angiosperm <i>Guaiacum officinale</i> is shorter, but their diameter is smaller, we thought that the characteristics which the length of vessel element is longer and the diameter is bigger are more evolutionary, because thus vessel, their number which interconnected points of possessed perforations’ end walls of vessel element is fewer, and the passageway space is larger so that the conduction speed and quantity are faster and more in unit length range and unit time. These vessels are annular vessels, spiral vessels, scalariform vessels, reticular vessels, pitted vessels and scalariform-pitted vessels, etc. In the transverse section, the vessel elements of Cycadaceae and Zamiaceae are circular, polygonous, more similar to vessel characteristics of <a name="OLE_LINK73"></a>leaf and stem of some angiosperms;however, the number of circular vessel of <a name="OLE_LINK21"></a><i>Guaiacum </i><i>officinale</i> is more, about occupy 35%, others are polygonous. The diameter of vessel is that annular vessel, spiral vessel is least, scalariform vessel or scalariform-reticular vessel is medium, reticular vessel and pitted vessel are the biggest, the characteristic is same as angiosperm. In <i>Cycas conferta</i>, etc. plants often can see several large perforations in the end walls, some species are several big scalariform or pitted perforations formed multiple perforation plates, in many vessel element lateral walls, there are some perforations formed a horizontal transport avenue of aqueous solution. The scale of diameter of <i>Cycas</i> vessel element is similar to that of <i>Zamia</i>, but the diameter of more vessel elements of <i>Cycas angulata </i>and<i> Cycas conferta</i> is bigger than the latter, and is bigger than that of <i>Guaiacum officinale</i>, although <i>Cycas</i> plants are more primitive than <i>Zamia</i><i> </i>plants, and <i>Guaiacum officinale</i> is more evolutionary, but the scale of vessel diameter of <i>Cycas</i> plants is similar to <i>Zamia </i>or bigger than the latter, even larger than <i>Guaiacum officinale</i>, these showed that cycads have evolutionary and more developed characteristics in aqueous solution transport system. In <i>Guaiacum officinale</i>, more vessel element has been not seen the ridges in the different directions of side walls which can make vessel has more mechanical supportability, but some possessed the ridges;however, more vessel elements are twist shape and can twist together each other, thus the state can increase their mechanical supportability, and their synergy with fiber elements which is longer with a twist shape, therefore their capability of xylem conduction and the combine mechanical support capability with mechanical tissue are also stronger. In the respect of observed parenchyma tissue, any parenchyma tissue cells are without perforation, all cell walls are smoothed and like a membrane. Aimed at only one or two people pointed the query about Jeffery’s method, some scholars have made comparative researches, their research used as following methods: 1) The fresh materials were cut sections 1 - 2 mm thick by hand (the query person provided and thought right method), were examined with SEM. 2) The materials were treated by Jeffrey’s Fluid and observed with SEM and so on. The results showed that the pit membrane, the remnants in the perforation and the structural characteristics of perforations were not different;and the results of our comparative research in past time and this research all justified that Jeffrey’s method is reliable and reasonable. Meanwhile, our research results showed that only vessel element can form perforation, in other all parenchyma tissue cells cannot form perforation are also proved that the perforations of vessel element are naturally inherited character. Analyzed from the structural characteristics, although they distributed so far apart from each other, they are a well and unified taxonomy system;we thought that Australia’ most species or all species of Cycadaceae came from Asia, and it is impossible from Africa, because the latter only has one more evolutionary species and lack of fossil of Cycadaceae, these species of Cycadaceae are the descendants of ancestor species;America possessed more genera of Zamiaceae, this family is mutual with Africa and Australia, we thought that these genera of Zamiaceae in Australia and America came from Pangea before continental drift in Jurassic Period, this family is also maybe one of the proofs to Australia drifted from Pangea to present position after Jurassic Period. The characteristics of tracheary element of several different genera of cycads and angiosperm further showed that more primary species or taxon, their more tissue characteristics are not also more primary, because of the need to adapt the environment, they are also constantly evolving. The research is important significant and theory reference to understand cycads evolutionary aqueous solution transport system, and understand the ecological adaptation mechanism which why present cycads of 3 families in world major distributed in tropical or subtropical regions, even many drought and barren areas.
