Soil heterotrophic respiration and its temperature sensitivity are affected by various climatic and environmental factors.However,little is known about the combined effects of concurrent climatic and environmental cha...Soil heterotrophic respiration and its temperature sensitivity are affected by various climatic and environmental factors.However,little is known about the combined effects of concurrent climatic and environmental changes,such as climatic warming,changing precipitation regimes,and increasing nitrogen(N)deposition.Therefore,in this study,we investigated the individual and combined effects of warming,wetting,and N addition on soil heterotrophic respiration and temperature sensitivity.We incubated soils collected from a temperate forest in South Korea for 60 d at two temperature levels(15 and 20℃,representing the annual mean temperature of the study site and 5℃warming,respectively),three moisture levels(10%,28%,and 50%water-filled pore space(WFPS),representing dry,moist,and wet conditions,respectively),and two N levels(without N and with N addition equivalent to 50 kg N ha^(-1)year^(-1)).On day 30,soils were distributed across five different temperatures(10,15,20,25,and 30℃)for 24 h to determine short-term changes in temperature sensitivity(Q_(10),change in respiration with 10℃increase in temperature)of soil heterotrophic respiration.After completing the incubation on day 60,we measured substrate-induced respiration(SIR)by adding six labile substrates to the three types of treatments.Wetting treatment(increase from 28%to 50%WFPS)reduced SIR by 40.8%(3.77 to 2.23μg CO_(2)-C g^(-1)h^(-1)),but warming(increase from 15 to 20℃)and N addition increased SIR by 47.7%(3.77 to 5.57μg CO_(2)-C g^(-1)h^(-1))and 42.0%(3.77 to 5.35μg CO_(2)-C g^(-1)h^(-1)),respectively.A combination of any two treatments did not affect SIR,but the combination of three treatments reduced SIR by 42.4%(3.70 to 2.20μg CO_(2)-C g^(-1)h^(-1)).Wetting treatment increased Q_(10)by 25.0%(2.4 to 3.0).However,warming and N addition reduced Q_(10)by 37.5%(2.4 to 1.5)and 16.7%(2.4 to 2.0),respectively.Warming coupled with wetting did not significantly change Q_(10),while warming coupled with N addition reduced Q_(10)by 33.3%(2.4 to 1.6).The combination of three treatments increased Q_(10)by 12.5%(2.4 to 2.7).Our results demonstrated that among the three factors,soil moisture is the most important one controlling SIR and Q_(10).The results suggest that the effect of warming on SIR and Q_(10)can be modified significantly by rainfall variability and elevated N availability.Therefore,this study emphasizes that concurrent climatic and environmental changes,such as increasing rainfall variability and N deposition,should be considered when predicting changes induced by warming in soil respiration and its temperature sensitivity.展开更多
The eff ect of seasons on the soil microbiome in a Larix gmelinii forest of Mohe,China,where winter temperatures are generally below−40°C,was evaluated with metagenomics analysis.Taxonomic profi ling using sequen...The eff ect of seasons on the soil microbiome in a Larix gmelinii forest of Mohe,China,where winter temperatures are generally below−40°C,was evaluated with metagenomics analysis.Taxonomic profi ling using sequencing information revealed that Proteobacteria,Actinobacteria,Acidobacteria and Verrucomicrobia were the dominant phyla in spring,summer,and fall,as were Bradyrhizobium,Chthoniobacter,Streptomyces,Acid Candidatus Koribacter at the genus level.Some species that were abundant in spring and fall greatly diminished in abundance in summer.Clusters of orthologous groups(COG)of proteins,carbohydrate-active enzymes(CAZy),Kyoto Encyclopedia of Genes and Genomes(KEGG)and NCBI databases were used to elucidate the function of diverse proteins and metabolites of the microbial community of L.gmelinii forest.COG analysis showed that fewer genes were detected in spring than in fall and summer,indicating that many soil microbes in the L.gmelinii forest were not tolerant to cold.Based on KEGG analysis,some pathways in the soil microbes were activated in spring and autumn and deactivated in summer.CAZy analysis revealed that most CAZy were more active in summer than in spring or autumn and were severely inhibited in the spring.Many functional pathways,proteins,and CAZy involved in the community changes were concerned with cold or heat resistance.Therefore,the soil in the L.gmelinii forest can be a valuable resource for further research on heat and cold tolerance of soil microbes.展开更多
Rice husk biochar inoculated with Bacillus megaterium(BM)(referred to as BM-inoculated biochar, BMB) and uninoculated rice husk biochar(RHB) were added to soil at two rates(0.5%, as BMB1 and RHB1, respectively, and 1....Rice husk biochar inoculated with Bacillus megaterium(BM)(referred to as BM-inoculated biochar, BMB) and uninoculated rice husk biochar(RHB) were added to soil at two rates(0.5%, as BMB1 and RHB1, respectively, and 1.0%, as BMB2 and RHB2, respectively) in an incubation experiment to comprehensively evaluate their effects on basic soil properties, phosphorus(P) fractions, bacterial community composition, and P-cycling genes.展开更多
We investigated the relationships between dehydrogenase activity and the physicochemical properties of mountain soils over three and five years from Norway spruce(Picea abies L. Karst) logging residue spot burning and...We investigated the relationships between dehydrogenase activity and the physicochemical properties of mountain soils over three and five years from Norway spruce(Picea abies L. Karst) logging residue spot burning and the occurrence of epigeic carabid beetles. Six study sites were utilised, including18 study plots(nine plots in a mixed coniferous mountain forest site and nine plots in a mixed broadleaf mountain forest site), with five replicate pitfall traps at each site located in southern Poland.Soil samples from the organic horizon were taken for p H, organic carbon, nitrogen, base cation content,acidity and dehydrogenase activity determination.Carabid beetles were monitored in weekly intervals during the period of July to August 2016. The burning of logging residues led to modified soil properties,especially the dehydrogenase activity. In all the tested variants, the activity was higher in soil samples after the burning in comparison to the control variants. We show no positive correlation between dehydrogenase activity and the number of carabid specimens. The preferences of dominant predatory hygrophilous carabids to acid habitats with weakly decomposed organic matter were proven. Simultaneously, the soil organic matter content was positively related to the carabid abundance. The significant impact of forest site conditions and the date of logging residue burning on the number of caught specimens were confirmed. In contrast, no relationships between the species richness, species diversity, mean individual biomass and spot burning effect were found. This work supports the recommendation of spruce fine woody debris utilisation by spot burning on mountain regions with rich habitats presenting moderate wet conditions and small land falls.展开更多
