The research was carried out on the territory of the Karelian Isthmus of the Leningrad Region using Sentinel-2B images and data from a network of ground sample plots. The ground sample plots are located in the studied...The research was carried out on the territory of the Karelian Isthmus of the Leningrad Region using Sentinel-2B images and data from a network of ground sample plots. The ground sample plots are located in the studied territory mainly in a regular manner, laid and surveyed according to the ICP-Forests methodology with some additions. The total area of the sample plots is a small part of the entire study area. One of the objectives of the study was to determine the possibility of using the k-NN (nearest neighbor method) to assess the state of forests throughout the whole studied territory by joint statistical processing of data from ground sample plots and Sentinel-2B imagery. The data of the ground-based sample plots were divided into 2 equal parts, one for the application of the k-NN method, the second for checking the results of the method application. The systematic error in determining the mean damage class of the tree stands on sample plots by the k-NN method turned out to be zero, the random error is equal to one point. These results offer a possibility to determine the state of the forest in the entire study area. The second objective of the study was to examine the possibility of using the short-wave vegetation index (SWVI) to assess the state of forests. As a result, a close statistically reliable dependence of the average score of the state of plantations and the value of the SWVI index was established, which makes it possible to use the established relationship to determine the state of forests throughout the studied territory. The joint use and statistical processing of remotely sensed data and ground-based test areas by the two studied methods make it possible to assess the state of forests throughout the large studied area within the image. The results obtained can be used to monitor the state of forests in large areas and design appropriate forestry protective measures.展开更多
The article considers the impact of forestry machines on the soil of the cutting areas and presents the results of the impact of harvesters of different classes(middlesmall,middle and heavy)and configurations of wheel...The article considers the impact of forestry machines on the soil of the cutting areas and presents the results of the impact of harvesters of different classes(middlesmall,middle and heavy)and configurations of wheeled equipment and additional equipment on the soil of the cutting areas in the conditions of Kronoberg County(South of Sweden).Methods to reduce negative impact of wheeled harvesters on the soil of forests are proposed.The aim of the research is to assess the effect of the structural parameters of the wheel harvesters of different class on the soil of the cutting areas.Wheeled harvesters were loaded with 60 kN force.The results of experimental studies of the impact of wheeled harvesters on the forest soil are presented.Recommendations on the possibility of testing the results of research in the conditions of the rental base of the Western part of the North-Western Federal District of the Russian Federation are given.展开更多
In this paper,the stability of the results of ultrasonic wood surface modification after long-term storage,including macroscopic properties and microstructure of specimens,was investigated.Specimens of aspen wood(Popu...In this paper,the stability of the results of ultrasonic wood surface modification after long-term storage,including macroscopic properties and microstructure of specimens,was investigated.Specimens of aspen wood(Populus tremula)were processed by the developed ultrasonic method of wood surface modification in three different treatment modes and the surface hardness of the specimens was evaluated after processing and after storing the specimens for more than 5 years since long-term stability is an important factor for the use of ultrasonically modified sawn timber as construction and finishing materials.The obtained results of surface hardness measurements by the Leeb method showed that the decrease in hardness after long-term storage is approximately 6.6%for the lowest degree of treatment and approximately 3.4%and 2.4%for medium and high degrees of treatment,taking into account the fact of the average increase in surface hardness approximately 2–4 times,this decrease is insignificant.The internal structure of the specimens after storage was studied by scanning electron microscope(SEM),and deformations of the wood surface layer without damage or rupture were analyzed.The derived stable results confirm the potential of the ultrasonic method for wood surface modification.展开更多
To better promote forest resource management and strengthen the development of forest carbon sink marketization, this paper studied the accounting of forest carbon sinks from 2003 to 2008 based on a system of national...To better promote forest resource management and strengthen the development of forest carbon sink marketization, this paper studied the accounting of forest carbon sinks from 2003 to 2008 based on a system of national accounts （SNA） and data from the latest forest resources inventory in China. The study calculated the value of forest carbon stocks at a total of RMB 817.13 × 10^9 yuan in 2003 and RMB 839.93×10^9 yuan in 2008, with an average annual increase of 0.55 % from an increase in physical carbon sinks. The total value of forest carbon sinks in 2003 and 2008 was RMB 26.73×10^9 yuan and RMB 29.77×10^9 yuan, respectively, with an average annual growth of 2.18 %. From 2003 to 2008, both stock and flow value of forest carbon sinks increased, but the total net flow value of carbon sinks decreased. The growth rate for the environmentally adjusted Gross Domestic Product （eaGDP） for China＇s forest carbon sinks was 17.23 %, outstripping the average growth rate of 9.5 % for the GDP during the same period. The study alsoindicates that China＇s forest carbon sinks affects the GDP in the range of 0.25-0.26 %, and its economic potential is not relatively huge.展开更多
Many studies have shown soil degradation after the conversion of native forests to exotic Eucalyptus plantations. However, few studies have investigated the long-term impacts of short-rotation forestry practices on so...Many studies have shown soil degradation after the conversion of native forests to exotic Eucalyptus plantations. However, few studies have investigated the long-term impacts of short-rotation forestry practices on soil microorganisms. The impacts of Eucalyptus successive rotations on soil microbial communities were evaluated by comparing phospholipid fatty acid （PLFA） abundances, compositions, and enzyme activities of native Pinus massoniana plantations and adjacent 1st, 2nd, 3rd, 4th generation Eucalyptus plantations. The conversion from P. massoniana to Eucalyptus plantations significantly decreased soil microbial community size and enzyme activities, and increased microbial physiological stress. However, the PLFA abundances formed ＂U＂ shaped quadratic functions with Eucalyptus plantation age. Alternatively, physiological stress biomarkers, the ratios of monounsaturated to saturated fatty acid and Gram＋ to Gram- bacteria, formed ＂∩＂ shaped quadratic functions, and the ratio of cy17：0 to 16： 1ω7c decreased with plantation age. The activities of phenol oxidase, peroxidase, and acid phosphatase increased with Eucalyptus plantation age, while the cellobiobydrolase activity formed ＂U＂ shaped quadratic functions. Soil N：P, alkaline hydrolytic nitrogen, soil organic carbon, and understory cover largely explained the variation in PLFA profiles while soil N：P, alkaline hydrolytic nitrogen, and understory cover explained most of the variability in enzyme activity. In conclusion, soil microbial structure and function under Eucalyptus plantations were strongly impacted by plantation age. Most of the changes could be explained by altered soil resource availability and understory cover associated with successive planting of Eucalyptus. Our results highlight the importance of plantation age for assessing the impacts of plantation conversion as well as the importance of reducing disturbance for plantation management.展开更多
