For sustainable forest management, understanding the ecological factors that determine vegetation composition are important. Here, the relation between the vegetation composition and environmental factors(elevation, a...For sustainable forest management, understanding the ecological factors that determine vegetation composition are important. Here, the relation between the vegetation composition and environmental factors(elevation, aspect, slope, CaCO3, K, P, C, N, C/N, bulk density,soil porosity, saturation moisture content, EC, pH, sand, silt and clay) was investigated in the Khonj forests, Fars Province, Iran. Characteristic land units, each 200 m2, were chosen for sampling to analyze species composition, soil characteristics and topographic factors. The floristic data were classified using a two-way indicator species analysis(TWINSPAN). Means were then compared using an ANOVA and Duncan multiple range test to detect any variations between groups. Also, the Kaiser–Meyer–Olkin index and Bartlett test were used to measure sampling adequacy. The four vegetation groups identified comprised the species Achillea wilhelmsii, Tanacetum parthenium,Convolvulus spinosus, Capparis spinosa. A detrended canonical correspondence analysis(DCCA) ordination diagram clearly illustrated the relationship between vegetation and environmental factors. According to the results,group 1 with A. wilhelmsii as the indicator species has a positive relation with slope and elevation. T. parthenium was the indicator species of group 2, that appears in areas with high silt and low bulk density and sand. The results showed that group 3 with Convolvulus spinosus as the indicator species was distributed in soils with high bulk density, low silt and pH as well. Group 4 with C. spinosa as the indicator species occurs in sandy soils and low slopes.Using DCCA, we determined the relationship between species and environmental factors more accurately. Results of this study can be used to restore vegetation or maintain species composition in ecological sensitive areas.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
We investigated whether species richness, diversity and density of understory herbaceous plants differed along logging(gap) and grazing(primarily by cattle) disturbance gradients, and sought to identify drivers of ric...We investigated whether species richness, diversity and density of understory herbaceous plants differed along logging(gap) and grazing(primarily by cattle) disturbance gradients, and sought to identify drivers of richness, diversity and density of understory vegetation of logged sites. A factorial experiment was conducted in the mixed conifer forest of Gidakom in Western Bhutan. Levels of the logging treatment included small(0.15 – 0.24 ha), medium(0.25 – 0.35 ha) and large(0.36 – 1.31 ha) gaps. The grazing treatment included grazed(primarily by cattle) and ungrazed(where herbivores were excluded by a fence) plots nested within each gap. Data were collected from 12 gaps(4 replicates at each level of logging) using the point intercept method. Shannon Weaver Diversity and Margalef's indices were used to estimate species diversity and describe species richness, respectively. Soil samples were analyzed for pH and nutrients. The interaction effect of logging and grazing was significant(p≤0.001) only on species diversity. Relative to ungrazed areas, species diversity was significantly higher(0.01≤p≤0.05) in medium grazed gaps. Under grazed conditions, soil P was negatively correlated with gap size and species diversity. While species diversity was positivelycorrelated(0.01≤p≤0.05) with soil N in grazed plots species richness was positively correlated(0.001≤p≤0.01) with soil N in ungrazed plots. Relative density of Yushania microphylla and Carex nubigena were higher under ungrazed conditions. Our study suggests that the combined effect of cattle grazing and logging results in higher species diversity of understory vegetation in medium and grazed gaps in mixed conifer forests of Bhutan,whereas increase or decrease in relative density of major species is determined primarily by the independent effects of grazing and logging. From management perspective, forest managers must refrain from creating large gaps to avoid loss of nutrients(mainly P and N), which may eventually affect tree regeneration. Managers intending to maintain understory vegetation diversity must consider the combined effects of grazing and logging, ensuring low to moderate grazing pressure.展开更多
