The community characteristics of natural secondary forests on the north slope of Changbai Mountain after selective cutting were investigated, and the dynamics of arborous species diversity during the restoration perio...The community characteristics of natural secondary forests on the north slope of Changbai Mountain after selective cutting were investigated, and the dynamics of arborous species diversity during the restoration period of 28 years were studied. The results showed that the arborous species richness (S) had little change and kept the range of 18-22 all along, the Simpson index (D) of the secondary layer and regeneration layer and whole stand had similar trends of change, but that of the canopy layer descended slowly in initial 15 years and had little change later, and the change of diversity index was not obvious and the Shannon-Wiener index (H? fluctuated in a very small scopes (H±10%).展开更多
The structure and principle of the PMAC (Programmable Multi-Axis Controller) were described.The implementation of PMAC hardware was illustrated by taking the winding process of one cell for example.The main obvious ch...The structure and principle of the PMAC (Programmable Multi-Axis Controller) were described.The implementation of PMAC hardware was illustrated by taking the winding process of one cell for example.The main obvious character of PMAC is to complete a movement program in turns of movement sequence.When PMAC is notified to execute a motion program, it will process one command every time and finish all the calculation to be ready for real action.PMAC card works always prior to real action, when necessary, it can always coordinate correctly with the action which will be carried out soon PMAC will automatically carry out the function of resource management periodically to make sure that the whole system is in correct condition.And also, it can communicate with host computer anytime even during a movement series.The responsibility of PMAC is to organize command according to priority to optimize the system, so as to run the application program safely and efficiently.The function and application of control were emphasized.展开更多
In the urbanized territory (the Irkutsk city), the content of sulfur and heavy metals (lead, cadmium, copper, zinc) in soil profile horizons and leaves (needles) arboreal plants were studied. High accumulation of poll...In the urbanized territory (the Irkutsk city), the content of sulfur and heavy metals (lead, cadmium, copper, zinc) in soil profile horizons and leaves (needles) arboreal plants were studied. High accumulation of polluting elements in pine and larch needles, birch and poplar leaves, as well as in all genetic horizons of the city soils was shown. There were revealed elements disbalance in city trees assimilation organs showing in the increase of the polluting elements quota with the parallel decrease of the quota of nitrogen, phosphorus, calcium, magnesium, potassium, manganese. Pollutants concentration in trees needles (leaves) was shown to be closely related to their content in soil horizons. The results speak in favor of high migration ability of polluting elements in soil profile and about possibility their entrance in trees root system and further to assimilation organs from all city soils horizons. It can be concluded that data on accumulation and migration of polluting elements in soils and arboreal trees assimilation organs contribute to adequate assessment of technogenic load on urban ecosystems.展开更多
A linear forest is a forest whose components are paths. The linear arboricity la （G） of a graph G is the minimum number of linear forests which partition the edge set E（G） of G. The Cartesian product G□H of two g...A linear forest is a forest whose components are paths. The linear arboricity la （G） of a graph G is the minimum number of linear forests which partition the edge set E（G） of G. The Cartesian product G□H of two graphs G and H is defined as the graph with vertex set V（G□H） = {（u, v）｜ u ∈V（G）, v∈V（H） } and edge set E（G□H） = { （ u, x） （ v, Y）｜u=v and xy∈E（H）, or uv∈E（G） and x=y}. Let Pm and Cm,, respectively, denote the path and cycle on m vertices and K, denote the complete graph on n vertices. It is proved that （Km□Pm）=[n＋1/2]for m≥2,la（Km□Cm）=[n＋2/2],and la（Km□Km）=[n＋m-1/2]. The methods to decompose these graphs into linear forests are given in the proofs. Furthermore, the linear arboricity conjecture is true for these classes of graphs.展开更多