A total of 128 Simao pine trees （Pinus kesiya var. langbianensis） from three regions of Pu＇er City, Yunnan Province, People＇s Republic of China, were destructively sampled to obtain tree aboveground biomass （AGB...A total of 128 Simao pine trees （Pinus kesiya var. langbianensis） from three regions of Pu＇er City, Yunnan Province, People＇s Republic of China, were destructively sampled to obtain tree aboveground biomass （AGB）. Tree variables such as diameter at breast height and total height, and topographical factors such as altitude, aspect of slope, and degree of slope were recorded. We considered the region and site quality classes as the ran- dom-effects, and the topographic variables as the fixed- effects. We fitted a total of eight models as follows： least- squares nonlinear models （BM）, least-squares nonlinear models with the topographic factors （BMT）, nonlinear mixed-effects models with region as single random-effects （NLME-RE）, nonlinear mixed-effects models with site as single random-effects （NLME-SE）, nonlinear mixed-ef- fects models with the two-level nested region and site random-effects （TLNLME）, NLME-RE with the fixed-ef- fects of topographic factors （NLMET-RE）, NLME-SE with the fixed-effects of topographic factors （NLMET-SE）, and TLNLME with the fixed-effects of topographic factors （TLNLMET）. The eight models were compared by modelfitting and prediction statistics. The results showed： model fitting was improved by considering random-effects of region or site, or both. The models with the fixed-effects of topographic factors had better model fitting. According to AIC and BIC, the model fitting was ranked as TLNLME 〉 NLMET-RE 〉 NLME-RE.〉 NLMET-SE 〉 TLNLMET 〉 NLME-SE 〉 BMT 〉 BM. The differences among these models for model prediction were small. The model pre- diction was ranked as TLNLME 〉 NLME-RE 〉 NLME- SE 〉 NLMET-RE 〉 NLMET-SE 〉 TLNLMET 〉 BMT 〉 BM. However, all eight models had relatively high prediction precision （〉90 %）. Thus, the best model should be chosen based on the available data when using the model to predict individual tree AGB.展开更多
In order to investigate the effect of invastion by pine wood nematode(PWN), this study analyzed several functional indices, i.e., the increment in DBH and stand volume and biomass, in the damaged stands with various m...In order to investigate the effect of invastion by pine wood nematode(PWN), this study analyzed several functional indices, i.e., the increment in DBH and stand volume and biomass, in the damaged stands with various mixed percentages of Pinus massoniana and P. thunbergii and with different levels of damage. According to the results of rate of change in increment of DBH and stand volume, the forest ecosystem resistance against PWN increased with a reduction in the mixed ratio of pine. The resistance was highest with a mixed percentage of 50%. The invasion of PWN changed the corresponding relationship of increment between DBH and stand volume(pure stands > 7:3 conifer and broadleaf > 6:4 conifer and broadleaf > 5:5 conifer and broadleaf) among the P. thunbergii stands when there is no damage, but for P. massoniana stands this phenomenon did not occur. For the increment rate of DBH and stand volume, this significant change in P. thunbergii forest indicates that the resistance of pure P. thunbergii forest was higher than that of P. massoniana. The invasion of PWN accelerates the succession from pure stands to mixed stands and then to the broadleaf evergreen stands.展开更多
Nitraria tangutorum nebkhas are widely distributed in the arid and semi-arid desert areas of China.The formation and development of N.tangutorum nebkhas are the result of the interaction between vegetation and the sur...Nitraria tangutorum nebkhas are widely distributed in the arid and semi-arid desert areas of China.The formation and development of N.tangutorum nebkhas are the result of the interaction between vegetation and the surrounding environment in the process of community succession.Different successional stages of N.tangutorum nebkhas result in differences in the community structure and composition,thereby strongly affecting the distribution of soil nutrients and ecosystem stability.However,the ecological stoichiometry of N.tangutorum nebkhas in different successional stages remains poorly understood.Understanding the stoichiometric homeostasis of N.tangutorum could provide insights into its adaptability to the arid and semi-arid desert environments.Therefore,we analyzed the stoichiometric characteristics of N.tangutorum in four successional stages,i.e.,rudimental,developing,stabilizing,and degrading stages using a homeostasis model in an oasis-desert ecotone of Northwest China.The results showed that soil organic carbon(SOC),total nitrogen(TN),and total phosphorus(TP)contents and their ratios in the 0-100 cm soil depth were significantly lower than the averages at regional and global scales and were weakly influenced by successional stages in the oasis-desert ecotone.TN and TP contents and C:N:P in the soil showed similar trends.Total carbon(TC)and TN contents in leaves were 450.69-481.07 and 19.72-29.35 g/kg,respectively,indicating that leaves of N.tangutorum shrubs had a high storage capacity for C and N.Leaf TC and TN contents and N:P ratio increased from the rudimental stage to the stabilizing stage and then decreased in the degrading stage,while the reverse trend was found for leaf C:N.Leaf TP content decreased from the rudimental stage to the degrading stage and changed significantly in late successional stages.N:P ratio was above the theoretical limit of 14,indicating that the growth of N.tangutorum shrubs was limited by P during successional stages.Leaf N,P,and N:P homeostasis in four successional stages was identified as''strictly homeostasis''.Redundancy analysis(RDA)revealed that soil acidity(pH)and the maximum water holding capacity were the main factors affecting C:N:P stoichiometric characteristics in N.tangutorum leaves.Our study demonstrated that N.tangutorum with a high degree of stoichiometric homeostasis could better cope with the arid desert environment.展开更多
Eighteen clones of Eucalyptus tereticornis （Sm.） were evaluated for three years by adopting randomized block design for various growth parameters at Hoshiarpur, Punjab, India and compared with two checks. Significan...Eighteen clones of Eucalyptus tereticornis （Sm.） were evaluated for three years by adopting randomized block design for various growth parameters at Hoshiarpur, Punjab, India and compared with two checks. Significant variations were recorded for height, diameter at breast height （DBH） and clear bole height （CBH）. The broad sense heritability was low to moderate for both height and CBH. The genetic gain for height and CBH increased substantially pe se with the increase in age of trees. The average genetic gain for thres years was recorded maximum for height （159.60%） followed by DBH （110.97%） and CBH （70.34%）. Clone 17 attained maximum DBH over other genotypes for second and third year followed by clones 14 and 11. Clone 5 showed an upward trend for DBH and maintained its superiority for CBH as the age of the tree increased. Similarly, clone 11 changed its ranking from 9th to 8th to 3rd for DBH and from 9th to 4th to 2nd for CBH, respectively for the age of one, two and three years. Nonetheless, clones 6 and 10 per- formed poorly for all the characters studied. Clones 17, 14 and 5 were found to be the most promising clones for commercial deployment.展开更多
Chinese Torreya grandis(Torreya grandis cv.Merrillii)is a unique economic tree species in China.Intensive management related to application of chemical fertilizer and herbicides caused serious soil quality degradation...Chinese Torreya grandis(Torreya grandis cv.Merrillii)is a unique economic tree species in China.Intensive management related to application of chemical fertilizer and herbicides caused serious soil quality degradation of Chinese Torreya grandis plantations.Totally,120 soil samples were collected from the main disbtributed areas of Chinese Torreya grandis in Southeastern China.In this area,soil pH values varied from 3.68 to 6.78,with a median value of 4.91,implying a trend of acidification.The average concentrations of organic matter,available nitrogen,available phosphorus and available potassium were 27.52 g kg^(-1),135.77 mg kg^(-1),15.12 mg kg^(-1),and 153.43 mg kg^(-1),respectively.The results of spatial analysis revealed that target variables had clear spatial patterns.The soil fertility was relevantly high in most of the study area,with soil nutrient imbalances existing.The stand age had a large effect on soil properties,which were also mainly influenced by human activities.Therefore,it is necessary to change the fertilization method for a sustainable management of Torreya grandis plantation.展开更多
Abies gracilis Kom.(Pinaceae)is one of the rarest and endangered conifers in the Russian flora,which must be cultivated ex situ to ensure its survival.Cuttings of A.gracilis do not take root without biostimulants.We u...Abies gracilis Kom.(Pinaceae)is one of the rarest and endangered conifers in the Russian flora,which must be cultivated ex situ to ensure its survival.Cuttings of A.gracilis do not take root without biostimulants.We used a selection of biostimulants,concentrations,and conditions of their use to significantly increase Abies gracilis rooting,and to accelerate the production of planting material,and to reduce rooting time to one season.We tested 4 rooting systems:IBA,IBA with glucose and glycine,and original biostimulants(S-try and S-5).The original S-5 biostimulating system had the most balanced ratio of components.The number of rooted samples increased 2.7 times and the length of roots increased 1.8 time when using S-5 as compared to IBA.S-try and S-5-original biostimulant systems were synthesized and collected in 2011 and 2014,respectively,and were tested in St.Petersburg Forest Technical University.展开更多