English yew Taxus baccata L. has been catalogued as endangered tree species and prone to extinction in Austria as well as many other parts of Europe. The present work is based on the comparison of the natural populati...English yew Taxus baccata L. has been catalogued as endangered tree species and prone to extinction in Austria as well as many other parts of Europe. The present work is based on the comparison of the natural population of two gene conservation forests from different geographic locations in Austria where the spatial structure, regeneration status and possible conservation measures are examined. The pole stand distribution varied distinctly in each sites. The total no of individuals per ha (DBH ≥5 cm), average DBH and average height were 492 n.hm^-2, 8.8 cm and 6.3 m in Stiwollgraben whereas in Leininger Riese 45 n.hm^-2, 16.3 cm and 7.6 m respectively. Over 79% of the Stiwollgraben population were represented the good health condition, while in Leininger Riese it was less then 49 % which means population of Stiwollgraben is in better condition compared to Leininger Riese. The sites differed considerably in the pattern of regeneration but pattern were consistent with the dynamics depicted by the age distribution. Considering the one-year-old seedlings Stiwollgraben contains 13 019 individuals.hm^-2 whereas Leininger Riese only 1 368. Surprisingly there were no any saplings in respect of 51 to 150 cm height classes in both sites and 30 to 50 cm in Stiwollgraben. In that context the conservation of English yew on the forest level may require well-managed reserves and long-term rotations between harvest events, protection from the herbivore and reduction of competition, which will enhance the long-term viability of the species.展开更多
The original version of this article unfortunately contained three mistakes. (1) The spelling of the [A. Nishad'] name was incorrect. The corrected spelling is given below.
Hilly or mountainous terrain occupies around 12% of the area of Bangladesh.Natural resources associated with Bangladesh's hill are forest resources,biodiversity,minerals,and agricultural crops.Natural resources ha...Hilly or mountainous terrain occupies around 12% of the area of Bangladesh.Natural resources associated with Bangladesh's hill are forest resources,biodiversity,minerals,and agricultural crops.Natural resources have been exploited in the recent four decades due to excessive clearing of hill forest cover,resulting in loss of species richness, impacts related to increased water flow variability, increased hill slope erosion and flooding intensity, and a gradual decrease in the extent of hill area in Bangladesh.This review explores the major causes and effects of depletion of natural resources by linking drivers,pressures and the related impacts.A review has been conducted to structure the effects on the hilly areas and describe the responses to minimize them in the associated DPSIR framework.Population growth has been identified as a major driver contributing to high deforestation rates.This may negatively effect agricultural productivity and increase the frequency of serious flooding.Slash and burn cultivation also impacts the regeneration of evergreen forests,which may accelerate soil erosion. Due to this and other factors,local people are facing a deficits of natural resources(food,fodder,fuel wood and water),which exacerbates the effects of poverty. Future research should try to facilitate decision making for sustainable utilization of natural resources management in the hilly areas of Bangladesh. Additional conservation measures should be developed to increase the resilience of ecosystems at national and regional levels.展开更多
Anthropogenic disturbances influence plant regeneration and species diversity, which impact the conservation status of protected areas. A study was conducted in the Sitakund Botanical Garden and Eco-park(SBGE), Chitta...Anthropogenic disturbances influence plant regeneration and species diversity, which impact the conservation status of protected areas. A study was conducted in the Sitakund Botanical Garden and Eco-park(SBGE), Chittagong,Bangladesh to analyze the natural regeneration and tree species diversity in disturbed and less disturbed zones. Stratified and systematic random sampling was used to select 50 sample plots from each of the two zones. A total number of 109 plant species from 43 families were recorded in the study; of which 93 species were of natural origin while the rest were planted. From the species with natural origin 66 were tree species, 9 were shrub species and 18 were climbers. Species richness, density of regeneration and disturbance index in the height classes(0- 0.5 m)and(dbh > 6 cm) indicated significant differences between the zones. The study analyzed how disturbances affect species diversity in the area. It was found that species richness and basal area are negatively related with disturbances. Moreover,density(N/ha) of trees was more likely to decrease with increasing tree height that reflects the huge demand of local people to harvest large trees as part of their income generating activities. The study findings have implications for future management decisions of the SGBE. To restore these ecosystems, management should focus on both biodiversity conservation and providing benefits to local people without hampering forest ecosystems.展开更多
