Forest ecosystems are important for biodiversity conservation and human societies,but are under pressure due to climate change and human interventions.This applies to natural forests as well as tree plantations.The la...Forest ecosystems are important for biodiversity conservation and human societies,but are under pressure due to climate change and human interventions.This applies to natural forests as well as tree plantations.The latter are globally widespread and therefore gaining increasing importance for biodiversity conservation.However,even after dieback due to increasing disturbance frequencies,such plantations are primarily managed for economic returns,leading to growing conflicts among stakeholders.In particular,the impact of forest management on biodiversity is being discussed.This study investigates the effects of five management approaches in a landscape severely affected by spruce(Picea abies L.)dieback on beetle diversity,conservation,and community composition.We considered direct effects of management and indirect effects of environmental parameters separately in ground-dwelling and flight-active beetles.Beetle diversity was strongly affected by forest management,with nonintervention deadwood stands being most beneficial for beetles.In addition,we show indirect effects of environmental factors.In general,parameters related to salvage logging(e.g.open canopies,tree stumps)influenced beetle diversity and conservation negatively,while positive effects were found for soil nutrient availability and plant species richness.Community composition differed strongly among management categories and indicated a lack of landscape connectivity for open habitat species,as we found only low proportions of such species even on salvage-logged sites.We propose a mixture of management approaches after bark beetle outbreaks,including a substantial proportion of non-intervention deadwood stands,to increase landscape heterogeneity and connectivity.This may increase overall biodiversity while addressing the concerns of both forestry and species conservation.展开更多
Norway spruce(Picea abies(L.)Karst.)in the Harz Mountains National Park(Germany)has experienced widespread mortality(>97%of trees in the study stands)due to infestation with the large spruce bark beetle(Ips typogra...Norway spruce(Picea abies(L.)Karst.)in the Harz Mountains National Park(Germany)has experienced widespread mortality(>97%of trees in the study stands)due to infestation with the large spruce bark beetle(Ips typographus L.).The dead trees(snags)remain standing in the forest for 2-5 years before harvesting.It is important to identify trees that can still produce quality timber,which may be achieved by examining their outer appearance using selected characteristics.The aim of this study was to identify possible correlations between the standing storage duration and defined external characteristics of the snags.The mean tree height at compartment level was calculated using a vegetation height model,based on light detection and ranging data from 2018,to derive the stem breakage proportion.The condition of the crown and the bark and presence of fungi,wood rot,stem cracks and bark stripping damage were also assessed.The majority of the snags were broken at least once.Windthrows were less likely compared to living spruce trees because of reduced resistance to the wind as a result of needle loss and breakage.The mean stem breakage proportion increased significantly with the duration of the standing storage;however,prolonged storage durations did not always lead to complete breakage.The occurrence of fungal fruiting bodies was significantly correlated with a higher proportion of stem breakage,and the longer the storage,the more snags had fungal fruiting bodies.The condition of the crown,assessed by the presence of branchlets,was a good indicator of the duration of the standing storage.If trees had few or no branchlets,they had been standing for at least 4 years.Overall,this initial description of the external appearance of spruce trees that have been stored standing for many years suggests that time significantly influences the tree condition and breakage intensity,which is reflected by certain tree characteristics.Future studies should examine these aspects in greater depth,particularly with regard to utilization options and safety during timber harvesting.展开更多
The 15th China International Animation Copyright Fair concluded successfully at the ACTIF Center in Shipai Town,Dongguan City,also known as the'"Capital of Art Toys in China.n Over 600 Chinese and foreign ent...The 15th China International Animation Copyright Fair concluded successfully at the ACTIF Center in Shipai Town,Dongguan City,also known as the'"Capital of Art Toys in China.n Over 600 Chinese and foreign enterprises and institutions participated in the event,which featured over 2,000 film and animation IPs from more than 40 countries and regions.展开更多