Background:Black locust(BL,Robinia pseudoacacia)is considered a promising tree species for reforestation due to its great ability to fix nitrogen.However,after two or three coppice-harvesting rotations,the productivit...Background:Black locust(BL,Robinia pseudoacacia)is considered a promising tree species for reforestation due to its great ability to fix nitrogen.However,after two or three coppice-harvesting rotations,the productivity of BL declines.Whether soil microbial communities are affected and how these groups correlate with the nitrogen mineralization process across multi-generation stands remains unclear.Methods:We investigated the composition and structure of free-living nitrogen-fixing microorganisms(diazotrophs)by sequencing the marker gene nifH and compared these results to levels of soil nitrogen mineralization in the bulk soil and rhizosphere in black locust plantations on Mount Tai,China.Results:The results showed multi-generation BL coppice plantations decreased the total soil nitrogen(N),soil phosphorus(P),soil microbial biomass N(MBN),soil microbial biomass C(MBC),soil nitrification rate(Rn),soil ammonification rate(Ra),and net soil N mineralization rate(Rm),but significantly increased the concentration of soil NH_(4þ)-N to maintain sufficient NO_(3)^(-)N.The dominant species in bulk soil and rhizosphere changed from Rhodopseudomonas(22.62%and 15.76%),unclassified_c_Alphaproteobacteria(22.37%and 29.28%),unclassified_o_Rhizobiales(15.40%and 13.31%),Bradyrhizobium(12.00%and 11.74%)in seedling plantations to Bradyrhizobium(45.95%and 47.86%)and Rhodopseudomonas(43.56%and 41.84%)in coppice plantations,respectively.Mantel test and Redundancy analysis(RDA)revealed that Rn,Ra,and Rm were the most important factors shaping the diazotrophic communities.Conclusions:Our results suggest that the multi-generation BL coppice plantation can homogenize soil diazotrophic communities,which is mainly regulated by the available N loss caused by nitrogen mineralization.Strengthening the management technology of coppice plantations will provide more beneficial external consumption.展开更多
Shrub expansion into arctic and alpine tundra is one of the prominent vegetation changes currently underway.We studied the expansion of shrub vegetation into high elevation tundra in the Kvarkush Range of the Northern...Shrub expansion into arctic and alpine tundra is one of the prominent vegetation changes currently underway.We studied the expansion of shrub vegetation into high elevation tundra in the Kvarkush Range of the Northern Ural mountains,Russia.Age structure analysis of the dominant shrub Juniperus sibirica Burgsd.seems to support ongoing upslope advance of shrubs,a process particularly active in the second half of the 20 th century.We found a close connection between the expansion of shrub vegetation and the general change in climatic conditions of the cold season(months with mean airtemperature below 0°Сfrom November to March).In general,the greatest influence on the distribution of J.sibirica is exerted by the climate conditions of the beginning(November-January)and the end(March)of the cold season.With increasing elevation,the correlation coefficients between the establishment of J.sibirica shrubs and the precipitation of the beginning of the cold season increased,and reached maximum values at the top elevation level of the study area.However,the upwards shift of J.sibirica into typical mountain tundra does not lead to changes in the ecological structure of vegetation at this stage,but simply a decrease in the area of mountain tundra.展开更多
Based on the 6-year-old young forests of 40 cypress(Cupressus funebris) families from four provenances(Fengdu County, Youyang County and Zhong County of Chongqing City, and Qiandao Lake in Zhejiang Province), differen...Based on the 6-year-old young forests of 40 cypress(Cupressus funebris) families from four provenances(Fengdu County, Youyang County and Zhong County of Chongqing City, and Qiandao Lake in Zhejiang Province), differences in growth traits between families and provenances were studied to select excellent families, so as to provide necessary data support for the upgrading of cypress seed gardens and inferior thinning of seed gardens. The results showed that there were significant differences in tree height, diameter at one meter height, crown width and growth potential between families and provenances. The coefficients of variation among families were 10.25%, 7.19%, 5.91% and 0.98%, respectively, and the coefficients of variation in tree height and diameter at one meter height among provenances were 7.25% and 12.58%, respectively, indicating that the tree height and diameter at one meter height of the superior cypress tree families were rich in variation among families and provenances, and there was potential for high-generation breeding. According to the selection rate of 15%, six excellent families for afforestation(Feng 8, Shi 4, Feng 1, Ye 14, Shi 3, and Ye 6) were screened. The average diameter at one meter height, tree height and crown width of the six excellent families were, respectively, 2.97 cm, 3.39 and 0.78 m, which were 18.82%, 12.70% and 15.42% higher than the family average, respectively, and 15.09%, 9.79% and 15.53% higher than the control group, respectively.展开更多
Regular grid of permanent sample plots (PSP) of ICP-Forests monitoring system was used for forest ecosystems biodiversity assessments and inventory. The supplementary features were added to the PSP structure to conduc...Regular grid of permanent sample plots (PSP) of ICP-Forests monitoring system was used for forest ecosystems biodiversity assessments and inventory. The supplementary features were added to the PSP structure to conduct biological diversity census: eight sample plots 1 × 1 m for geo-botanical description;two sample plots of 5 × 5 m each for description of the PSP’s undergrowth;one 25 × 25 m plot for coarse woody debris estimations;four soil inventory pits. The total number of PSP amounted to 248. Total data used are as following: 1) 1984 geo-botanical descriptions of vegetation belonging to ground cover layers made on 1 × 1 m sample plots;2) 496 descriptions of undergrowth on 5 × 5 m sample plots;3) 178 descriptions of woody debris on 25 × 25 m sample plots;4) 496 descriptions of soil inventory pits. General statistical indicators characterizing forest land cover diversity were calculated. Statistic indicators of α-diversity for the Karelian Isthmus forest vegetation cover have the following values: 1) m (mean number of species per PSP) = 26 species;2) σ (standard deviation) = 9.5 species;3) v (variation coefficient) = 36.5%;4) Р (deviation amplitude) = 60 – 7 = 53 species. β – diversity of forest ecosystems as well as γ – diversity also was studied on the base of information collected on the same regular grid of sample plots. It appears that sample plots distribution by species diversity gradation is well described by the standard curve of normal distribution for the entire Karelian Isthmus forest (determination coefficient of the curve being 95.2%) as well as for each type of forest. Hence, the criterion (standard) of biodiversity for forest ecosystems can be defined as the mean value of alpha diversity for each forest type group – m;and the standard deviation – σ, as a tool for assessing deviations from the standard. PSP locations are fixed using GPS technology, this allows biodiversity assessments at the same place in the next years for biodiversity trends estimations and consist the frame for systematic biodiversity inventory.展开更多
A major threat to biodiversity in North Dakota is the conversion of forested land to cultivable land, especially those that act as riparian buffers. To reverse this trend of transformation, a validation and prediction...A major threat to biodiversity in North Dakota is the conversion of forested land to cultivable land, especially those that act as riparian buffers. To reverse this trend of transformation, a validation and prediction model is necessary to assess the change. Spatial prediction within a Geographic Information System (GIS) using Kriging is a popular stochastic method. The objective of this study was to predict spatial and temporal transformation of a small agricultural watershed—Pipestem Creek in North Dakota;USA using satellite imagery from 1976 to 2015. To enhance the difference between forested land and non-forested land, a spectral transformation method—Tasseled-Cap’s Greenness Index (TCGI) was used. To study the spatial structure present in the imagery within the study period, semivariograms were generated. The Kriging prediction maps were post-classified using Remote Sensing techniques of change detection to obtain the direction and intensity of forest to non-forest change. TCGI generated higher values from 1976 to 2000 and it gradually reduced from 2000 to 2011 indicating loss of forested land.展开更多