We examined the impact of picnic activities on forest diversity, structure, regeneration and vitality of tree species in the Bhawal National Park of Bangladesh. The study area was classified as a non-used, occasionall...We examined the impact of picnic activities on forest diversity, structure, regeneration and vitality of tree species in the Bhawal National Park of Bangladesh. The study area was classified as a non-used, occasionally used and frequently used area on the basis of the intensity of the picnic activities. A total of 43 plant species were enumerated in the whole study area. The highest plant species richness (41 species) was observed in the non-used area whereas the lowest species richness (11 species) in the frequently used area. The diversity index decreased with the increase of picnic intensity whereas the concentration of dominance increased. Density of all plant groups except mature trees, and the basal area of the mature trees showed a declining trend from the non-used to frequently used area. The frequently used area exhibited very poor regeneration. Tree vitality decreased with the increase of picnic intensity. The relevance of our study as a basis for further research to determine the impact of tourism on biodiversity in Bangladesh is discussed.展开更多
Zeolitites (ZTs) are rocks containing more than 50% of zeolite minerals and are known to be a suitable material for agricultural purposes by improving soil physicochemical properties and nitrogen (N) use efficiency. H...Zeolitites (ZTs) are rocks containing more than 50% of zeolite minerals and are known to be a suitable material for agricultural purposes by improving soil physicochemical properties and nitrogen (N) use efficiency. However, little is known about their effects on soil microbial biomass. This study aimed to evaluate short-term effects of different chabazite-rich ZT (CHAZT) amendments on soil microbial biomass and activity. A silty-clay agricultural soil was amended in three different ways, including the addition of natural (5% and 15%) and NH_4^+-enriched (10%) CHAZT. Soil dissolved organic carbon (C), total dissolved N, NH_4^+, NO_3^-, NO_2^-, microbial biomass C and N, and ergosterol were measured periodically over 16 d in a laboratory incubation. To verify the microbial immobilization of the N derived from NH_4^+-enriched CHAZT, a high15N source was used for enriching the mineral to measure the microbial biomass δ15N signature. An increase in the ergosterol content was observed in the soil amended with 5% natural CHAZT. However, no similar result was observed in the soil amended with 15% natural CHAZT, suggesting that the fungal biomass was favored at a lower CHAZT application rate. In the soil amended with NH+ 4-enriched CHAZT, microbial biomass N was related to NO_3^-production over time and inversely related to NH_4^+, suggesting high nitrification process. Isotopic measurements on microbial biomass confirmed immediate assimilation of N derived from NH_4^+-enriched CHAZT. These results suggested that the NH_4^+-enriched CHAZT used in this study supplied an immediately available N pool to the microbial biomass.展开更多
Based on the global distribution of land and soil quality and the world population,future trends in the agricultural use of land and soil resources are described,which will severely compromise future global food and f...Based on the global distribution of land and soil quality and the world population,future trends in the agricultural use of land and soil resources are described,which will severely compromise future global food and fiber production through the increase and the spatial changes of world population,through the loss of fertile land caused by insufficient soil management and through urbanisation and industrialization Moreover,future changes in life style and the increasing demand for food and bioenergy,trough changes in world economy,through climate change and a worldwide decrease in fresh water supply,sustainable land use for the production of food and fiber will be under threat.Until 2050 global food production must be doubled for satisfying global needs.Our scenarios should help to preview future changes,to counterbalance and to mitigate possible negative impacts,thus sustaining global food security.展开更多
Diffusive gradients in thin films(DGT)measurements have been shown to outperform other phosphorus(P)tests in soils with strong P sorption,but this has not been confirmed for moderately weathered European soils.We comp...Diffusive gradients in thin films(DGT)measurements have been shown to outperform other phosphorus(P)tests in soils with strong P sorption,but this has not been confirmed for moderately weathered European soils.We compared the performance of DGT in predicting wheat grain yield in Swedish long-term fertility experiments with those of standard intensity(water-extractable P(P-H2O))and quantity(ammonium lactate-extractable P(P-AL))tests.A Mitscherlich-type model was used to fit wheat yield response to P application rates(0,15,30 or 35,and 45 kg P ha-1 year-1)in each individual trial replicate to estimate the maximum yield.For trials with clear plateau-type yield responses and the goodness of fit(R2)>0.75,relative yields(RYs)were calculated for each P treatment and plotted against the soil P test results(n=143).The goodness of the Mitscherlich-type fits decreased in the following order:DGT-measured P(P-DGT)(R2=0.35)>P-H2O(R2=0.18)>P-AL(R2=0.13).When excluding soils with P-AL:P-DGT≥0.1 L g-1,R2 was considerably improved to 0.55 for P-AL,0.46 for P-H2O,and 0.65 for P-DGT(n=61).At 95%of maximum yield,the upper limit of P deficiency for P-DGT was 44.8(the soils with P-AL:P-DGT<0.1 L g-1)and 61.9μg L-1(all soils),falling within the range reported for other European and Australian soils(6.0–142μg L-1).We show that in the investigated Swedish soils,DGT performed better than the quantity and intensity tests,which is attributed to its ability to capture P diffusion and resupply from the soil solid phase,similar to plant roots in the rhizosphere.展开更多