文摘Active restoration is a critical component of biodiversity conservation for degraded tropical forest ecosystems caused by artisanal gold mining, and the success of restoration is dependent on native species selection. However, significant knowledge gaps exist regarding when and where to plant trees. This article reports on a revegetation trial undertaken in St Elizabeth, Mahdia, Guyana, to assess the survival and RGR (Relative Growth Rate) of three native woody trees and shrubs planted within three years old Acacia mangium Willd trees pruned and unpruned blocks. ANOVA (Analysis of Variance) for a completely randomized block design with four blocks, two pruned and two unpruned, within A. mangium plots. Biochar treatment was added to the plants during transplanting. Thirty-six (36) wildlings of Humiria balsamifera (Aublet.) (Tauroniro), Goupia glabra Aublet (Kabukalli), and Vismia guianensis (Aublet.) Choisy (Bloodwood) were collected and raised in a tree nursery for two weeks. The native plants were transplanted 3 m apart, survival observations and each seedling’s initial height and diameter were measured and recorded. After the experiment, 13% of seedlings from a population of 720 had died, with the highest mortality being experienced at the 92 days of the experiment (t ≤ 122 days). While the overall survival rates were high, emphasizing the importance of field trials on native and exotic species in different environments is essential to fill the knowledge gaps on suitable species for restoration in degraded areas with other land use histories.
基金The financial support of CLP Holdings Limited is acknowledged for supporting KFBG's ongoing applied forest restoration research.
文摘Both abiotic conditions and management influence the success of forest restoration.Despite growing interest and practical effort in restoring degraded forest landscapes,understanding of how disparate factors,such as terrain,soil conditions,climate and silvicultural treatments,directly or collectively control species performance and shape community recovery remains limited.In this study,we assessed how topography and management intervention affect seedling survival and growth in the early stages of restoration.To do so,we established seven experimental plots,each measuring 20 m×20 m(400 m2)subdivided into 48 subplots,in coarse,anthropogenic grassland on a mid-elevation mountain slope in Hong Kong,and planted a total of 3975 native tree seedlings belonging to 12 tree species within them.To characterise topography,we modelled the elevation,slope,convexity and aspect of each subplot.Two types of tree guard(enclosed blue plastic sleeve and open yellow mesh),two types of fertiliser(organic and inorganic)and cardboard weeding mats were used to assess the impact of management interventions on the establishment of the seedlings.Survivorship,height and basal diameter were measured at 1,2 and 4 years after planting.We used generalised linear models to examine the effect of these factors and their interactions on seedling survival,and we applied linear models and hierarchical partitioning to explore their relative importance in determining the relative growth rate(RGR)of each species.The most parsimonious models were selected using the Akaike Information Criterion.Survivorship was 98.1%,95.2%and 86.4%across all plots in the first,second and fourth year,respectively.On average,topographic and management variables explained 1.48–3.34%of total variation in RGR,respectively,for all species.The models revealed that type of tree guard,aspect and elevation were the most important factors explaining RGR and survival.Results of hierarchical partitioning by species and growth period showed that the key determinants of performance vary by species and shift over the course of early seedling establishment,emphasising the importance of both spatial and temporal scales in the restoration of degraded tropical forests.Our findings support the use of enclosed tree guards and fertiliser to improve survivorship and growth across a range of broadleaved Asiatic species.All potential limiting factors pertaining to both site factors and management,as well as their interactions,should be considered in restoration planning to maximise restoration success.