Background: Fires have a fundamental impact on phytocoenoses and, depending on the size of the fire, can have a positive or negative effect. The role of fires in the formation of the species composition of plants, res...Background: Fires have a fundamental impact on phytocoenoses and, depending on the size of the fire, can have a positive or negative effect. The role of fires in the formation of the species composition of plants, restoration of stands and changes in soil properties is well studied. However, the long-term relationship between forest management methods, soil properties and epigeic entomofauna assemblages in post-fire areas is still not clear. The effects of Scots pine stand management methods on biochemical soil properties and ground beetle assemblages in the largest post-fire area in Central Europe after the second World were investigated. The study was conducted in the Rudy Raciborskie Forest district in southern Poland. The soil properties and epigeic beetle community structure were analysed. The research covered areas with natural and artificial pine regeneration, which were subjected to various care treatments.Results: The tendency for higher accumulations of organic matter in the soil of stands that underwent natural regeneration was proven. The stimulating role of soil organic carbon on the activity of dehydrogenases in the soil of naturally renewed areas with silvicultural treatment(NRAT) was noted. Regardless of the manner of stand regeneration, the activity of β-glucosidase was higher in the areas in which breeding treatments were practised.Furthermore, managed forest stands presented a higher abundance of carabid beetles than stands without treatment practices. Thirteen epigeic beetle species from the families Geotrupidae, Carabidae, Curculionidae,Cerambycidae and Silphidae were captured, with beetles from the first two families being the most numerous. Rare epigeal carabid species in the fauna of Poland and Europe, such as Carabus glabratus(Paykull) and Carabus auronitens Fabr., found appropriate habitat conditions for survival in the post-fire areas. Compared with the other areas, in the NRAT area, there were better stand and soil properties and more features conducive to epigeic entomofaunal occurrences. The highest post-fire content of polycyclic aromatic hydrocarbons was recorded in the soils of the sites that underwent artificial regeneration. The results suggest that preparing the soil before the introduction of new vegetation affects the amount of aromatic hydrocarbons(PAHs).Conclusions: The better performance of the NRAT stand draws attention to the positive aspects of the use of natural regeneration, both from ecological and economic perspectives. The effects of forest management on the amount of soil organic matter after fires have been proven. The natural regeneration of stands was conducive to the accumulation of organic matter. The enzymatic activity of soils is influenced by the renewal method and forest management strategy. The NRAT area was characterized by the highest number of carabid species.展开更多
The genus Diomus Mulsant,1850(Coleoptera:Coccinellidae:Diomini)from China is herein revised.Five species of Diomus are occurring in the Chinese fauna to date,including a new species from the Dafushan Mountains Forest ...The genus Diomus Mulsant,1850(Coleoptera:Coccinellidae:Diomini)from China is herein revised.Five species of Diomus are occurring in the Chinese fauna to date,including a new species from the Dafushan Mountains Forest Park,Guangzhou,Guangdong,namely D.dafushanensis Bi,Peng&Chen,sp.nov.Nomenclatural history,diagnosis,illustrations and distribution were provided for each species.A key to the native species of Diomus from China is also presented.展开更多
A novel embedded sensor network records changes in key climatic-environmental variables over a range of altitude in the BaekduDaegan Mountain （BDM） of Gangwon Province in Korea, a protected mountain region with uniq...A novel embedded sensor network records changes in key climatic-environmental variables over a range of altitude in the BaekduDaegan Mountain （BDM） of Gangwon Province in Korea, a protected mountain region with unique biodiversity undergoing climate change research. The investigated area is subdivided into three horizontal north-south study areas. Three variables, temperature （T, °C）, relative humidity （RH, %）, and light intensity （LI, lumens m-2, or lux, lx）, have been continuously measured at hourly intervals from June, 2olo to September, 2011 using HOBO H8 devices at lO fixed study sites. These hourly observations are aggregated to monthly, seasonal and annual mean values, and results are summarized to inaugurate a long-term climate change investigation. A region wide T difference in accordance with altitude, or lapse rate, over the interval is calculated as o.4°C l00 m-1. T lapse rates change seasonally, with winter lapse rates being greater than those of summer. RH is elevated in summer compared to other seasons. LI within forestland is lower during summer and higher during other seasons. The obtained results could closely relate to the vegetation type and structure and the terrain state since data loggers were located in forestland.展开更多
The large larch beetle,Ips cembrae,is a significant pest causing the death of larch.In 2020,the attack density of I.cembrae on larch trap trees and standing trees was evaluated using sample sections placed along the t...The large larch beetle,Ips cembrae,is a significant pest causing the death of larch.In 2020,the attack density of I.cembrae on larch trap trees and standing trees was evaluated using sample sections placed along the trunk.As a defensive measure against I.cembrae,trap trees were highly effective in both spring and summer.The attack density increased with increasing trap tree surface area/volume.Galleries were established evenly throughout the entire trunk including the thin upper portion.When the number of trap trees was low and their capacity full,a continual aggregation of adults occurred due to pheromone communication,leading to attacks on healthy standing trees in the immediate vicinity.It was found that I.cembrae attacked standing trees from the trunk base,with a continual colonization of the stem up to 70%of the tree height in a time-differentiated progression of development stages.The attack density of I.cembrae on standing trees was up to 40%lower than on the trap trees.展开更多
To study the effect of manganese exposure on the herbivorous insect Lymantria dispar asiatica,fourthinstar larvae were fed a MnCl_(2)-amended diet(LdMn)for 84 h(0.40 mmol MnCl_(2)/g diet).Larvae were weighed before an...To study the effect of manganese exposure on the herbivorous insect Lymantria dispar asiatica,fourthinstar larvae were fed a MnCl_(2)-amended diet(LdMn)for 84 h(0.40 mmol MnCl_(2)/g diet).Larvae were weighed before and after the diet administration to assess larval gain in mass under manganese exposure.The whole bodies of half of the survivors were ground in liquid nitrogen for measuring enzyme activities and total antioxidant capacity(T-AOC).The intestinal tracts of the remaining survivors were collected and immediately frozen in liquid nitrogen for 16S rDNA sequencing of gut microbiota.Larvae under manganese stress lost significant mass(p<0.05).The activities of digestive and antioxidant enzymes and T-AOC,but not trehalase and polyphenol oxidase,were significantly higher after Mn exposure,(p<0.05).A Venn diagram illustrated that the gut microbial OTU composition in the larvae also changed.Community pies and correlation heatmaps also showed different relative abundances of gut microbes.In other words,species quantity and relative abundance of gut microbes agreed with PCoA visualization and indicated that the gut microbial community in L.dispar asiatica larvae differed significantly between control and LdMn.Functional classification also suggested that exposure to manganese stress significantly decreased gut microbial coenzyme transport and metabolism in L.dispar asiatica larvae.These results further our understanding about stress response of L.dispar asiatica larvae.展开更多
The aim of this research paper is to investigate the land cover changes in Sudan during the period 2001-2013 by using the MODIS data and to identify climatic factors influencing the land cover. SPSS v 17 software was ...The aim of this research paper is to investigate the land cover changes in Sudan during the period 2001-2013 by using the MODIS data and to identify climatic factors influencing the land cover. SPSS v 17 software was used to investigate the correlation of climatic factors with vegetation cover;also ArcGIS v 10.2 software was used to analyze the NDVI data. The results indicate that the monthly average time scale, NDVI value curve distribution during the year, July to October as the center to both sides of decreasing vegetation cover in other months. In the spatial distribution of mean NDVI in Sudan, a high value was found in the southern part. On the other hand, a low value of vegetation cover was found in northern part. NDVI spaces mean presenting features values: autumn followed by summer then winter. By calculation of average annual and seasonal-NDVI values, it was deduced that the main vegetation cover type was increasing in winter and summer seasons at the rates of 0.014/10a and 0.008/10a, respectively. While winter-NDVI was decreasing the rate of 0.001/10a and 0.026/10a in autumn and on the annual scale, respectively. Annual NDVI showed a significant degradation (area = 12705.7 km2, 0.5% of total area) in the middle and eastern parts and significant improvement (area = 22485.4 km2, 0.9 % of the total area) in the southern part of the country due to the increase in precipitation and decrease in temperature. Mean summer and autumn-NDVI showed a significant difference 0.01% significance level with mean summer and autumn precipitation (correlation coefficients = 0.955 and 0.953, respectively). While there was a significantly negative relationship between mean summer and autumn-NDVI with mean summer and autumn temperature at 0.01% significance level (correlation coefficients = −0.270 and −0.820, respectively).展开更多