During a survey on corticolous Dothideomycetes,several collections with ascospores matching the genera Asteromassaria and Stigmatomassaria(Pleomassariaceae,Pleosporales)were revealed from dead corticated twigs of Acer...During a survey on corticolous Dothideomycetes,several collections with ascospores matching the genera Asteromassaria and Stigmatomassaria(Pleomassariaceae,Pleosporales)were revealed from dead corticated twigs of Acer,Carpinus and Tamarix.Closer morphological examination showed that their ascomata were apothecial,with a hamathecium consisting of septate,branched paraphyses,which are apically swollen at maturity.Several collections were cultured and sequenced,and a Blast search of their nuc 28S rDNA sequences revealed dothideomycetous affiliation,but without a close match to a specific family or order.Phylogenetic analyses of a multigene matrix containing a representative selection of Dothideomycetes from four genes(nuc 18S rDNA,nuc 28S rDNA,rpb2 and tef1)revealed placement within Dothideomycetes but without a supported familial or ordinal affiliation.Based on the phylogenetic analyses and morphological investigations,the new genera Asterodiscus and Stigmatodiscus,with the two new species A.tamaricis and S.enigmaticus,are described and illustrated,and placed in the new family Stigmatodiscaceae and new order Stigmatodiscales.展开更多
More than 100 recent collections of Valsaria sensu lato mostly from Europe were used to elucidate the species composition within the genus.Multigene phylogeny based on SSU,LSU,ITS,rpb2 and tef1 sequences revealed a mo...More than 100 recent collections of Valsaria sensu lato mostly from Europe were used to elucidate the species composition within the genus.Multigene phylogeny based on SSU,LSU,ITS,rpb2 and tef1 sequences revealed a monophyletic group of ten species within the Dothideomycetes,belonging to three morphologically similar genera.This group could not be accommodated in any known family and are thus classified in the new family Valsariaceae and the new order Valsariales.The genus Valsaria sensu stricto comprises V.insitiva,V.robiniae,V.rudis,V.spartii,V.lopadostomoides sp.nov.and V.neotropica sp.nov.,which are phylogenetically well-defined,but morphologically nearly indistinguishable species.The new monotypic genus Bambusaria is introduced to accommodate Valsaria bambusae.Munkovalsaria rubra and Valsaria fulvopruinata are combined in Myrmaecium,a genus traditionally treated as a synonym of Valsaria,which comprises three species,with M.rubricosum as its generic type.This work is presented as a basis for additional species to be detected in future.展开更多
文摘For sustainable forest management, understanding the ecological factors that determine vegetation composition are important. Here, the relation between the vegetation composition and environmental factors(elevation, aspect, slope, CaCO3, K, P, C, N, C/N, bulk density,soil porosity, saturation moisture content, EC, pH, sand, silt and clay) was investigated in the Khonj forests, Fars Province, Iran. Characteristic land units, each 200 m2, were chosen for sampling to analyze species composition, soil characteristics and topographic factors. The floristic data were classified using a two-way indicator species analysis(TWINSPAN). Means were then compared using an ANOVA and Duncan multiple range test to detect any variations between groups. Also, the Kaiser–Meyer–Olkin index and Bartlett test were used to measure sampling adequacy. The four vegetation groups identified comprised the species Achillea wilhelmsii, Tanacetum parthenium,Convolvulus spinosus, Capparis spinosa. A detrended canonical correspondence analysis(DCCA) ordination diagram clearly illustrated the relationship between vegetation and environmental factors. According to the results,group 1 with A. wilhelmsii as the indicator species has a positive relation with slope and elevation. T. parthenium was the indicator species of group 2, that appears in areas with high silt and low bulk density and sand. The results showed that group 3 with Convolvulus spinosus as the indicator species was distributed in soils with high bulk density, low silt and pH as well. Group 4 with C. spinosa as the indicator species occurs in sandy soils and low slopes.Using DCCA, we determined the relationship between species and environmental factors more accurately. Results of this study can be used to restore vegetation or maintain species composition in ecological sensitive areas.