基金provided by the Kone Foundation (Finland) and from the TAITATOO project (110294, Academy of Finland)
文摘The relationship between soil properties and spatial distribution of native woody species was studied in three Taita Hills forest fragments which, although degraded, are ranked among 34 biodiversity hotspots of the world due to their high biodiversity of both plant and animal species. This relationship was assessed by using Spearman correlation and principal component analyses （PCA）. The results of these analyses should be useful in instituting forest restoration programs that are crucial for the forests. Both the soil and vegetation studied were sampled from 17 subplots in the natural forest fragments of Ngangao （120 ha）, Chawia （86 ha） and Mbololo （185 ha）. The soil variables measured were： pH, texture, soil nutrients of C, N, Ca, P, K, Mg and Na. In total 36 native tree species from 13 families were identified from the three forest fragments. Ordination results show that axis 1 accounted for 35% and axis 2 for 25% of the total variation in species composition, indicating that the structure of vegetation is related to two major environmental gradients. The correlation analyses of species and soil properties showed that Na and clay particles were the most important determinants of species distribution; pH and soil variables such as C, N, Ca and P also played minor roles. Unexpectedly, some species （e.g. Psychotria petitii） showed positive relationships with Na attributed to possible substitution for K. Relationships with P were both positive （e.g. Craibia zimmermannii） and negative （e.g. Albizia gummifera） with some species, attributable to pH levels. An ANOVA for soil variables showed that there were differences in the Ca content in Mbololo （due to the parent material） and P in Ngangao where a special relationship was observed between some of the species. The presence of gaps accounted for the distribution of seedlings but not for the saplings, whose distribution responded more to factors similar to those to which mature trees respond. Soil-species relationships that were established may be utilized along with soil analyses when choosing native species for restoration.
基金support by the Open Access Publication Funds of the Gottingen University
文摘Forests over limestone in the tropics have received little attention and limestone forests in Vietnam have been overlooked to an even greater extent in terms of tree physiology. In Ba Be National Park, Vietnam, soil water availability in limestone forests seems to be the most limiting factor in the dry season. Therefore, in order to enhance the preliminary knowledge of choosing native tree species for enrichment planting in the restoration zone, characteristics of the 20 native tree species to soil water stress were investigated in a limestone forest. One-ha plot each consisting of twenty-five 20 m × 20 m plots was established in undisturbed forests. All trees ≥ 10 cm DBH were measured in 20 m × 20 m plots, while twenty-five 5 m × 5 m subplots were established in order to sample the regeneration of tree species with a DBH < 10 cm. The Scholander apparatus and freezing point osmometry were used in order to measure the leaf water potential (Ψw) and leaf osmotic potential (Ψπ) of the 20 native tree species, respectively in this study. 61 species belonging to 34 families of all trees with a DBH ≥ 10 cm were recorded in one ha, while 31 species representing 18 families of trees < 10 cm DBH were identified in 625 m2. The 20 species’ leaf water and osmotic potential values revealed significant differences among species. The maximum leaf water potential was not affected by any anticipated sources of variation, while the minimum water potential, however, showed significant variation to soil water stress. The results in the study area emphasized the importance of water factors in influencing tree species distribution;it could be concluded that native species with wide water potential ranges would be better able to withstand water changes and might be thus good candidates for reforestation (enrichment planting) in limestone areas.
文摘Propagation of exotic plant species is found in many regions of Madagascar Island. This work aims to describe the impacts of the propagation of Grevillea banksii on soil microbial activities and on the regeneration of two native tree species （Intsia bij＇uga and Dalbergia trichocarpa） in the eastern part of Madagascar. The study was conducted within Ianjomara forest where some types of the vegetation are observed such as an area characterized by grassland （P 1）, by homogeneous population of G. banksii （P2） and by a natural forest composed mainly of L bijuga or D. trichocarpa （P3 and P4）. Structure of mycorrhizal fungi communities and associated microorganisms were described on soils from each study plot. The development of I. b^juga and 1）. trichocarpa, was evaluated 4 months after planting on P1, P2, P3, P4 soils formerly colonized by G. banksii. According to the nutrients availability on each soil type, the development of G. banksii was accompanied or not by a high formation of cluster roots. The authors＇ results also show that soil occupied by G. banksii decreased the global microbial and phosphatase activities of soil especially on soil within a high density of cluster roots. Moderately mycotrophic, G. banksii disturbs the structure and the dynamics of symbiotic microflora such as endomycorrhizal fungi （MA） and rhizobia associated with the two native tree species. The findings illustrate the negative impact of G. banksii propagation on the regeneration and the conservation of native tree species in Madagascarian forest.