Land use activities (LUA) have a significant impact on the level and situation of vegetation characteristics and in turn affect human population as they are considered as the main global environmental changes. This st...Land use activities (LUA) have a significant impact on the level and situation of vegetation characteristics and in turn affect human population as they are considered as the main global environmental changes. This study analyzed land use patterns in three different locations in Khartoum, Sudan: banks of River Nile, Blue and White Nile. The main objective of the present study were 1) to assess the changes in land use and their impact on vegetation cover and sustainable livelihoods of the population, and 2) to identify the factors behind land use changes along the Banks of Niles, Khartoum State. The study data used were field survey (questionnaire) which revealed the existence of five types of land use patterns: roads, human settlements, agricultural and plantations farms, and industrial of brick-kilns making and investment areas. The primary data were collected through social survey (questionnaire) as face-to-face interviews with local communities in the study area and by observations. The secondary records during the field survey were collected from the Ministry of Agriculture and Forestry, and the Forest National Corporation (FNC) documents, scientific papers and annual reports. SPSS was used to analyze the data acquired from questionnaires. Results showed that agricultural land, and industrial and residential areas increased while forests and bare lands decreased as a result of changes imposed by the government and local population with consequent land degradation in terms of environmental value and productivity. Interestingly, it was found that the impact of land use on vegetation cover and livelihood of the population was very complex and dynamic and that the main influencing factors in this process were climate fluctuations and human illegal interference. For instance, vast areas in west bank of White Nile were changed from agriculture to residence and investment. In conclusion, land use requires a clear plan for optimum utilization. Various human activities are behind these changes, which have led to deterioration of forest cover and loss of the source of income of local population. Because of such alarming changes, decision makers should initiate efficient plans and management of forests to minimize changes in land cover, especially in arid and semi-arid areas. We recommend that a sound land use plan should be revised often to ensure rehabilitation, reduce vulnerability to desertification and halt the encroachment by construction of facilities and buildings at the expense of environmental issues.展开更多
The aims of this research were to investigate the impacts of climate variations on land use policies, food security and vegetation cover in Gadarif State (eastern Sudan) during 1961 to 2013. Analysis of precipitation ...The aims of this research were to investigate the impacts of climate variations on land use policies, food security and vegetation cover in Gadarif State (eastern Sudan) during 1961 to 2013. Analysis of precipitation and temperature time series revealed that the annual precipitation was decreasing while the temperature was increased in the study area. Precipitation was decreasing at a rate of −50.3 mm/10a, while the temperature was increasing at a rate of 0.02°C/10a. The result of both SPEI and SPI showed that the Gadarif State has been changed to a high frequency of drought during 1961-2013. Sorghum yield showed a significant positive relationship with precipitation during July and October (CC = 0.364 and 0.321, respectively), moreover, a significant positive relationship between Sesame yield and precipitation was observed during July (CC = 0.335). A significant negative relationship between Sorghum yield and mean temperature was observed during the rainy season (July to October) with CC = −0.278. The yield productivity of Sorghum and Sesame had decreased significantly (from more than 800 kg/ha in the 1960s to less than 200 kg/ha in 2000s for Sorghum, while 500 kg/ha in 1960s to 100 kg/ha in 2000s for Sesame). The Mechanized Rain-fed Agriculture (MRA) area of Sorghum and Sesame in the Gadarif State had been increased from 1,058,241 ha to 2,799,655 ha during 1961 to 2013. Thus, we ultimately suggest that in the Gadarif State, policy makers must strive for an increase in yield per unit area by using sufficient fertilizers along with the gradual increment in tendencies of grain production through expansion of the cultivated area.展开更多
General characteristics of Globicornis Latreille and a key of known subgenera of the genus are given. The new species G.（Globicornis） yushuensis sp. nov. from China（Qinghai Province） is described and illustrated.
Background:Nesting trees and habitat represent the key factor underpinning stand selection by forest-dwelling birds.While two large European species–the black stork(Ciconia nigra L.)and white-tailed eagle(Haliaaetus ...Background:Nesting trees and habitat represent the key factor underpinning stand selection by forest-dwelling birds.While two large European species–the black stork(Ciconia nigra L.)and white-tailed eagle(Haliaaetus albicilla L.)–are known to require old,large trees for nesting,we sought to investigate further by comparing species requirements at the levels of the nesting tree,nesting stand,and landscape.This entailed a detailed examination of forest features within circles of radius 15 m surrounding 16 and 19 trees holding the nests of storks and eagles respectively.The same parameters were also checked in the vicinity of 50 randomly-selected mature trees.Results:Our results indicate different nesting preferences,with the eagles entirely confining themselves to Scots pine(Pinus sylvestris L.)–a species also chosen by black storks,which nevertheless regularly favour pedunculate oak(Quercus robur L.).Both species select trees of greater girth than the random ones,but white-tailed eagles choose to nest in the vicinity of patches of mature old stands with a loose canopy,to the extent that nesting trees and surrounding trees are of similar ages.In contrast,black storks prefer“veteran”trees with low-set crowns that are much older than any others in their vicinity.Nesting trees of the eagles are away from roads and close to lakes,while black storks do not avoid roads.Conclusions:As the ages of nesting trees of both species are greater than ages at final cutting in this region’s managed forest,silvicultural measures will need to be adjusted,with small patches of forest spared,or larger areas as“islands”of old-growth.Likewise,as tending and thinning are engaged in,certain trees with horizontal branches will need to remain,with relict trees also left untouched.As it happens,all of these recommendations are anyway key elements of close-to nature silviculture and multifunctional forestry.展开更多