Thinning is an effective management step for sustainable forest development,yet less attention is paid to the restoration of soil microbiota after thinning.In this study,both abundant and rare soil microbial communiti...Thinning is an effective management step for sustainable forest development,yet less attention is paid to the restoration of soil microbiota after thinning.In this study,both abundant and rare soil microbial communities(i.e.,bacterial,fungal),were evaluated under various thinning treatments in a mixed stand of Cunninghamia lanceolata and Sassafras tzumu using Mi Seq sequencing.Thinning did not significantly change either abundant or rare bacterial and fungal community composition,but affected their alpha diversity.The Shannon–Wiener indexes of rare fungal taxa under medium thinning were significantly lower than in the light thinning(P<0.05 level).Xanthobacteraceae dominated the abundant bacterial taxa,and Saitozyma and Mortierlla the abundant fungal taxa.The most common rare bacterial taxa varied;there was no prevalent rare fungal taxa under different thinnings.In addition,soil available nitrogen,total phosphorus,and p H had significant effects on rare bacterial taxa.Nutrients,especially available phosphorus,but not nitrogen,affected abundant and rare soil fungi.The results indicate that soil properties rather than plant factors affect abundant and rare microbial communities in soils of mixed stands.Thinning,through mediating soil properties,influences both abundant and rare bacterial and fungal communities in the mixed C.lanceolata and S.tzumu stand.展开更多
In total 36 superior clones of Dalbergia sissoo Roxb., screened from 300 selections conducted in natural and growing range of India and Nepal, were multiplied using single nodal cuttings and estab- lished to evaluate ...In total 36 superior clones of Dalbergia sissoo Roxb., screened from 300 selections conducted in natural and growing range of India and Nepal, were multiplied using single nodal cuttings and estab- lished to evaluate genotypexenvironmental interactions for adaptability and stability at the age of 30 months in three geographical locations in the state of Punjab, India. Clone 124 had maximum adaptability and stability （bi = 1.04） to perform exceedingly well over the locations. Clones 36 and 1 were stable with mean regression coefficient of 0.84 and 1.22, respectively. Nonetheless, clone 4 1 performed exceedingly well for all the characters to attain maximum population mean, and the perform- ance varied substantially across the locations. Therefore, clone 41 was considered as productive but non-adaptive clone. Though some of the clones were sensitive to sites, 14 clones for height, 16 for collar diameter, 12 for DBH and 7 for volume were relatively un-sensitive with higher regression coefficient. Nonetheless, clone 124 was the most Stable with average bi value of 1.04 and productive, which could play an important role in future breeding and commercial deployment of stable and produc- tive planting stock of Dalbergia sissoo.展开更多
Shorea robusta Gaertn. f.（Sal）is one of the important tim-ber-yielding plants in India, which dominates the vegetation of Terai landscape of Uttar Pradesh state in India forming various communities based on its asso...Shorea robusta Gaertn. f.（Sal）is one of the important tim-ber-yielding plants in India, which dominates the vegetation of Terai landscape of Uttar Pradesh state in India forming various communities based on its associations. The present study deals with delineation, map-ping and characterization of various communities of Sal （Shorea robusta） forests in Terai landscape of Uttar Pradesh, India ranging across over 16 districts. Field survey and visual interpretation based forest vegetation type classification and mapping was carried out as part of the project entitled ‘Biodiversity characterization at landscape level using remote sensing and GIS’. Indian Remote Sensing-P6 （Resourcesat-1） Linear Imaging Self Scanner-III satellite data was used during the study. The total area covered by different Sal forests was found to be approximately 2256.77 km2. Sal communities were identified and characterized based on their spectral properties, physiognomy and phytosociological charac-teristics. Following nine Sal communities were identified, delineated and mapped with reasonable accuracyviz.,Chandar,Damar, dry plains, moist plains, western alluvium, western alluvium plains, mixed moist deciduous, mixed dry deciduous andSiwalik. It is evident from the area estimates that mixed moist deciduous Sal is the most dominant commu-nity in the region covering around （1613.90 km2）, other major communi-ties were found as western alluvium plains Sal （362.44 km2）, mixed dry deciduous Sal （362.44 km2） and dry plains Sal （107.71 km2）. The Terai landscape of Uttar Pradesh faces tremendous anthropogenic pressure leading to deterioration of the forests. Community level information could be used monitoring the status as well as for micro level conserva-tion and planning of the Sal forests in Terai Landscape of Uttar Pradesh.展开更多
The data of field studies about mineral nutrient content in the biomass components of young birch stands （9-15 years old） in different forest growing conditions and soil types have been analyzed. In forest growing c...The data of field studies about mineral nutrient content in the biomass components of young birch stands （9-15 years old） in different forest growing conditions and soil types have been analyzed. In forest growing conditions on fertile soils （ASG, TSC and SP） the total amount of biomass produced by young birch stands divides into fractions as follows： stem wood 51.8%-59.5%; branch wood 9.8%-12.4%; foliage 5.7%-6.8%; stump wood and roots 25%-30%. In forest types on lean soils （TP） the same indices are 32.3%-41.8%, 18.2%-24.2%, 13.2%-16.1% and 26.8%-27.4%, respectively. The stand performance closely correlates with the basic nutrient （P, N, K, C and Mg） availability in forest soils. In lean typicpodzol soils （TP） the content of mineral nutrients is no higher than 20%-48% of that in more fertile soils （ASG, TSC and SP）. In young birch stands the take-up of mineral nutrients from 0-40 cm soil layer for developing the above-ground biomass makes a fairly small proportion of the total： up to 4.8%-6.2% for P; 4.9%-12.2% for N; 1.1%-4.1% for K; 11.6% for Ca; 0.8%-7.7% for Mg; in leaner soils the same indices are P 0.1%-0.4%, N 1%-1.5%, K 0.2%-0.6%, Ca 0.1%-0.9%, Mg 0.1%-0.8%, respectively. The analyses of pest damages in young birch stands confirm a hypothesis that the degree of pest damage depends on the stand vitality as described by the site index.展开更多
文摘The research was carried out on the territory of the Karelian Isthmus of the Leningrad Region using Sentinel-2B images and data from a network of ground sample plots. The ground sample plots are located in the studied territory mainly in a regular manner, laid and surveyed according to the ICP-Forests methodology with some additions. The total area of the sample plots is a small part of the entire study area. One of the objectives of the study was to determine the possibility of using the k-NN (nearest neighbor method) to assess the state of forests throughout the whole studied territory by joint statistical processing of data from ground sample plots and Sentinel-2B imagery. The data of the ground-based sample plots were divided into 2 equal parts, one for the application of the k-NN method, the second for checking the results of the method application. The systematic error in determining the mean damage class of the tree stands on sample plots by the k-NN method turned out to be zero, the random error is equal to one point. These results offer a possibility to determine the state of the forest in the entire study area. The second objective of the study was to examine the possibility of using the short-wave vegetation index (SWVI) to assess the state of forests. As a result, a close statistically reliable dependence of the average score of the state of plantations and the value of the SWVI index was established, which makes it possible to use the established relationship to determine the state of forests throughout the studied territory. The joint use and statistical processing of remotely sensed data and ground-based test areas by the two studied methods make it possible to assess the state of forests throughout the large studied area within the image. The results obtained can be used to monitor the state of forests in large areas and design appropriate forestry protective measures.