文摘Native tree species play a very important role in the planning and design of urban green landscape. It has strong adaptability to the local natural environment, beautiful landscape, convenient management, and has the cultural connotation of the city. It fully reflects the morphological characteristics of the local native plant landscaping, and is of great significance to the establishment of an ecological city. Based on the investigation of the application of native tree species in the urban green space of Huaian City, Jiangsu Province, the author analyzed the advantages and disadvantages of native tree species planting, and provided some practical planning, design and planting suggestions for good planting and management of native tree species in the urban green space scenic spots of Huaian City, which can be used as a reference for the urban landscape planning and design departments and nursery stock production departments of cities and counties in Huaian City.
基金part of the research project ‘Legal frameworks for Conservation of Biodiversity and Ecosystem Services in the Himalayas (HIMALINES)’ funded by the Norwegian Research Council (190153/V10) Olaf Grolles Legat
文摘Invasive plant species are exerting a serious threat to biological diversity in many regions of the world. To understand plant invasions this study aims to test which of the two plant invasiveness hypotheses; ‘low native diversity' vs. ‘high native diversity', is supported by the regional distribution patterns of invasive plant species in the Himalayas,Nepal. This study is based on data retrieved from published literatures and herbarium specimens. The relationship between invasive plant species distribution patterns and that of native plant species is elucidated by scatter plots, as well as by generalized linear models. The native plant species and invasive plant species have similar distribution patterns and the maximum number of invasive plant species is found in the same altitudinal range where the highest richness for native tree species is found. There is a clear trend of higher invasive plant richness in regions where native tree species richness is relatively high.Consequently, the native plant richness is highest in the central phytogeographic region, followed by the eastern and the western regions, respectively. The invasive plant species also follows a similar trend.Additionally, the invasive plant species richness was positively correlated with anthropogenic factors such as human population density and the number of visiting tourists. This study supports the hypothesis that ‘high native diversity' supports or facilitates invasive plant species. Further, it indicates that nativeand invasive plant species may require similar natural conditions, but that the invasive plant species seem more dependent and influenced by anthropogenic disturbance factors.
文摘Invasive alien plant species have threatened the integrity of ecosystems and threatened biological integrity throughout the world. In the Nyika National Park, a number of alien invasive plant species have been reported. These invasive alien plants are reported to be very difficult that have caused adverse ecological, economic and social impact. The main objective of this study is to assess the environmental impact of plant invasive alien species in Nyika National Park in order to ascertain means of addressing the possible effects on the biodiversity. This study adopted an exploratory stance in order to answer <span>the hypotheses where purposive and simple random sampling was used. P</span>ur<span>posive sampling was only used to the staff of Nyika while simple random s</span>ampling was used to collect data from households surrounding Nyika National Park. The results revealed that invasive alien plant species have some ecological impacts of on the biodiversity of the Nyika National Park like change in physical habitats such as loss of native habitats, alteration of ground water regime, drying of rivers, loss of native species and alteration of biomass. The study would therefore be important to policy makers in guiding and devel<span>opment of policies and guidelines governing eradication of invasive alien pl</span>ant species. The Department of National Parks and Wildlife (DNPW) can form partnership with various stakeholders with a clearly stated intention of developing a relationship, based on collaboration to enhance the control of invading alien plant species and the best management practices.
文摘Reforestation and reforestation efforts are generally dependent on the species recommended by the government. In the Philippines, most reforestation activities use Gmelina arborea, Acacia mangium, and Swietenia macrophylla due to their usual economic returns. Thus, the use of native species is less favored over exotic species. This paper considered the species preferences of the local community as involved in reforestation activities in Zambales. Assessment of the stakeholders’ preferences was based on a listing of species given by the respondents and community perceived benefits or uses. Familiarity of the respondents with the species presented to them was also considered in the analysis.
文摘Farmers are eager to know the various types of weeds in paddy fields.This will help in choosing the best weed management practice for effective weed control as well as reducing rice yield losses.The objectives of the study are to identify the weeds species affecting the rice field,to assess the composition of weeds species,to classify the weed species into different families,genera,species,common names,Hausa names,lifecycles,life forms,native/exotic species,propagation and uses,and to determine the dominant weed species.Random vegetation surveys were conducted.Weeds observed were photographed,and prepared as herbarium specimens.Standard key manuals and checklists were utilized for weed identification and later organized using the Angiosperm Phylogeny Group(APG)classification system.A total number of 72 plants species distributed within 16 families and 50 genera were inventoried.The annuals(66.67%)were the dominant weed followed by perennials(33.33%)while biennials were the least.The broad leaves were the dominant weed(44.61%)identified followed by Poaceae(27.7%)and Sedges(11.11%).Results obtained from this study could be useful in choosing the best management practice and in making a decision on the choice of herbicides and directing research towards improved weed control measures.