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support of the Government of Austria with funds routed through the sterreischer Austauschdienst(OeAD)
文摘We investigated whether species richness, diversity and density of understory herbaceous plants differed along logging(gap) and grazing(primarily by cattle) disturbance gradients, and sought to identify drivers of richness, diversity and density of understory vegetation of logged sites. A factorial experiment was conducted in the mixed conifer forest of Gidakom in Western Bhutan. Levels of the logging treatment included small(0.15 – 0.24 ha), medium(0.25 – 0.35 ha) and large(0.36 – 1.31 ha) gaps. The grazing treatment included grazed(primarily by cattle) and ungrazed(where herbivores were excluded by a fence) plots nested within each gap. Data were collected from 12 gaps(4 replicates at each level of logging) using the point intercept method. Shannon Weaver Diversity and Margalef's indices were used to estimate species diversity and describe species richness, respectively. Soil samples were analyzed for pH and nutrients. The interaction effect of logging and grazing was significant(p≤0.001) only on species diversity. Relative to ungrazed areas, species diversity was significantly higher(0.01≤p≤0.05) in medium grazed gaps. Under grazed conditions, soil P was negatively correlated with gap size and species diversity. While species diversity was positivelycorrelated(0.01≤p≤0.05) with soil N in grazed plots species richness was positively correlated(0.001≤p≤0.01) with soil N in ungrazed plots. Relative density of Yushania microphylla and Carex nubigena were higher under ungrazed conditions. Our study suggests that the combined effect of cattle grazing and logging results in higher species diversity of understory vegetation in medium and grazed gaps in mixed conifer forests of Bhutan,whereas increase or decrease in relative density of major species is determined primarily by the independent effects of grazing and logging. From management perspective, forest managers must refrain from creating large gaps to avoid loss of nutrients(mainly P and N), which may eventually affect tree regeneration. Managers intending to maintain understory vegetation diversity must consider the combined effects of grazing and logging, ensuring low to moderate grazing pressure.
文摘English yew Taxus baccata L. has been catalogued as endangered tree species and prone to extinction in Austria as well as many other parts of Europe. The present work is based on the comparison of the natural population of two gene conservation forests from different geographic locations in Austria where the spatial structure, regeneration status and possible conservation measures are examined. The pole stand distribution varied distinctly in each sites. The total no of individuals per ha (DBH ≥5 cm), average DBH and average height were 492 n.hm^-2, 8.8 cm and 6.3 m in Stiwollgraben whereas in Leininger Riese 45 n.hm^-2, 16.3 cm and 7.6 m respectively. Over 79% of the Stiwollgraben population were represented the good health condition, while in Leininger Riese it was less then 49 % which means population of Stiwollgraben is in better condition compared to Leininger Riese. The sites differed considerably in the pattern of regeneration but pattern were consistent with the dynamics depicted by the age distribution. Considering the one-year-old seedlings Stiwollgraben contains 13 019 individuals.hm^-2 whereas Leininger Riese only 1 368. Surprisingly there were no any saplings in respect of 51 to 150 cm height classes in both sites and 30 to 50 cm in Stiwollgraben. In that context the conservation of English yew on the forest level may require well-managed reserves and long-term rotations between harvest events, protection from the herbivore and reduction of competition, which will enhance the long-term viability of the species.