Behavioral predictability,i.e.,short-term intra-individual variability under relatively constant environmental conditions,has only recently begun to gain attention.It is unknown,however,whether predictability of indiv...Behavioral predictability,i.e.,short-term intra-individual variability under relatively constant environmental conditions,has only recently begun to gain attention.It is unknown,however,whether predictability of individuals with distinct mean behavior changes differently as a response to ecological factors such as resource availability.Moreover,the response might be affected by anthropogenic contaminants that are ubiquitous in the environment and that can affect animals' variability in behavior.Here,we investigated the relationship between mean predatory activity and predictability in predatory activity along a prey density gradient in the lynx spider Oxyopes lineatipes.We further examined how this relationship is influenced by insecticides,azadirachtin,and a plant extract from Embelia ribes.We found that all studied variables affected the predictability.In the control and Embelia treatments,that did not differ significantly,the predictability decreased with increasing prey density in a mean behavior-specific way.Individuals with low mean predatory activity were relatively less predictable than were those with high activity from low to moderate prey densities but more predictable at high prey densities.Azadirachtin altered this pattern and the individuals with low predatory activity were less predictable than were those with high predatory activity along the whole gradient of prey density.Our results show that predictability can change along an environmental gradient depending on a mean behavior.The relative predictability of the individuals with distinct mean behavior can depend on the value of the environmental gradient. In addition,this relationship can be affected by anthropogenic contaminants such as pesticides.展开更多
The Qinghai Province, situated in the northwest of China, is experiencing a continuous warming which is approximately three times more than the rate of global warming. This ongoing warming has a direct connection to v...The Qinghai Province, situated in the northwest of China, is experiencing a continuous warming which is approximately three times more than the rate of global warming. This ongoing warming has a direct connection to vegetation cover, with significant societal and economic impacts in this region. In the present study, we investigate the correlation between climate change and vegetation cover in Qinghai Province. Analysis shows that in the Qinghai Province, order of NDVI is highest in summer followed by autumn, spring and winter. By calculating the average annual and seasonal-NDVI values, it is deduced that the main type of vegetation cover in the Qinghai Province has an upward trend at the rate of 0.013/10a, 0.016/10a, 0.035/10a and 0.058/10a for annual, winter, spring and summer, respectively. While a downward trend at a rate of 0.056/10a is present in autumn-NDVI. At the 0.01% significance level, a significant positive relationship of winter-NDVI with mean winter precipitation and temperature is revealed. Mean NDVI of spring and autumn show a significant positive relationship with respective seasonal mean precipitation. However, a significant difference is present between mean summer-NDVI and mean summer precipitation. Furthermore, mean NDVI of summer and autumn has a significant negative relationship with respective seasonal mean temperature.展开更多
The aim of this study is to investigate the impact of temperature trend on glacier-mass balance, snow density, snowmelt, snow depth and runoff by using observations of nine glacier stations that covered most of the Ch...The aim of this study is to investigate the impact of temperature trend on glacier-mass balance, snow density, snowmelt, snow depth and runoff by using observations of nine glacier stations that covered most of the China over the period of 1979-2013. Trend analysis showed an increasing trend of temperature on all of the selected stations. On an average, temperature was increasing at the rate of 0.46/10a. The increasing trend of temperature showed a negative relationship with annual glacier-mass balance on most of the stations and caused a decrease in annual balance. Results of Pearson’s correlation analysis showed a highly significant negative correlation between temperature and snow density (correlation coefficient (CC = -0.661 at 0.01 significance level). There was a significant positive correlation between temperature and snowmelt (CC = 0.532 at 0.01 significance level). There was a significant negative correlation between temperature and snow depth (correlation coefficient (CC = -0.342 at 0.05 significance level). Moreover, there was a significant positive correlation between temperature and runoff (CC = 0.586 at 0.01 significance level). Increasing trend of temperature caused an increasing trend of annual snowmelt and runoff anomaly% at the rate of 24.82/10a and 9.87/10a, respectively. On the other hand, a declining trend in annual snow density and snow depth anomaly% was found at a rate of -5.32/10a and -1.93/10a, respectively. We concluded that the snow density, snowmelt and runoff are significantly sensitive to temperature in China. This contribution has provided information for further understanding of glacier variation and its influencing factors.展开更多
Phlebiopsis gigantea strains registered in the European Union as biocontrol agents against root rot in forests （four from Great Britain and two from Finland） were compared using Ward＇s method with reference to： （...Phlebiopsis gigantea strains registered in the European Union as biocontrol agents against root rot in forests （four from Great Britain and two from Finland） were compared using Ward＇s method with reference to： （l） similarity of DNA-random amplified microsatellite （RAMS） ladders, （2） cellulase and peroxidase production and （3） acceleration of dry mass wood loss in Norway spruce The activity of the enzymes was tested in the initial phase of wood decay （30 d after inoculation） and indicated as the most active isolates： VFI0 and FCl5 for cellulase and FC16 and VFI0 for peroxidase production. The assessment of loss of wood six months after inoculation indicated isolate FC 15 as the most active. P. gigantea isolates similar in terms of enzyme activity indicated different patterns ofDNA microsatellite loci. At the same time, DNA-RAMS revealed similarities in isolates with different abilities to produce enzymes. However, some similarities and differences between isolates according to wood decay were found. No plain relationships between molecular characteristics and enzyme activity of the strains tested were observed. The results differentiated activity of tested isolates and suggested benefits of selecting P. gigantea strains for commercial use basing mainly on the assessment of wood loss activity.展开更多
Effects of sublethal piperonyl butoxide （PB） on parasitization of Bemisia tabaci （Gennadius） （Hemiptera： Aleyrodidae） by Encarsia bimaculata Heraty et Polaszek （Hymenoptera： Aphelinidae） were evaluated both ...Effects of sublethal piperonyl butoxide （PB） on parasitization of Bemisia tabaci （Gennadius） （Hemiptera： Aleyrodidae） by Encarsia bimaculata Heraty et Polaszek （Hymenoptera： Aphelinidae） were evaluated both in cage and greenhouse experiments. When first, second and third instar B. tabaci nymphs were treated with PB, all but the first instar were significantly prolonged. Data indicated that sublethal PB could improve E. bimaculata parasitism rates without influencing parasitoid eclosion rates. Prolonged development increased rates of parasitism by E. bimaculata, from 17.6% to 24.7% in cages, presumably by increasing the duration of host exposure. Sublethal PB combined with E. bimaculata as an integrated approach to control B. tabaci was evaluated using life table parameters under greenhouse conditions. Indices of population trend （I） calculated from life tables were estimated at 4.6 for B. tabaci exposed to PB and parasitoids compared to 14.1 with parasitoids alone and 23.5 in un- treated controls. The results showed that after PB was sprayed and parasitoids introduced, development ofB. tabaci was delayed and the peak of each stage was postponed. The older nymphal stage had highest mortality, primarily due to mortality caused by parasitism by E. bimaculata.展开更多