文摘The article considers the impact of forestry machines on the soil of the cutting areas and presents the results of the impact of harvesters of different classes(middlesmall,middle and heavy)and configurations of wheeled equipment and additional equipment on the soil of the cutting areas in the conditions of Kronoberg County(South of Sweden).Methods to reduce negative impact of wheeled harvesters on the soil of forests are proposed.The aim of the research is to assess the effect of the structural parameters of the wheel harvesters of different class on the soil of the cutting areas.Wheeled harvesters were loaded with 60 kN force.The results of experimental studies of the impact of wheeled harvesters on the forest soil are presented.Recommendations on the possibility of testing the results of research in the conditions of the rental base of the Western part of the North-Western Federal District of the Russian Federation are given.
文摘In this paper,the stability of the results of ultrasonic wood surface modification after long-term storage,including macroscopic properties and microstructure of specimens,was investigated.Specimens of aspen wood(Populus tremula)were processed by the developed ultrasonic method of wood surface modification in three different treatment modes and the surface hardness of the specimens was evaluated after processing and after storing the specimens for more than 5 years since long-term stability is an important factor for the use of ultrasonically modified sawn timber as construction and finishing materials.The obtained results of surface hardness measurements by the Leeb method showed that the decrease in hardness after long-term storage is approximately 6.6%for the lowest degree of treatment and approximately 3.4%and 2.4%for medium and high degrees of treatment,taking into account the fact of the average increase in surface hardness approximately 2–4 times,this decrease is insignificant.The internal structure of the specimens after storage was studied by scanning electron microscope(SEM),and deformations of the wood surface layer without damage or rupture were analyzed.The derived stable results confirm the potential of the ultrasonic method for wood surface modification.
基金supported by National Key Social Science Research Project(11&ZD042)Forestry Public Welfare Scientific Research Project of the State Forestry Administration in China(200904003)DAAD-K.C.Wong Postdoctoral Fellowship Programme,Germany
文摘To better promote forest resource management and strengthen the development of forest carbon sink marketization, this paper studied the accounting of forest carbon sinks from 2003 to 2008 based on a system of national accounts （SNA） and data from the latest forest resources inventory in China. The study calculated the value of forest carbon stocks at a total of RMB 817.13 × 10^9 yuan in 2003 and RMB 839.93×10^9 yuan in 2008, with an average annual increase of 0.55 % from an increase in physical carbon sinks. The total value of forest carbon sinks in 2003 and 2008 was RMB 26.73×10^9 yuan and RMB 29.77×10^9 yuan, respectively, with an average annual growth of 2.18 %. From 2003 to 2008, both stock and flow value of forest carbon sinks increased, but the total net flow value of carbon sinks decreased. The growth rate for the environmentally adjusted Gross Domestic Product （eaGDP） for China＇s forest carbon sinks was 17.23 %, outstripping the average growth rate of 9.5 % for the GDP during the same period. The study alsoindicates that China＇s forest carbon sinks affects the GDP in the range of 0.25-0.26 %, and its economic potential is not relatively huge.
基金supported by the Knowledge Innovation Program of the Chinese Academy of Science (No.KZCX2-EW-QN406)the National Natural Science Foundation of China (No.31170425,40871130)
文摘Many studies have shown soil degradation after the conversion of native forests to exotic Eucalyptus plantations. However, few studies have investigated the long-term impacts of short-rotation forestry practices on soil microorganisms. The impacts of Eucalyptus successive rotations on soil microbial communities were evaluated by comparing phospholipid fatty acid （PLFA） abundances, compositions, and enzyme activities of native Pinus massoniana plantations and adjacent 1st, 2nd, 3rd, 4th generation Eucalyptus plantations. The conversion from P. massoniana to Eucalyptus plantations significantly decreased soil microbial community size and enzyme activities, and increased microbial physiological stress. However, the PLFA abundances formed ＂U＂ shaped quadratic functions with Eucalyptus plantation age. Alternatively, physiological stress biomarkers, the ratios of monounsaturated to saturated fatty acid and Gram＋ to Gram- bacteria, formed ＂∩＂ shaped quadratic functions, and the ratio of cy17：0 to 16： 1ω7c decreased with plantation age. The activities of phenol oxidase, peroxidase, and acid phosphatase increased with Eucalyptus plantation age, while the cellobiobydrolase activity formed ＂U＂ shaped quadratic functions. Soil N：P, alkaline hydrolytic nitrogen, soil organic carbon, and understory cover largely explained the variation in PLFA profiles while soil N：P, alkaline hydrolytic nitrogen, and understory cover explained most of the variability in enzyme activity. In conclusion, soil microbial structure and function under Eucalyptus plantations were strongly impacted by plantation age. Most of the changes could be explained by altered soil resource availability and understory cover associated with successive planting of Eucalyptus. Our results highlight the importance of plantation age for assessing the impacts of plantation conversion as well as the importance of reducing disturbance for plantation management.