文摘The original version of this article unfortunately contained three mistakes. (1) The spelling of the [A. Nishad'] name was incorrect. The corrected spelling is given below.
文摘Hilly or mountainous terrain occupies around 12% of the area of Bangladesh.Natural resources associated with Bangladesh's hill are forest resources,biodiversity,minerals,and agricultural crops.Natural resources have been exploited in the recent four decades due to excessive clearing of hill forest cover,resulting in loss of species richness, impacts related to increased water flow variability, increased hill slope erosion and flooding intensity, and a gradual decrease in the extent of hill area in Bangladesh.This review explores the major causes and effects of depletion of natural resources by linking drivers,pressures and the related impacts.A review has been conducted to structure the effects on the hilly areas and describe the responses to minimize them in the associated DPSIR framework.Population growth has been identified as a major driver contributing to high deforestation rates.This may negatively effect agricultural productivity and increase the frequency of serious flooding.Slash and burn cultivation also impacts the regeneration of evergreen forests,which may accelerate soil erosion. Due to this and other factors,local people are facing a deficits of natural resources(food,fodder,fuel wood and water),which exacerbates the effects of poverty. Future research should try to facilitate decision making for sustainable utilization of natural resources management in the hilly areas of Bangladesh. Additional conservation measures should be developed to increase the resilience of ecosystems at national and regional levels.
基金supported by the OG (sterreichische Orient-Gesellschaft Hammer Purgstall) Vienna, Austria
文摘Anthropogenic disturbances influence plant regeneration and species diversity, which impact the conservation status of protected areas. A study was conducted in the Sitakund Botanical Garden and Eco-park(SBGE), Chittagong,Bangladesh to analyze the natural regeneration and tree species diversity in disturbed and less disturbed zones. Stratified and systematic random sampling was used to select 50 sample plots from each of the two zones. A total number of 109 plant species from 43 families were recorded in the study; of which 93 species were of natural origin while the rest were planted. From the species with natural origin 66 were tree species, 9 were shrub species and 18 were climbers. Species richness, density of regeneration and disturbance index in the height classes(0- 0.5 m)and(dbh > 6 cm) indicated significant differences between the zones. The study analyzed how disturbances affect species diversity in the area. It was found that species richness and basal area are negatively related with disturbances. Moreover,density(N/ha) of trees was more likely to decrease with increasing tree height that reflects the huge demand of local people to harvest large trees as part of their income generating activities. The study findings have implications for future management decisions of the SGBE. To restore these ecosystems, management should focus on both biodiversity conservation and providing benefits to local people without hampering forest ecosystems.
文摘We examined the impact of picnic activities on forest diversity, structure, regeneration and vitality of tree species in the Bhawal National Park of Bangladesh. The study area was classified as a non-used, occasionally used and frequently used area on the basis of the intensity of the picnic activities. A total of 43 plant species were enumerated in the whole study area. The highest plant species richness (41 species) was observed in the non-used area whereas the lowest species richness (11 species) in the frequently used area. The diversity index decreased with the increase of picnic intensity whereas the concentration of dominance increased. Density of all plant groups except mature trees, and the basal area of the mature trees showed a declining trend from the non-used to frequently used area. The frequently used area exhibited very poor regeneration. Tree vitality decreased with the increase of picnic intensity. The relevance of our study as a basis for further research to determine the impact of tourism on biodiversity in Bangladesh is discussed.