文摘Hancornia speciosa‘Gomes’,commonly known as mangabeira,is a fruit-bearing tree native to Brazil that plays a crucial role in sustaining its native biome,restoring degraded areas,and improving the socio-environmental conditions of these regions.The use of colored materials and bioinputs can help improve the quality of seedling production of Hancornia speciosa.This study aimed to evaluate the use of colored seedling tubes and a Chlorella vulgaris-based bioinput in developing Hancornia speciosa seedlings.The experiment was conducted at the Mato Grosso do Sul State University(UEMS),in Cassilândia,MS,using a completely randomized design in a 5×2 factorial arrangement.Treatments included colored reflective tubes(blue,white,red,yellow,and black)and bioinput application(absence or presence).The Hancornia speciosa seeds were collected near the Cassilândia campus and the Chlorella vulgaris-based bioinput was produced at the Microalgae and Biotechnology Laboratory of the Centro de Desenvolvimento Sustentável do Bolsão Sul-Mato-Grossense(CEDESU).The bioinput was applied at sowing and after 30,60 and 90 days after emergence(DAE),totalizing three applications.An increase in plant height,number of leaves,chlorophyll a and total,CO_(2) assimilation rate,water use efficiency was observed.The combination of tube color and the presence of the Chlorella vulgaris bioinput significantly improved biometric traits,seedling quality index,chlorophyll a and total chlorophyll content,and CO_(2) concentration,thus enhancing the seedling quality and potentially increasing field establishment and survival rates.
基金Supported by Special Fund for Basic Research Operating Expenses of Nonprofit Research Institutions at the Central Level(BRF090202)~~
文摘[Objective] The aim was to study pollen morphology of Pennisetum native species.[Method] We carried out the observation by optical microscope and scanning electron microscope on six materials of pollen grains including three species and three transmogrifications from one variant of Pennisetum native species.[Result] The pollen grains were globose or subglobose.Germination aperture which located at distal side was singular and its circumambience was thickened.Pollen wall which had two layers was thin and easy to be crimpled.There were obvious differences between ektexine ornamentations as well as particle sizes.[Conclusion] The question of low seed-setting rate of Pennisetum native species had relations with the withered pollen morphology to some extent.The differences between pollen morphology as well as ektexine ornamentations accorded with the division of species and variants from Pennisetum.In addition,the relationship between pollen morphology and seed-setting rate provided references to introduce good grass seed and choose breeding parent materials of Pennisetum.
基金Under the auspices of National Natural Science Foundation of China(No.31600376,41571053,71533005)
文摘Urban plants provide various ecosystem services and biodiversity for human well-being. It is necessary to examine the plant species and functional traits composition and the influencing factors. In this study, a field survey was conducted using the tessellation-randomized plot method to assess the plant species and functional traits variability in greenspaces across eight land use types(LUTs) in the built-up areas of Beijing, China. Results showed that the woody plants in the built-up areas of Beijing comprised 85 non-native species(57%), 21 pollen-allergenic species(14%), and 99 resistant species(67%). Residential areas, community parks and institutional areas had higher woody plant species richness than other LUTs. Native and extralimital native species were more widespread than exotic species. Proportions of species with resistances were low except for cold-and drought-resistance; consequently, a high intensity of management and maintenance is essential for survival of plants in this urban area. Caution should be exerted in selecting plant species with resistance to harsh conditions in different LUTs. Housing prices, distances from the urban center, years since the establishment of LUTs and greening rate were strongly correlated with the plant functional traits and species diversity. Urban forest managers should consider plant functional traits and LUT-specific strategies to maximize both forest and human health.