Novel interactions between introduced oaks and their natural enemies across different continents provide an opportunity to test the enemy release hypothesis(ERH)at local and global scales.Based on the ERH,we assessed ...Novel interactions between introduced oaks and their natural enemies across different continents provide an opportunity to test the enemy release hypothesis(ERH)at local and global scales.Based on the ERH,we assessed the impacts of native seed-feeding insects on introduced and native oaks within and among continents.We combined a common-garden experiment in China and biogeographic literature surveys to measure seed predation by insects and the proportion of acorn embryos surviving after insect infestation among 4 oak species with different geographical origins:Quercus mongolica origin from China,Q.robur and Q.petraea from Europe,and Q.rubra from North America.Mostly supporting the ERH,oaks in introduced continents escaped seed predation compared to those in native continents and compared to other native oaks in introduced continents.Common-garden comparisons showed that total acorn infestation rate of introduced Q.rubra(section Lobatae)was considerably lower than that of native oaks(section Quercus)in China and Europe,likely because of the differences in seed traits associated with different oak sections.Literature surveys showed that seed predation of introduced oaks was lower in the introduced continent than in the native continent.Embryo survival was higher in introduced Q.rubra than native oaks in China and Poland.However,insect seed predation of recently introduced Q.rubra in China was similar to that in Europe,which is not consistent with the ERH.Our results suggest that reduced acorn attack by native insects and higher embryo survival after acorn damage could increase the establishment success or invasion risk of introduced oaks in non-native continents.展开更多
基金funded by the National Research Foundation of Korea(No.2017R1D1A1B06035179)the Seoul Green Environment Center(SGEC)support from the International Atomic Energy Agency(IAEA),Vienna,Austria,through a Coordinated Research Project(No.CRP D150.16)。
文摘Soil heterotrophic respiration and its temperature sensitivity are affected by various climatic and environmental factors.However,little is known about the combined effects of concurrent climatic and environmental changes,such as climatic warming,changing precipitation regimes,and increasing nitrogen(N)deposition.Therefore,in this study,we investigated the individual and combined effects of warming,wetting,and N addition on soil heterotrophic respiration and temperature sensitivity.We incubated soils collected from a temperate forest in South Korea for 60 d at two temperature levels(15 and 20℃,representing the annual mean temperature of the study site and 5℃warming,respectively),three moisture levels(10%,28%,and 50%water-filled pore space(WFPS),representing dry,moist,and wet conditions,respectively),and two N levels(without N and with N addition equivalent to 50 kg N ha^(-1)year^(-1)).On day 30,soils were distributed across five different temperatures(10,15,20,25,and 30℃)for 24 h to determine short-term changes in temperature sensitivity(Q_(10),change in respiration with 10℃increase in temperature)of soil heterotrophic respiration.After completing the incubation on day 60,we measured substrate-induced respiration(SIR)by adding six labile substrates to the three types of treatments.Wetting treatment(increase from 28%to 50%WFPS)reduced SIR by 40.8%(3.77 to 2.23μg CO_(2)-C g^(-1)h^(-1)),but warming(increase from 15 to 20℃)and N addition increased SIR by 47.7%(3.77 to 5.57μg CO_(2)-C g^(-1)h^(-1))and 42.0%(3.77 to 5.35μg CO_(2)-C g^(-1)h^(-1)),respectively.A combination of any two treatments did not affect SIR,but the combination of three treatments reduced SIR by 42.4%(3.70 to 2.20μg CO_(2)-C g^(-1)h^(-1)).Wetting treatment increased Q_(10)by 25.0%(2.4 to 3.0).However,warming and N addition reduced Q_(10)by 37.5%(2.4 to 1.5)and 16.7%(2.4 to 2.0),respectively.Warming coupled with wetting did not significantly change Q_(10),while warming coupled with N addition reduced Q_(10)by 33.3%(2.4 to 1.6).The combination of three treatments increased Q_(10)by 12.5%(2.4 to 2.7).Our results demonstrated that among the three factors,soil moisture is the most important one controlling SIR and Q_(10).The results suggest that the effect of warming on SIR and Q_(10)can be modified significantly by rainfall variability and elevated N availability.Therefore,this study emphasizes that concurrent climatic and environmental changes,such as increasing rainfall variability and N deposition,should be considered when predicting changes induced by warming in soil respiration and its temperature sensitivity.
基金the National Natural Science Foundation of China(No.31670494).
文摘The eff ect of seasons on the soil microbiome in a Larix gmelinii forest of Mohe,China,where winter temperatures are generally below−40°C,was evaluated with metagenomics analysis.Taxonomic profi ling using sequencing information revealed that Proteobacteria,Actinobacteria,Acidobacteria and Verrucomicrobia were the dominant phyla in spring,summer,and fall,as were Bradyrhizobium,Chthoniobacter,Streptomyces,Acid Candidatus Koribacter at the genus level.Some species that were abundant in spring and fall greatly diminished in abundance in summer.Clusters of orthologous groups(COG)of proteins,carbohydrate-active enzymes(CAZy),Kyoto Encyclopedia of Genes and Genomes(KEGG)and NCBI databases were used to elucidate the function of diverse proteins and metabolites of the microbial community of L.gmelinii forest.COG analysis showed that fewer genes were detected in spring than in fall and summer,indicating that many soil microbes in the L.gmelinii forest were not tolerant to cold.Based on KEGG analysis,some pathways in the soil microbes were activated in spring and autumn and deactivated in summer.CAZy analysis revealed that most CAZy were more active in summer than in spring or autumn and were severely inhibited in the spring.Many functional pathways,proteins,and CAZy involved in the community changes were concerned with cold or heat resistance.Therefore,the soil in the L.gmelinii forest can be a valuable resource for further research on heat and cold tolerance of soil microbes.
基金supported by the Science and Technology Department of Zhejiang Province, China (Grant Nos. 2022C02022 and 2023C02020)。
文摘Rice husk biochar inoculated with Bacillus megaterium(BM)(referred to as BM-inoculated biochar, BMB) and uninoculated rice husk biochar(RHB) were added to soil at two rates(0.5%, as BMB1 and RHB1, respectively, and 1.0%, as BMB2 and RHB2, respectively) in an incubation experiment to comprehensively evaluate their effects on basic soil properties, phosphorus(P) fractions, bacterial community composition, and P-cycling genes.
基金financed by the Ministry of Science and Higher Education, Republic of Poland
文摘We investigated the relationships between dehydrogenase activity and the physicochemical properties of mountain soils over three and five years from Norway spruce(Picea abies L. Karst) logging residue spot burning and the occurrence of epigeic carabid beetles. Six study sites were utilised, including18 study plots(nine plots in a mixed coniferous mountain forest site and nine plots in a mixed broadleaf mountain forest site), with five replicate pitfall traps at each site located in southern Poland.Soil samples from the organic horizon were taken for p H, organic carbon, nitrogen, base cation content,acidity and dehydrogenase activity determination.Carabid beetles were monitored in weekly intervals during the period of July to August 2016. The burning of logging residues led to modified soil properties,especially the dehydrogenase activity. In all the tested variants, the activity was higher in soil samples after the burning in comparison to the control variants. We show no positive correlation between dehydrogenase activity and the number of carabid specimens. The preferences of dominant predatory hygrophilous carabids to acid habitats with weakly decomposed organic matter were proven. Simultaneously, the soil organic matter content was positively related to the carabid abundance. The significant impact of forest site conditions and the date of logging residue burning on the number of caught specimens were confirmed. In contrast, no relationships between the species richness, species diversity, mean individual biomass and spot burning effect were found. This work supports the recommendation of spruce fine woody debris utilisation by spot burning on mountain regions with rich habitats presenting moderate wet conditions and small land falls.