近似数量系统(Approximate Number System,ANS)指个体在不需要依赖于计算和数量符号的情况下,对一组数量进行近似表征的系统。通过总结近十年来研究者们在ANS的遗传和神经基础、干预训练等方面取得的新进展,指出未来应综合运用各种认知...近似数量系统(Approximate Number System,ANS)指个体在不需要依赖于计算和数量符号的情况下,对一组数量进行近似表征的系统。通过总结近十年来研究者们在ANS的遗传和神经基础、干预训练等方面取得的新进展,指出未来应综合运用各种认知神经科学研究手段立足于ANS的基因和脑生理基础研究,进一步揭示ANS的本质和内在发生发展机制,并将有关研究发现运用到教育教学中,对数学困难儿童进行干预,以提高其数学能力和适应社会的能力。展开更多
基金supported by Forschungsanstalt für Waldo kologie und Forstwirtschaft(FAWF)of Landesforsten Rheinland-Pfalz(FF 5.3-01-2021)。
文摘Forest ecosystems are important for biodiversity conservation and human societies,but are under pressure due to climate change and human interventions.This applies to natural forests as well as tree plantations.The latter are globally widespread and therefore gaining increasing importance for biodiversity conservation.However,even after dieback due to increasing disturbance frequencies,such plantations are primarily managed for economic returns,leading to growing conflicts among stakeholders.In particular,the impact of forest management on biodiversity is being discussed.This study investigates the effects of five management approaches in a landscape severely affected by spruce(Picea abies L.)dieback on beetle diversity,conservation,and community composition.We considered direct effects of management and indirect effects of environmental parameters separately in ground-dwelling and flight-active beetles.Beetle diversity was strongly affected by forest management,with nonintervention deadwood stands being most beneficial for beetles.In addition,we show indirect effects of environmental factors.In general,parameters related to salvage logging(e.g.open canopies,tree stumps)influenced beetle diversity and conservation negatively,while positive effects were found for soil nutrient availability and plant species richness.Community composition differed strongly among management categories and indicated a lack of landscape connectivity for open habitat species,as we found only low proportions of such species even on salvage-logged sites.We propose a mixture of management approaches after bark beetle outbreaks,including a substantial proportion of non-intervention deadwood stands,to increase landscape heterogeneity and connectivity.This may increase overall biodiversity while addressing the concerns of both forestry and species conservation.
基金supported by the German Federal Ministry of Food and Agriculture(BMEL)and the German Federal Ministry for the Environment,Nature Conservation,Nuclear Safety and Consumer Protection(BMUV)via the Agency for Renewable Resources(FNR)(GRANT no.2220WK49E3)。
文摘Norway spruce(Picea abies(L.)Karst.)in the Harz Mountains National Park(Germany)has experienced widespread mortality(>97%of trees in the study stands)due to infestation with the large spruce bark beetle(Ips typographus L.).The dead trees(snags)remain standing in the forest for 2-5 years before harvesting.It is important to identify trees that can still produce quality timber,which may be achieved by examining their outer appearance using selected characteristics.The aim of this study was to identify possible correlations between the standing storage duration and defined external characteristics of the snags.The mean tree height at compartment level was calculated using a vegetation height model,based on light detection and ranging data from 2018,to derive the stem breakage proportion.The condition of the crown and the bark and presence of fungi,wood rot,stem cracks and bark stripping damage were also assessed.The majority of the snags were broken at least once.Windthrows were less likely compared to living spruce trees because of reduced resistance to the wind as a result of needle loss and breakage.The mean stem breakage proportion increased significantly with the duration of the standing storage;however,prolonged storage durations did not always lead to complete breakage.The occurrence of fungal fruiting bodies was significantly correlated with a higher proportion of stem breakage,and the longer the storage,the more snags had fungal fruiting bodies.The condition of the crown,assessed by the presence of branchlets,was a good indicator of the duration of the standing storage.If trees had few or no branchlets,they had been standing for at least 4 years.Overall,this initial description of the external appearance of spruce trees that have been stored standing for many years suggests that time significantly influences the tree condition and breakage intensity,which is reflected by certain tree characteristics.Future studies should examine these aspects in greater depth,particularly with regard to utilization options and safety during timber harvesting.
文摘The 15th China International Animation Copyright Fair concluded successfully at the ACTIF Center in Shipai Town,Dongguan City,also known as the'"Capital of Art Toys in China.n Over 600 Chinese and foreign enterprises and institutions participated in the event,which featured over 2,000 film and animation IPs from more than 40 countries and regions.
文摘近似数量系统(Approximate Number System,ANS)指个体在不需要依赖于计算和数量符号的情况下,对一组数量进行近似表征的系统。通过总结近十年来研究者们在ANS的遗传和神经基础、干预训练等方面取得的新进展,指出未来应综合运用各种认知神经科学研究手段立足于ANS的基因和脑生理基础研究,进一步揭示ANS的本质和内在发生发展机制,并将有关研究发现运用到教育教学中,对数学困难儿童进行干预,以提高其数学能力和适应社会的能力。