基金supported by National Natural Science Foundation of China(Grant No.3116015731560209)Application Fundamental Research Plan Project of Yunnan Province,China(Grant No.2012FD027)
文摘A total of 128 Simao pine trees （Pinus kesiya var. langbianensis） from three regions of Pu＇er City, Yunnan Province, People＇s Republic of China, were destructively sampled to obtain tree aboveground biomass （AGB）. Tree variables such as diameter at breast height and total height, and topographical factors such as altitude, aspect of slope, and degree of slope were recorded. We considered the region and site quality classes as the ran- dom-effects, and the topographic variables as the fixed- effects. We fitted a total of eight models as follows： least- squares nonlinear models （BM）, least-squares nonlinear models with the topographic factors （BMT）, nonlinear mixed-effects models with region as single random-effects （NLME-RE）, nonlinear mixed-effects models with site as single random-effects （NLME-SE）, nonlinear mixed-ef- fects models with the two-level nested region and site random-effects （TLNLME）, NLME-RE with the fixed-ef- fects of topographic factors （NLMET-RE）, NLME-SE with the fixed-effects of topographic factors （NLMET-SE）, and TLNLME with the fixed-effects of topographic factors （TLNLMET）. The eight models were compared by modelfitting and prediction statistics. The results showed： model fitting was improved by considering random-effects of region or site, or both. The models with the fixed-effects of topographic factors had better model fitting. According to AIC and BIC, the model fitting was ranked as TLNLME 〉 NLMET-RE 〉 NLME-RE.〉 NLMET-SE 〉 TLNLMET 〉 NLME-SE 〉 BMT 〉 BM. The differences among these models for model prediction were small. The model pre- diction was ranked as TLNLME 〉 NLME-RE 〉 NLME- SE 〉 NLMET-RE 〉 NLMET-SE 〉 TLNLMET 〉 BMT 〉 BM. However, all eight models had relatively high prediction precision （〉90 %）. Thus, the best model should be chosen based on the available data when using the model to predict individual tree AGB.
基金financially supported by the National Key Basic Research Development Program (No.2009CB119200)the Forestry Public Welfare Industry Scientific Research Project (No.200904029-3)
文摘In order to investigate the effect of invastion by pine wood nematode(PWN), this study analyzed several functional indices, i.e., the increment in DBH and stand volume and biomass, in the damaged stands with various mixed percentages of Pinus massoniana and P. thunbergii and with different levels of damage. According to the results of rate of change in increment of DBH and stand volume, the forest ecosystem resistance against PWN increased with a reduction in the mixed ratio of pine. The resistance was highest with a mixed percentage of 50%. The invasion of PWN changed the corresponding relationship of increment between DBH and stand volume(pure stands > 7:3 conifer and broadleaf > 6:4 conifer and broadleaf > 5:5 conifer and broadleaf) among the P. thunbergii stands when there is no damage, but for P. massoniana stands this phenomenon did not occur. For the increment rate of DBH and stand volume, this significant change in P. thunbergii forest indicates that the resistance of pure P. thunbergii forest was higher than that of P. massoniana. The invasion of PWN accelerates the succession from pure stands to mixed stands and then to the broadleaf evergreen stands.
基金This research was funded by the National Natural Science Foundation of China(41967009)the National Key Research and Development Program of China(2016YFC0501003).
文摘Nitraria tangutorum nebkhas are widely distributed in the arid and semi-arid desert areas of China.The formation and development of N.tangutorum nebkhas are the result of the interaction between vegetation and the surrounding environment in the process of community succession.Different successional stages of N.tangutorum nebkhas result in differences in the community structure and composition,thereby strongly affecting the distribution of soil nutrients and ecosystem stability.However,the ecological stoichiometry of N.tangutorum nebkhas in different successional stages remains poorly understood.Understanding the stoichiometric homeostasis of N.tangutorum could provide insights into its adaptability to the arid and semi-arid desert environments.Therefore,we analyzed the stoichiometric characteristics of N.tangutorum in four successional stages,i.e.,rudimental,developing,stabilizing,and degrading stages using a homeostasis model in an oasis-desert ecotone of Northwest China.The results showed that soil organic carbon(SOC),total nitrogen(TN),and total phosphorus(TP)contents and their ratios in the 0-100 cm soil depth were significantly lower than the averages at regional and global scales and were weakly influenced by successional stages in the oasis-desert ecotone.TN and TP contents and C:N:P in the soil showed similar trends.Total carbon(TC)and TN contents in leaves were 450.69-481.07 and 19.72-29.35 g/kg,respectively,indicating that leaves of N.tangutorum shrubs had a high storage capacity for C and N.Leaf TC and TN contents and N:P ratio increased from the rudimental stage to the stabilizing stage and then decreased in the degrading stage,while the reverse trend was found for leaf C:N.Leaf TP content decreased from the rudimental stage to the degrading stage and changed significantly in late successional stages.N:P ratio was above the theoretical limit of 14,indicating that the growth of N.tangutorum shrubs was limited by P during successional stages.Leaf N,P,and N:P homeostasis in four successional stages was identified as''strictly homeostasis''.Redundancy analysis(RDA)revealed that soil acidity(pH)and the maximum water holding capacity were the main factors affecting C:N:P stoichiometric characteristics in N.tangutorum leaves.Our study demonstrated that N.tangutorum with a high degree of stoichiometric homeostasis could better cope with the arid desert environment.
文摘Eighteen clones of Eucalyptus tereticornis （Sm.） were evaluated for three years by adopting randomized block design for various growth parameters at Hoshiarpur, Punjab, India and compared with two checks. Significant variations were recorded for height, diameter at breast height （DBH） and clear bole height （CBH）. The broad sense heritability was low to moderate for both height and CBH. The genetic gain for height and CBH increased substantially pe se with the increase in age of trees. The average genetic gain for thres years was recorded maximum for height （159.60%） followed by DBH （110.97%） and CBH （70.34%）. Clone 17 attained maximum DBH over other genotypes for second and third year followed by clones 14 and 11. Clone 5 showed an upward trend for DBH and maintained its superiority for CBH as the age of the tree increased. Similarly, clone 11 changed its ranking from 9th to 8th to 3rd for DBH and from 9th to 4th to 2nd for CBH, respectively for the age of one, two and three years. Nonetheless, clones 6 and 10 per- formed poorly for all the characters studied. Clones 17, 14 and 5 were found to be the most promising clones for commercial deployment.
基金the Natural Science Fundation of Zhejiang Province(LY20C160004)。
文摘Chinese Torreya grandis(Torreya grandis cv.Merrillii)is a unique economic tree species in China.Intensive management related to application of chemical fertilizer and herbicides caused serious soil quality degradation of Chinese Torreya grandis plantations.Totally,120 soil samples were collected from the main disbtributed areas of Chinese Torreya grandis in Southeastern China.In this area,soil pH values varied from 3.68 to 6.78,with a median value of 4.91,implying a trend of acidification.The average concentrations of organic matter,available nitrogen,available phosphorus and available potassium were 27.52 g kg^(-1),135.77 mg kg^(-1),15.12 mg kg^(-1),and 153.43 mg kg^(-1),respectively.The results of spatial analysis revealed that target variables had clear spatial patterns.The soil fertility was relevantly high in most of the study area,with soil nutrient imbalances existing.The stand age had a large effect on soil properties,which were also mainly influenced by human activities.Therefore,it is necessary to change the fertilization method for a sustainable management of Torreya grandis plantation.