基金supported by the Ministry of Science and Higher Education of the Republic of Poland。
文摘Background: Fires have a fundamental impact on phytocoenoses and, depending on the size of the fire, can have a positive or negative effect. The role of fires in the formation of the species composition of plants, restoration of stands and changes in soil properties is well studied. However, the long-term relationship between forest management methods, soil properties and epigeic entomofauna assemblages in post-fire areas is still not clear. The effects of Scots pine stand management methods on biochemical soil properties and ground beetle assemblages in the largest post-fire area in Central Europe after the second World were investigated. The study was conducted in the Rudy Raciborskie Forest district in southern Poland. The soil properties and epigeic beetle community structure were analysed. The research covered areas with natural and artificial pine regeneration, which were subjected to various care treatments.Results: The tendency for higher accumulations of organic matter in the soil of stands that underwent natural regeneration was proven. The stimulating role of soil organic carbon on the activity of dehydrogenases in the soil of naturally renewed areas with silvicultural treatment(NRAT) was noted. Regardless of the manner of stand regeneration, the activity of β-glucosidase was higher in the areas in which breeding treatments were practised.Furthermore, managed forest stands presented a higher abundance of carabid beetles than stands without treatment practices. Thirteen epigeic beetle species from the families Geotrupidae, Carabidae, Curculionidae,Cerambycidae and Silphidae were captured, with beetles from the first two families being the most numerous. Rare epigeal carabid species in the fauna of Poland and Europe, such as Carabus glabratus(Paykull) and Carabus auronitens Fabr., found appropriate habitat conditions for survival in the post-fire areas. Compared with the other areas, in the NRAT area, there were better stand and soil properties and more features conducive to epigeic entomofaunal occurrences. The highest post-fire content of polycyclic aromatic hydrocarbons was recorded in the soils of the sites that underwent artificial regeneration. The results suggest that preparing the soil before the introduction of new vegetation affects the amount of aromatic hydrocarbons(PAHs).Conclusions: The better performance of the NRAT stand draws attention to the positive aspects of the use of natural regeneration, both from ecological and economic perspectives. The effects of forest management on the amount of soil organic matter after fires have been proven. The natural regeneration of stands was conducive to the accumulation of organic matter. The enzymatic activity of soils is influenced by the renewal method and forest management strategy. The NRAT area was characterized by the highest number of carabid species.
基金The present study was supported by the Guangzhou Collaborative Innovation Center on Science-Tech of Ecology and Landscape(202206010058)the National Natural Science Foundation of China(32000327).
文摘The genus Diomus Mulsant,1850(Coleoptera:Coccinellidae:Diomini)from China is herein revised.Five species of Diomus are occurring in the Chinese fauna to date,including a new species from the Dafushan Mountains Forest Park,Guangzhou,Guangdong,namely D.dafushanensis Bi,Peng&Chen,sp.nov.Nomenclatural history,diagnosis,illustrations and distribution were provided for each species.A key to the native species of Diomus from China is also presented.
文摘A novel embedded sensor network records changes in key climatic-environmental variables over a range of altitude in the BaekduDaegan Mountain （BDM） of Gangwon Province in Korea, a protected mountain region with unique biodiversity undergoing climate change research. The investigated area is subdivided into three horizontal north-south study areas. Three variables, temperature （T, °C）, relative humidity （RH, %）, and light intensity （LI, lumens m-2, or lux, lx）, have been continuously measured at hourly intervals from June, 2olo to September, 2011 using HOBO H8 devices at lO fixed study sites. These hourly observations are aggregated to monthly, seasonal and annual mean values, and results are summarized to inaugurate a long-term climate change investigation. A region wide T difference in accordance with altitude, or lapse rate, over the interval is calculated as o.4°C l00 m-1. T lapse rates change seasonally, with winter lapse rates being greater than those of summer. RH is elevated in summer compared to other seasons. LI within forestland is lower during summer and higher during other seasons. The obtained results could closely relate to the vegetation type and structure and the terrain state since data loggers were located in forestland.
基金supported by Ministry of Agriculture of the Czech Republic in grant[QK1920433].“Influence of protective measuresagainst the populations of bark beetles according to population density”。
文摘The large larch beetle,Ips cembrae,is a significant pest causing the death of larch.In 2020,the attack density of I.cembrae on larch trap trees and standing trees was evaluated using sample sections placed along the trunk.As a defensive measure against I.cembrae,trap trees were highly effective in both spring and summer.The attack density increased with increasing trap tree surface area/volume.Galleries were established evenly throughout the entire trunk including the thin upper portion.When the number of trap trees was low and their capacity full,a continual aggregation of adults occurred due to pheromone communication,leading to attacks on healthy standing trees in the immediate vicinity.It was found that I.cembrae attacked standing trees from the trunk base,with a continual colonization of the stem up to 70%of the tree height in a time-differentiated progression of development stages.The attack density of I.cembrae on standing trees was up to 40%lower than on the trap trees.
基金funded partly by the Fundamental Research Funds of the Chinese Central Universities(grant no.2572017AA18)Chinese Central Financial Forest Science and Technology Extension Demonstration Fund Project(grant no.JLT[2016]13)。
文摘To study the effect of manganese exposure on the herbivorous insect Lymantria dispar asiatica,fourthinstar larvae were fed a MnCl_(2)-amended diet(LdMn)for 84 h(0.40 mmol MnCl_(2)/g diet).Larvae were weighed before and after the diet administration to assess larval gain in mass under manganese exposure.The whole bodies of half of the survivors were ground in liquid nitrogen for measuring enzyme activities and total antioxidant capacity(T-AOC).The intestinal tracts of the remaining survivors were collected and immediately frozen in liquid nitrogen for 16S rDNA sequencing of gut microbiota.Larvae under manganese stress lost significant mass(p<0.05).The activities of digestive and antioxidant enzymes and T-AOC,but not trehalase and polyphenol oxidase,were significantly higher after Mn exposure,(p<0.05).A Venn diagram illustrated that the gut microbial OTU composition in the larvae also changed.Community pies and correlation heatmaps also showed different relative abundances of gut microbes.In other words,species quantity and relative abundance of gut microbes agreed with PCoA visualization and indicated that the gut microbial community in L.dispar asiatica larvae differed significantly between control and LdMn.Functional classification also suggested that exposure to manganese stress significantly decreased gut microbial coenzyme transport and metabolism in L.dispar asiatica larvae.These results further our understanding about stress response of L.dispar asiatica larvae.