文摘Background:So far,macroecological studies in the Himalaya have mostly concentrated on spatial variation of overall species richness along the elevational gradient.Very few studies have attempted to document the diference in elevational richness patterns of native and exotic species.In this study,this knowledge gap is addressed by integrating data on phylogeny and elevational distribution of species to identify the variation in species richness,phylogenetic diversity and phylogenetic structure of exotic and native plant species along an elevational gradient in the Himalaya.Results:Species distribution patterns for exotic and native species difered;exotics tended to show maximum species richness at low elevations while natives tended to predominate at mid-elevations.Native species assemblages showed higher phylogenetic diversity than the exotic species assemblages over the entire elevational gradient in the Himalaya.In terms of phylogenetic structure,exotic species assemblages showed majorly phylogenetic clustering while native species assemblages were characterized by phylogenetic overdispersion over the entire gradient.Conclusions:The fndings of this study indicate that areas with high native species richness and phylogenetic diversity are less receptive to exotic species and vice versa in the Himalaya.Species assemblages with high native phylogenetic overdispersion are less receptive to exotic species than the phylogenetically clustered assemblages.Diferent ecological processes(ecological fltering in case of exotics and resource and niche competition in case of natives)may govern the distribution of exotic and native species along the elevational gradient in the Himalaya.
基金funded by Coordenacao de Aperfeicoamento de Pessoal de Nível Superior(CAPES)。
文摘Investment in silvicultural techniques is noticeably lacking,especially in breeding programs for non-conventional wood species.Studying genotype×environment interaction(G×E)is essential to the development of breeding programs.Thus,this study aimed to estimate genetic diversity of and the effects of G×E interaction on two progeny tests of Cordia trichotoma,including the estimation of genetic gain and genetic diversity after selection.For the experiment,30 progenies of C.trichotoma were tested at two sites with differing soil textures.Diameter at breast height(1.30 m above soil surface,dbh-cm),total height,diameter at 30 cm from the soil,first branch height,and survival were all monitored for four years.Statistical deviance,best linear unbiased estimator,and harmonic mean of relative performance of genetic values(MHPRVG)were all calculated to predict breeding values,estimate genetic parameters,and analyze deviance.All quantified traits varied significantly among progenies by soil type,with greatest variation recorded for genetic variability.Heritability of the progenies led to predictions of genetic gain,ranging from 7.73 to 15.45%,for dbh at four years of age.The calculated decrease in genetic diversity after selection showed that this parameter should be monitored in subsequent breeding cycles.G×E was low for all tests.The best-performing progenies proved most stable and best adapted to the different environmental conditions tested.
文摘Aims understanding relationships between the distributions of species and their surrounding environment provides a basis for forecasting how species will respond to future environmental changes.In this study,we examined the effects of environmental factors and human devel-opmental features associated with disturbances on probability of occurrence of juveniles of invasive Triadica sebifera and three native plant species,Baccharis halimifolia,Ilex vomitoria and Morella cer-ifera within a typical coastal transition in coastal mississippi,USA.Methods We recorded presence of juveniles of focal species and measured environmental factors(soil salinity,canopy openness,soil texture and soil carbon to nitrogen ratio)along an 11.3 km transect located at grand bay National Estuarine research reserve.Further,we doc-umented anthropogenic features and associated activities as a proxy for human disturbance.Important Findings With the exception of I.vomitoria,all other species occurrences were significantly influenced by an interaction between soil salinity and canopy openness.The occurrence of I.vomitoria sharply decreased with salinity.B.halimifolia occurrence peaked at moderate levels of salinity and low to moderate levels of canopy openness.occurrences of M.cerifera and the invasive T.sebifera were highest at low levels of salinity and canopy openness.These results indicate that salinity is a strong driver that limits distribution of juvenile native and invasive species in coastal transitions.logistic regression confirmed the positive effects of anthropogenic disturbances on T.sebifera and I.vomitoria occurrence.It appears that while soil salinity is likely to drive retreat of the seaward boundaries of woody plant species distributions,increased human developments along the coast likely enhance the inland spread of species,in particular the invasive T.sebifera by increasing distur-bances and facilitating dispersal.results from this study can offer insight for the development of T.sebifera management and preventive meas-ures for further spread along coastal areas of the southeastern USA.