基金This work was supported,in part,by the Department of Science and Innovation of the Yamalo-Nenets Autonomous District under the Government Contract No.01-15/4 dated 25.07.2012,by the Ministry of Education and Science of the Russian Federation under the Project No.2014/181-2220.
文摘Abies gracilis Kom.(Pinaceae)is one of the rarest and endangered conifers in the Russian flora,which must be cultivated ex situ to ensure its survival.Cuttings of A.gracilis do not take root without biostimulants.We used a selection of biostimulants,concentrations,and conditions of their use to significantly increase Abies gracilis rooting,and to accelerate the production of planting material,and to reduce rooting time to one season.We tested 4 rooting systems:IBA,IBA with glucose and glycine,and original biostimulants(S-try and S-5).The original S-5 biostimulating system had the most balanced ratio of components.The number of rooted samples increased 2.7 times and the length of roots increased 1.8 time when using S-5 as compared to IBA.S-try and S-5-original biostimulant systems were synthesized and collected in 2011 and 2014,respectively,and were tested in St.Petersburg Forest Technical University.
基金supported by the Agricultural Science and Technology Fund for Forestry Sci-tech Innovation Project of Shandong Province (No.2019LY005)the National Natural Science Foundation of China (No.31570705)+1 种基金Shandong Province Higher School Science and Technology Plan Project (No. J16LF09)and Shandong Province Natural Science Foundation (No. ZR2018PC006)
文摘Background:Black locust(BL,Robinia pseudoacacia)is considered a promising tree species for reforestation due to its great ability to fix nitrogen.However,after two or three coppice-harvesting rotations,the productivity of BL declines.Whether soil microbial communities are affected and how these groups correlate with the nitrogen mineralization process across multi-generation stands remains unclear.Methods:We investigated the composition and structure of free-living nitrogen-fixing microorganisms(diazotrophs)by sequencing the marker gene nifH and compared these results to levels of soil nitrogen mineralization in the bulk soil and rhizosphere in black locust plantations on Mount Tai,China.Results:The results showed multi-generation BL coppice plantations decreased the total soil nitrogen(N),soil phosphorus(P),soil microbial biomass N(MBN),soil microbial biomass C(MBC),soil nitrification rate(Rn),soil ammonification rate(Ra),and net soil N mineralization rate(Rm),but significantly increased the concentration of soil NH_(4þ)-N to maintain sufficient NO_(3)^(-)N.The dominant species in bulk soil and rhizosphere changed from Rhodopseudomonas(22.62%and 15.76%),unclassified_c_Alphaproteobacteria(22.37%and 29.28%),unclassified_o_Rhizobiales(15.40%and 13.31%),Bradyrhizobium(12.00%and 11.74%)in seedling plantations to Bradyrhizobium(45.95%and 47.86%)and Rhodopseudomonas(43.56%and 41.84%)in coppice plantations,respectively.Mantel test and Redundancy analysis(RDA)revealed that Rn,Ra,and Rm were the most important factors shaping the diazotrophic communities.Conclusions:Our results suggest that the multi-generation BL coppice plantation can homogenize soil diazotrophic communities,which is mainly regulated by the available N loss caused by nitrogen mineralization.Strengthening the management technology of coppice plantations will provide more beneficial external consumption.
基金part of the state assignment of the Institute of Plant and Animal Ecology,Ural Branch of the Russian Academy of Sciences(No.AAAA-A19-119111990097-4No.AAAA-A19-119031890084-6No.AAAA-A19-119111390057-4)。
文摘Shrub expansion into arctic and alpine tundra is one of the prominent vegetation changes currently underway.We studied the expansion of shrub vegetation into high elevation tundra in the Kvarkush Range of the Northern Ural mountains,Russia.Age structure analysis of the dominant shrub Juniperus sibirica Burgsd.seems to support ongoing upslope advance of shrubs,a process particularly active in the second half of the 20 th century.We found a close connection between the expansion of shrub vegetation and the general change in climatic conditions of the cold season(months with mean airtemperature below 0°Сfrom November to March).In general,the greatest influence on the distribution of J.sibirica is exerted by the climate conditions of the beginning(November-January)and the end(March)of the cold season.With increasing elevation,the correlation coefficients between the establishment of J.sibirica shrubs and the precipitation of the beginning of the cold season increased,and reached maximum values at the top elevation level of the study area.However,the upwards shift of J.sibirica into typical mountain tundra does not lead to changes in the ecological structure of vegetation at this stage,but simply a decrease in the area of mountain tundra.
基金Supported by Assistance Fund for National Seed Base of Forest Tree
文摘Based on the 6-year-old young forests of 40 cypress(Cupressus funebris) families from four provenances(Fengdu County, Youyang County and Zhong County of Chongqing City, and Qiandao Lake in Zhejiang Province), differences in growth traits between families and provenances were studied to select excellent families, so as to provide necessary data support for the upgrading of cypress seed gardens and inferior thinning of seed gardens. The results showed that there were significant differences in tree height, diameter at one meter height, crown width and growth potential between families and provenances. The coefficients of variation among families were 10.25%, 7.19%, 5.91% and 0.98%, respectively, and the coefficients of variation in tree height and diameter at one meter height among provenances were 7.25% and 12.58%, respectively, indicating that the tree height and diameter at one meter height of the superior cypress tree families were rich in variation among families and provenances, and there was potential for high-generation breeding. According to the selection rate of 15%, six excellent families for afforestation(Feng 8, Shi 4, Feng 1, Ye 14, Shi 3, and Ye 6) were screened. The average diameter at one meter height, tree height and crown width of the six excellent families were, respectively, 2.97 cm, 3.39 and 0.78 m, which were 18.82%, 12.70% and 15.42% higher than the family average, respectively, and 15.09%, 9.79% and 15.53% higher than the control group, respectively.
文摘Regular grid of permanent sample plots (PSP) of ICP-Forests monitoring system was used for forest ecosystems biodiversity assessments and inventory. The supplementary features were added to the PSP structure to conduct biological diversity census: eight sample plots 1 × 1 m for geo-botanical description;two sample plots of 5 × 5 m each for description of the PSP’s undergrowth;one 25 × 25 m plot for coarse woody debris estimations;four soil inventory pits. The total number of PSP amounted to 248. Total data used are as following: 1) 1984 geo-botanical descriptions of vegetation belonging to ground cover layers made on 1 × 1 m sample plots;2) 496 descriptions of undergrowth on 5 × 5 m sample plots;3) 178 descriptions of woody debris on 25 × 25 m sample plots;4) 496 descriptions of soil inventory pits. General statistical indicators characterizing forest land cover diversity were calculated. Statistic indicators of α-diversity for the Karelian Isthmus forest vegetation cover have the following values: 1) m (mean number of species per PSP) = 26 species;2) σ (standard deviation) = 9.5 species;3) v (variation coefficient) = 36.5%;4) Р (deviation amplitude) = 60 – 7 = 53 species. β – diversity of forest ecosystems as well as γ – diversity also was studied on the base of information collected on the same regular grid of sample plots. It appears that sample plots distribution by species diversity gradation is well described by the standard curve of normal distribution for the entire Karelian Isthmus forest (determination coefficient of the curve being 95.2%) as well as for each type of forest. Hence, the criterion (standard) of biodiversity for forest ecosystems can be defined as the mean value of alpha diversity for each forest type group – m;and the standard deviation – σ, as a tool for assessing deviations from the standard. PSP locations are fixed using GPS technology, this allows biodiversity assessments at the same place in the next years for biodiversity trends estimations and consist the frame for systematic biodiversity inventory.