文摘The aim of this research paper is to investigate the land cover changes in Sudan during the period 2001-2013 by using the MODIS data and to identify climatic factors influencing the land cover. SPSS v 17 software was used to investigate the correlation of climatic factors with vegetation cover;also ArcGIS v 10.2 software was used to analyze the NDVI data. The results indicate that the monthly average time scale, NDVI value curve distribution during the year, July to October as the center to both sides of decreasing vegetation cover in other months. In the spatial distribution of mean NDVI in Sudan, a high value was found in the southern part. On the other hand, a low value of vegetation cover was found in northern part. NDVI spaces mean presenting features values: autumn followed by summer then winter. By calculation of average annual and seasonal-NDVI values, it was deduced that the main vegetation cover type was increasing in winter and summer seasons at the rates of 0.014/10a and 0.008/10a, respectively. While winter-NDVI was decreasing the rate of 0.001/10a and 0.026/10a in autumn and on the annual scale, respectively. Annual NDVI showed a significant degradation (area = 12705.7 km2, 0.5% of total area) in the middle and eastern parts and significant improvement (area = 22485.4 km2, 0.9 % of the total area) in the southern part of the country due to the increase in precipitation and decrease in temperature. Mean summer and autumn-NDVI showed a significant difference 0.01% significance level with mean summer and autumn precipitation (correlation coefficients = 0.955 and 0.953, respectively). While there was a significantly negative relationship between mean summer and autumn-NDVI with mean summer and autumn temperature at 0.01% significance level (correlation coefficients = −0.270 and −0.820, respectively).
文摘Land use activities (LUA) have a significant impact on the level and situation of vegetation characteristics and in turn affect human population as they are considered as the main global environmental changes. This study analyzed land use patterns in three different locations in Khartoum, Sudan: banks of River Nile, Blue and White Nile. The main objective of the present study were 1) to assess the changes in land use and their impact on vegetation cover and sustainable livelihoods of the population, and 2) to identify the factors behind land use changes along the Banks of Niles, Khartoum State. The study data used were field survey (questionnaire) which revealed the existence of five types of land use patterns: roads, human settlements, agricultural and plantations farms, and industrial of brick-kilns making and investment areas. The primary data were collected through social survey (questionnaire) as face-to-face interviews with local communities in the study area and by observations. The secondary records during the field survey were collected from the Ministry of Agriculture and Forestry, and the Forest National Corporation (FNC) documents, scientific papers and annual reports. SPSS was used to analyze the data acquired from questionnaires. Results showed that agricultural land, and industrial and residential areas increased while forests and bare lands decreased as a result of changes imposed by the government and local population with consequent land degradation in terms of environmental value and productivity. Interestingly, it was found that the impact of land use on vegetation cover and livelihood of the population was very complex and dynamic and that the main influencing factors in this process were climate fluctuations and human illegal interference. For instance, vast areas in west bank of White Nile were changed from agriculture to residence and investment. In conclusion, land use requires a clear plan for optimum utilization. Various human activities are behind these changes, which have led to deterioration of forest cover and loss of the source of income of local population. Because of such alarming changes, decision makers should initiate efficient plans and management of forests to minimize changes in land cover, especially in arid and semi-arid areas. We recommend that a sound land use plan should be revised often to ensure rehabilitation, reduce vulnerability to desertification and halt the encroachment by construction of facilities and buildings at the expense of environmental issues.
文摘The aims of this research were to investigate the impacts of climate variations on land use policies, food security and vegetation cover in Gadarif State (eastern Sudan) during 1961 to 2013. Analysis of precipitation and temperature time series revealed that the annual precipitation was decreasing while the temperature was increased in the study area. Precipitation was decreasing at a rate of −50.3 mm/10a, while the temperature was increasing at a rate of 0.02°C/10a. The result of both SPEI and SPI showed that the Gadarif State has been changed to a high frequency of drought during 1961-2013. Sorghum yield showed a significant positive relationship with precipitation during July and October (CC = 0.364 and 0.321, respectively), moreover, a significant positive relationship between Sesame yield and precipitation was observed during July (CC = 0.335). A significant negative relationship between Sorghum yield and mean temperature was observed during the rainy season (July to October) with CC = −0.278. The yield productivity of Sorghum and Sesame had decreased significantly (from more than 800 kg/ha in the 1960s to less than 200 kg/ha in 2000s for Sorghum, while 500 kg/ha in 1960s to 100 kg/ha in 2000s for Sesame). The Mechanized Rain-fed Agriculture (MRA) area of Sorghum and Sesame in the Gadarif State had been increased from 1,058,241 ha to 2,799,655 ha during 1961 to 2013. Thus, we ultimately suggest that in the Gadarif State, policy makers must strive for an increase in yield per unit area by using sufficient fertilizers along with the gradual increment in tendencies of grain production through expansion of the cultivated area.
基金supported by the National Natural Science Foundation of China(31501886)
文摘General characteristics of Globicornis Latreille and a key of known subgenera of the genus are given. The new species G.（Globicornis） yushuensis sp. nov. from China（Qinghai Province） is described and illustrated.
文摘Background:Nesting trees and habitat represent the key factor underpinning stand selection by forest-dwelling birds.While two large European species–the black stork(Ciconia nigra L.)and white-tailed eagle(Haliaaetus albicilla L.)–are known to require old,large trees for nesting,we sought to investigate further by comparing species requirements at the levels of the nesting tree,nesting stand,and landscape.This entailed a detailed examination of forest features within circles of radius 15 m surrounding 16 and 19 trees holding the nests of storks and eagles respectively.The same parameters were also checked in the vicinity of 50 randomly-selected mature trees.Results:Our results indicate different nesting preferences,with the eagles entirely confining themselves to Scots pine(Pinus sylvestris L.)–a species also chosen by black storks,which nevertheless regularly favour pedunculate oak(Quercus robur L.).Both species select trees of greater girth than the random ones,but white-tailed eagles choose to nest in the vicinity of patches of mature old stands with a loose canopy,to the extent that nesting trees and surrounding trees are of similar ages.In contrast,black storks prefer“veteran”trees with low-set crowns that are much older than any others in their vicinity.Nesting trees of the eagles are away from roads and close to lakes,while black storks do not avoid roads.Conclusions:As the ages of nesting trees of both species are greater than ages at final cutting in this region’s managed forest,silvicultural measures will need to be adjusted,with small patches of forest spared,or larger areas as“islands”of old-growth.Likewise,as tending and thinning are engaged in,certain trees with horizontal branches will need to remain,with relict trees also left untouched.As it happens,all of these recommendations are anyway key elements of close-to nature silviculture and multifunctional forestry.
文摘Behavioral predictability,i.e.,short-term intra-individual variability under relatively constant environmental conditions,has only recently begun to gain attention.It is unknown,however,whether predictability of individuals with distinct mean behavior changes differently as a response to ecological factors such as resource availability.Moreover,the response might be affected by anthropogenic contaminants that are ubiquitous in the environment and that can affect animals' variability in behavior.Here,we investigated the relationship between mean predatory activity and predictability in predatory activity along a prey density gradient in the lynx spider Oxyopes lineatipes.We further examined how this relationship is influenced by insecticides,azadirachtin,and a plant extract from Embelia ribes.We found that all studied variables affected the predictability.In the control and Embelia treatments,that did not differ significantly,the predictability decreased with increasing prey density in a mean behavior-specific way.Individuals with low mean predatory activity were relatively less predictable than were those with high activity from low to moderate prey densities but more predictable at high prey densities.Azadirachtin altered this pattern and the individuals with low predatory activity were less predictable than were those with high predatory activity along the whole gradient of prey density.Our results show that predictability can change along an environmental gradient depending on a mean behavior.The relative predictability of the individuals with distinct mean behavior can depend on the value of the environmental gradient. In addition,this relationship can be affected by anthropogenic contaminants such as pesticides.