基金Special Research Program “Ecological Regulation of Woody Plant Patterns along Environmental Gradients on Population Dynamic of Key Pine Bark Beetles in Qinling Mountains(2008-11)”the State Forestry Bureau of China
基金co-funded by the EU-funded Zeo LIFE project, European Union (No. LIFE10 ENV/IT/000321)UNIFE young researchers grant 2015+1 种基金the EU-funded Eclaire project, European Union (No. FP7-Env.2011.1.1.2-1 282910)project Nitro Austria, Austrian Climate Research Programme (No. KR14AC7K11916)
文摘Zeolitites (ZTs) are rocks containing more than 50% of zeolite minerals and are known to be a suitable material for agricultural purposes by improving soil physicochemical properties and nitrogen (N) use efficiency. However, little is known about their effects on soil microbial biomass. This study aimed to evaluate short-term effects of different chabazite-rich ZT (CHAZT) amendments on soil microbial biomass and activity. A silty-clay agricultural soil was amended in three different ways, including the addition of natural (5% and 15%) and NH_4^+-enriched (10%) CHAZT. Soil dissolved organic carbon (C), total dissolved N, NH_4^+, NO_3^-, NO_2^-, microbial biomass C and N, and ergosterol were measured periodically over 16 d in a laboratory incubation. To verify the microbial immobilization of the N derived from NH_4^+-enriched CHAZT, a high15N source was used for enriching the mineral to measure the microbial biomass δ15N signature. An increase in the ergosterol content was observed in the soil amended with 5% natural CHAZT. However, no similar result was observed in the soil amended with 15% natural CHAZT, suggesting that the fungal biomass was favored at a lower CHAZT application rate. In the soil amended with NH+ 4-enriched CHAZT, microbial biomass N was related to NO_3^-production over time and inversely related to NH_4^+, suggesting high nitrification process. Isotopic measurements on microbial biomass confirmed immediate assimilation of N derived from NH_4^+-enriched CHAZT. These results suggested that the NH_4^+-enriched CHAZT used in this study supplied an immediately available N pool to the microbial biomass.
文摘Based on the global distribution of land and soil quality and the world population,future trends in the agricultural use of land and soil resources are described,which will severely compromise future global food and fiber production through the increase and the spatial changes of world population,through the loss of fertile land caused by insufficient soil management and through urbanisation and industrialization Moreover,future changes in life style and the increasing demand for food and bioenergy,trough changes in world economy,through climate change and a worldwide decrease in fresh water supply,sustainable land use for the production of food and fiber will be under threat.Until 2050 global food production must be doubled for satisfying global needs.Our scenarios should help to preview future changes,to counterbalance and to mitigate possible negative impacts,thus sustaining global food security.
基金the Austrian Research Promotion Agency(FFG)through the Research Studio Austria FERTI-MINE(No.844744).
文摘Diffusive gradients in thin films(DGT)measurements have been shown to outperform other phosphorus(P)tests in soils with strong P sorption,but this has not been confirmed for moderately weathered European soils.We compared the performance of DGT in predicting wheat grain yield in Swedish long-term fertility experiments with those of standard intensity(water-extractable P(P-H2O))and quantity(ammonium lactate-extractable P(P-AL))tests.A Mitscherlich-type model was used to fit wheat yield response to P application rates(0,15,30 or 35,and 45 kg P ha-1 year-1)in each individual trial replicate to estimate the maximum yield.For trials with clear plateau-type yield responses and the goodness of fit(R2)>0.75,relative yields(RYs)were calculated for each P treatment and plotted against the soil P test results(n=143).The goodness of the Mitscherlich-type fits decreased in the following order:DGT-measured P(P-DGT)(R2=0.35)>P-H2O(R2=0.18)>P-AL(R2=0.13).When excluding soils with P-AL:P-DGT≥0.1 L g-1,R2 was considerably improved to 0.55 for P-AL,0.46 for P-H2O,and 0.65 for P-DGT(n=61).At 95%of maximum yield,the upper limit of P deficiency for P-DGT was 44.8(the soils with P-AL:P-DGT<0.1 L g-1)and 61.9μg L-1(all soils),falling within the range reported for other European and Australian soils(6.0–142μg L-1).We show that in the investigated Swedish soils,DGT performed better than the quantity and intensity tests,which is attributed to its ability to capture P diffusion and resupply from the soil solid phase,similar to plant roots in the rhizosphere.