文摘A major threat to biodiversity in North Dakota is the conversion of forested land to cultivable land, especially those that act as riparian buffers. To reverse this trend of transformation, a validation and prediction model is necessary to assess the change. Spatial prediction within a Geographic Information System (GIS) using Kriging is a popular stochastic method. The objective of this study was to predict spatial and temporal transformation of a small agricultural watershed—Pipestem Creek in North Dakota;USA using satellite imagery from 1976 to 2015. To enhance the difference between forested land and non-forested land, a spectral transformation method—Tasseled-Cap’s Greenness Index (TCGI) was used. To study the spatial structure present in the imagery within the study period, semivariograms were generated. The Kriging prediction maps were post-classified using Remote Sensing techniques of change detection to obtain the direction and intensity of forest to non-forest change. TCGI generated higher values from 1976 to 2000 and it gradually reduced from 2000 to 2011 indicating loss of forested land.
基金the Sino-German Cooperation Forestry Major Scientific Research Project(zdczhz2021ky09)the National Natural Science Foundation of China(31971487 and 42277245).
文摘Thinning is an effective management step for sustainable forest development,yet less attention is paid to the restoration of soil microbiota after thinning.In this study,both abundant and rare soil microbial communities(i.e.,bacterial,fungal),were evaluated under various thinning treatments in a mixed stand of Cunninghamia lanceolata and Sassafras tzumu using Mi Seq sequencing.Thinning did not significantly change either abundant or rare bacterial and fungal community composition,but affected their alpha diversity.The Shannon–Wiener indexes of rare fungal taxa under medium thinning were significantly lower than in the light thinning(P<0.05 level).Xanthobacteraceae dominated the abundant bacterial taxa,and Saitozyma and Mortierlla the abundant fungal taxa.The most common rare bacterial taxa varied;there was no prevalent rare fungal taxa under different thinnings.In addition,soil available nitrogen,total phosphorus,and p H had significant effects on rare bacterial taxa.Nutrients,especially available phosphorus,but not nitrogen,affected abundant and rare soil fungi.The results indicate that soil properties rather than plant factors affect abundant and rare microbial communities in soils of mixed stands.Thinning,through mediating soil properties,influences both abundant and rare bacterial and fungal communities in the mixed C.lanceolata and S.tzumu stand.
文摘In total 36 superior clones of Dalbergia sissoo Roxb., screened from 300 selections conducted in natural and growing range of India and Nepal, were multiplied using single nodal cuttings and estab- lished to evaluate genotypexenvironmental interactions for adaptability and stability at the age of 30 months in three geographical locations in the state of Punjab, India. Clone 124 had maximum adaptability and stability （bi = 1.04） to perform exceedingly well over the locations. Clones 36 and 1 were stable with mean regression coefficient of 0.84 and 1.22, respectively. Nonetheless, clone 4 1 performed exceedingly well for all the characters to attain maximum population mean, and the perform- ance varied substantially across the locations. Therefore, clone 41 was considered as productive but non-adaptive clone. Though some of the clones were sensitive to sites, 14 clones for height, 16 for collar diameter, 12 for DBH and 7 for volume were relatively un-sensitive with higher regression coefficient. Nonetheless, clone 124 was the most Stable with average bi value of 1.04 and productive, which could play an important role in future breeding and commercial deployment of stable and produc- tive planting stock of Dalbergia sissoo.
基金part of the Department of Space/Department of Biotechnology sponsored project entitled "Biodiversity Characterization at Landscape level using Remote Sensing and GIS for Uttar Pradesh state except Vindhyan Hills"
文摘Shorea robusta Gaertn. f.（Sal）is one of the important tim-ber-yielding plants in India, which dominates the vegetation of Terai landscape of Uttar Pradesh state in India forming various communities based on its associations. The present study deals with delineation, map-ping and characterization of various communities of Sal （Shorea robusta） forests in Terai landscape of Uttar Pradesh, India ranging across over 16 districts. Field survey and visual interpretation based forest vegetation type classification and mapping was carried out as part of the project entitled ‘Biodiversity characterization at landscape level using remote sensing and GIS’. Indian Remote Sensing-P6 （Resourcesat-1） Linear Imaging Self Scanner-III satellite data was used during the study. The total area covered by different Sal forests was found to be approximately 2256.77 km2. Sal communities were identified and characterized based on their spectral properties, physiognomy and phytosociological charac-teristics. Following nine Sal communities were identified, delineated and mapped with reasonable accuracyviz.,Chandar,Damar, dry plains, moist plains, western alluvium, western alluvium plains, mixed moist deciduous, mixed dry deciduous andSiwalik. It is evident from the area estimates that mixed moist deciduous Sal is the most dominant commu-nity in the region covering around （1613.90 km2）, other major communi-ties were found as western alluvium plains Sal （362.44 km2）, mixed dry deciduous Sal （362.44 km2） and dry plains Sal （107.71 km2）. The Terai landscape of Uttar Pradesh faces tremendous anthropogenic pressure leading to deterioration of the forests. Community level information could be used monitoring the status as well as for micro level conserva-tion and planning of the Sal forests in Terai Landscape of Uttar Pradesh.
文摘The data of field studies about mineral nutrient content in the biomass components of young birch stands （9-15 years old） in different forest growing conditions and soil types have been analyzed. In forest growing conditions on fertile soils （ASG, TSC and SP） the total amount of biomass produced by young birch stands divides into fractions as follows： stem wood 51.8%-59.5%; branch wood 9.8%-12.4%; foliage 5.7%-6.8%; stump wood and roots 25%-30%. In forest types on lean soils （TP） the same indices are 32.3%-41.8%, 18.2%-24.2%, 13.2%-16.1% and 26.8%-27.4%, respectively. The stand performance closely correlates with the basic nutrient （P, N, K, C and Mg） availability in forest soils. In lean typicpodzol soils （TP） the content of mineral nutrients is no higher than 20%-48% of that in more fertile soils （ASG, TSC and SP）. In young birch stands the take-up of mineral nutrients from 0-40 cm soil layer for developing the above-ground biomass makes a fairly small proportion of the total： up to 4.8%-6.2% for P; 4.9%-12.2% for N; 1.1%-4.1% for K; 11.6% for Ca; 0.8%-7.7% for Mg; in leaner soils the same indices are P 0.1%-0.4%, N 1%-1.5%, K 0.2%-0.6%, Ca 0.1%-0.9%, Mg 0.1%-0.8%, respectively. The analyses of pest damages in young birch stands confirm a hypothesis that the degree of pest damage depends on the stand vitality as described by the site index.