文摘The Qinghai Province, situated in the northwest of China, is experiencing a continuous warming which is approximately three times more than the rate of global warming. This ongoing warming has a direct connection to vegetation cover, with significant societal and economic impacts in this region. In the present study, we investigate the correlation between climate change and vegetation cover in Qinghai Province. Analysis shows that in the Qinghai Province, order of NDVI is highest in summer followed by autumn, spring and winter. By calculating the average annual and seasonal-NDVI values, it is deduced that the main type of vegetation cover in the Qinghai Province has an upward trend at the rate of 0.013/10a, 0.016/10a, 0.035/10a and 0.058/10a for annual, winter, spring and summer, respectively. While a downward trend at a rate of 0.056/10a is present in autumn-NDVI. At the 0.01% significance level, a significant positive relationship of winter-NDVI with mean winter precipitation and temperature is revealed. Mean NDVI of spring and autumn show a significant positive relationship with respective seasonal mean precipitation. However, a significant difference is present between mean summer-NDVI and mean summer precipitation. Furthermore, mean NDVI of summer and autumn has a significant negative relationship with respective seasonal mean temperature.
文摘The aim of this study is to investigate the impact of temperature trend on glacier-mass balance, snow density, snowmelt, snow depth and runoff by using observations of nine glacier stations that covered most of the China over the period of 1979-2013. Trend analysis showed an increasing trend of temperature on all of the selected stations. On an average, temperature was increasing at the rate of 0.46/10a. The increasing trend of temperature showed a negative relationship with annual glacier-mass balance on most of the stations and caused a decrease in annual balance. Results of Pearson’s correlation analysis showed a highly significant negative correlation between temperature and snow density (correlation coefficient (CC = -0.661 at 0.01 significance level). There was a significant positive correlation between temperature and snowmelt (CC = 0.532 at 0.01 significance level). There was a significant negative correlation between temperature and snow depth (correlation coefficient (CC = -0.342 at 0.05 significance level). Moreover, there was a significant positive correlation between temperature and runoff (CC = 0.586 at 0.01 significance level). Increasing trend of temperature caused an increasing trend of annual snowmelt and runoff anomaly% at the rate of 24.82/10a and 9.87/10a, respectively. On the other hand, a declining trend in annual snow density and snow depth anomaly% was found at a rate of -5.32/10a and -1.93/10a, respectively. We concluded that the snow density, snowmelt and runoff are significantly sensitive to temperature in China. This contribution has provided information for further understanding of glacier variation and its influencing factors.
文摘Phlebiopsis gigantea strains registered in the European Union as biocontrol agents against root rot in forests （four from Great Britain and two from Finland） were compared using Ward＇s method with reference to： （l） similarity of DNA-random amplified microsatellite （RAMS） ladders, （2） cellulase and peroxidase production and （3） acceleration of dry mass wood loss in Norway spruce The activity of the enzymes was tested in the initial phase of wood decay （30 d after inoculation） and indicated as the most active isolates： VFI0 and FCl5 for cellulase and FC16 and VFI0 for peroxidase production. The assessment of loss of wood six months after inoculation indicated isolate FC 15 as the most active. P. gigantea isolates similar in terms of enzyme activity indicated different patterns ofDNA microsatellite loci. At the same time, DNA-RAMS revealed similarities in isolates with different abilities to produce enzymes. However, some similarities and differences between isolates according to wood decay were found. No plain relationships between molecular characteristics and enzyme activity of the strains tested were observed. The results differentiated activity of tested isolates and suggested benefits of selecting P. gigantea strains for commercial use basing mainly on the assessment of wood loss activity.
基金Acknowledgments This research was supported by the China National Natural Science Foundation （30400292, 31071743）, National Basic Research Program of China （973 project 2006CB 102005, 948 project 2011 4 6 1） and Na- tional Department Public Benefit Research Foundation （201003065）.
文摘Effects of sublethal piperonyl butoxide （PB） on parasitization of Bemisia tabaci （Gennadius） （Hemiptera： Aleyrodidae） by Encarsia bimaculata Heraty et Polaszek （Hymenoptera： Aphelinidae） were evaluated both in cage and greenhouse experiments. When first, second and third instar B. tabaci nymphs were treated with PB, all but the first instar were significantly prolonged. Data indicated that sublethal PB could improve E. bimaculata parasitism rates without influencing parasitoid eclosion rates. Prolonged development increased rates of parasitism by E. bimaculata, from 17.6% to 24.7% in cages, presumably by increasing the duration of host exposure. Sublethal PB combined with E. bimaculata as an integrated approach to control B. tabaci was evaluated using life table parameters under greenhouse conditions. Indices of population trend （I） calculated from life tables were estimated at 4.6 for B. tabaci exposed to PB and parasitoids compared to 14.1 with parasitoids alone and 23.5 in un- treated controls. The results showed that after PB was sprayed and parasitoids introduced, development ofB. tabaci was delayed and the peak of each stage was postponed. The older nymphal stage had highest mortality, primarily due to mortality caused by parasitism by E. bimaculata.
基金This research was supported by the National Natural Science Foundation of China(31770565)the National Key Research and Development Program of China(2017YFC0503802)the State Key Laboratory of Integrated Management of Pest Insects and Rodents(IPM1911).
文摘Novel interactions between introduced oaks and their natural enemies across different continents provide an opportunity to test the enemy release hypothesis(ERH)at local and global scales.Based on the ERH,we assessed the impacts of native seed-feeding insects on introduced and native oaks within and among continents.We combined a common-garden experiment in China and biogeographic literature surveys to measure seed predation by insects and the proportion of acorn embryos surviving after insect infestation among 4 oak species with different geographical origins:Quercus mongolica origin from China,Q.robur and Q.petraea from Europe,and Q.rubra from North America.Mostly supporting the ERH,oaks in introduced continents escaped seed predation compared to those in native continents and compared to other native oaks in introduced continents.Common-garden comparisons showed that total acorn infestation rate of introduced Q.rubra(section Lobatae)was considerably lower than that of native oaks(section Quercus)in China and Europe,likely because of the differences in seed traits associated with different oak sections.Literature surveys showed that seed predation of introduced oaks was lower in the introduced continent than in the native continent.Embryo survival was higher in introduced Q.rubra than native oaks in China and Poland.However,insect seed predation of recently introduced Q.rubra in China was similar to that in Europe,which is not consistent with the ERH.Our results suggest that reduced acorn attack by native insects and higher embryo survival after acorn damage could increase the establishment success or invasion risk of introduced oaks in non-native continents.