基金The financial support by the Austrian Science Fund(FWF,project P25870-B16)to WJ is gratefully acknowledgedWe thank Conrad Schoch for providing the matrix of Dothideomycetes,Irmgard Greilhuber and Walter Gams for excursion support and especially R.Rousseaux for collection of AG13137.
文摘During a survey on corticolous Dothideomycetes,several collections with ascospores matching the genera Asteromassaria and Stigmatomassaria(Pleomassariaceae,Pleosporales)were revealed from dead corticated twigs of Acer,Carpinus and Tamarix.Closer morphological examination showed that their ascomata were apothecial,with a hamathecium consisting of septate,branched paraphyses,which are apically swollen at maturity.Several collections were cultured and sequenced,and a Blast search of their nuc 28S rDNA sequences revealed dothideomycetous affiliation,but without a close match to a specific family or order.Phylogenetic analyses of a multigene matrix containing a representative selection of Dothideomycetes from four genes(nuc 18S rDNA,nuc 28S rDNA,rpb2 and tef1)revealed placement within Dothideomycetes but without a supported familial or ordinal affiliation.Based on the phylogenetic analyses and morphological investigations,the new genera Asterodiscus and Stigmatodiscus,with the two new species A.tamaricis and S.enigmaticus,are described and illustrated,and placed in the new family Stigmatodiscaceae and new order Stigmatodiscales.
基金We sincerely thank F.Candoussau,G.Friebes,A.Gardiennet,J.-R.Guu,H.-M.Hsieh,P.Karasch,C.Lechat,M.Pélissier,F.Rappaz and J.D.Rogers for providing specimens,Y.-M.Ju for specimens,cultures and helpful comments on the manuscript,W.Gams for excursion support in Italy,F.Balao,J.Herrera and S.Tello for support and help with determination of fabaceous hosts in Spainthe fungarium curators S.Dominick and E.Roark(BPI),P.Salo(H),B.Aguirre-Hudson(K),N.Sol and G.Thijsse(L),E.Bloch(NY),B.Buyck(PC),A.Freire-Fierro and N.Phillips(PH)for loans and information of specimens,W.Till at WU for sending and managing collections+2 种基金T.Merkx(CBS)for managing our cultures,G.Verkley(CBS)for providing cultures and information about strains of M.rubrumand W.Dämon and I.Greilhuber for insertion of specimens into WU.The financial support by the Austrian Science Fund(FWFproject P25870-B16)is gratefully acknowledged.K.D.Hyde and D.Q.Dai thank the Mae Fah Luang University for the grant BTaxonomy and Phylogeny of selected families of Dothideomycetes(Grant number:56101020032).D.Q.Dai is grateful to the Mushroom Research Foundation,Bandoo,Chiang Rai Province,Thailand,for providing postgraduate scholarship support and thanks the Mae Fah Luang University for the GMS grant.
文摘More than 100 recent collections of Valsaria sensu lato mostly from Europe were used to elucidate the species composition within the genus.Multigene phylogeny based on SSU,LSU,ITS,rpb2 and tef1 sequences revealed a monophyletic group of ten species within the Dothideomycetes,belonging to three morphologically similar genera.This group could not be accommodated in any known family and are thus classified in the new family Valsariaceae and the new order Valsariales.The genus Valsaria sensu stricto comprises V.insitiva,V.robiniae,V.rudis,V.spartii,V.lopadostomoides sp.nov.and V.neotropica sp.nov.,which are phylogenetically well-defined,but morphologically nearly indistinguishable species.The new monotypic genus Bambusaria is introduced to accommodate Valsaria bambusae.Munkovalsaria rubra and Valsaria fulvopruinata are combined in Myrmaecium,a genus traditionally treated as a synonym of Valsaria,which comprises three species,with M.rubricosum as its generic type.This work is presented as a basis for additional species to be detected in future.