For a long time,forestry primarily had industrial goals.Volume of wood production was the main criterion of forestry efficacy,and thus rapid-growing arboreal species were cultivated in natural forests.More recently,na...For a long time,forestry primarily had industrial goals.Volume of wood production was the main criterion of forestry efficacy,and thus rapid-growing arboreal species were cultivated in natural forests.More recently,nature protection has become one of forestry＇s goals.Unfortunately,some introduced,rapid-growing species became aggressive components of natural ecological systems during the interim.In this paper,we first describe a method that we developed to categorize aggressiveness of invasive arboreal plants in natural forest ecosystems of Kazakhstan.We then apply this new scheme to monitoring data of invasive arboreal plants to provide an insight into the invasion potential of different species in the fruit forests of Southeast Kazakhstan.展开更多
Indian Giant Flying Squirrel(Petaurista philippensis Elliot 1839)is widely distributed in South Asia and the only species of flying squirrel found in Gujarat.We studied the seasonal variation in its feeding behaviour ...Indian Giant Flying Squirrel(Petaurista philippensis Elliot 1839)is widely distributed in South Asia and the only species of flying squirrel found in Gujarat.We studied the seasonal variation in its feeding behaviour at selected sites of Central Gujarat.Focal sampling was employed to study the behaviours and mainly feeding behaviours.Feeding analyses were consistent with other studies and indicated Madhuca longifolia as an important food resource.The diet of the species mainly consisted of pith,twig,seed,bark,petiole,young to mature leaves,flower and fruits of 20 species of plants of 15 families along with lichens,Vanda tessellata and Dendrophthoe falcata.Madhuca longifolia(25%)contributed most to the squirrel diet,followed by Diospyros melanoxylon(10%)and Terminalia tomentosa(9%).Among the plant parts consumed,pith formed the highest bulk as a food at 23%,followed by fruits(21%),bark(16%),twig(14%),flower(10%),seed(6%),leaf(6%),and bud(4%).The findings reveal the high dependency of flying squirrel on certain tree species.These tree species are well represented and distributed throughout central Gujarat,indicating that this area is important for the survival of this species and that the area should be conserved for protection and future management of this species.展开更多
Pine wilt disease caused by pine wood nema-todes is a deadly disease of the genus Pinus requiring strong quarantine measures.Since its discovery,it has been widely distributed throughout the world.China is one of the ...Pine wilt disease caused by pine wood nema-todes is a deadly disease of the genus Pinus requiring strong quarantine measures.Since its discovery,it has been widely distributed throughout the world.China is one of the coun-tries with a severe rate of infections due to its abundant pine resources.In this study,nematode-trapping fungi were collected from pine trees in Ninghai City,Zhejiang Prov-ince,which is the key area of pine wilt control in Febru-ary,May,September,October and November.The results showed that nematode-trapping fungi of pine are abundant,especially the number and species detected in each month and are quite different;species of fungi in July,Septem-ber and November were more numerous and had higher separation rates.The dominant species in November was Arthrobotrys oligospora followed by Arthrobotrys cladodes;July and September it was A.cladodes.In each part of the tree,A.cladodes was the most widely distributed with a high separation rate.Therefore,it is the dominant fungal species in the area.Arboreal Bursaphelenchus xylophilus-trapping fungi are dependent on pine wood nematodes,and none were isolated from healthy pine trees.More arboreal B.xylophilus-trapping fungi were found under the bark than in the xylem.There is a close relationship between arboreal B.xylophilus-trapping fungi and pine wood nematodes.How to make use of these resources to reduce the damage of pine wood nematode fusarium is the focus of future research.展开更多
In this paper, secondary forest of Pinus massoniana , coniferous-broad-leaved mixed forest and broad-leaved evergreen forest were taken as research objects, to explore carbon reserve of arbor layer and its spatial dis...In this paper, secondary forest of Pinus massoniana , coniferous-broad-leaved mixed forest and broad-leaved evergreen forest were taken as research objects, to explore carbon reserve of arbor layer and its spatial distribution characteristics. At different succession stages, the sequence of organic carbon content in each organ was secondary forest of P. massoniana > coniferous-broad-leaved mixed forest> broad-leaved evergreen forest. Carbon reserve of arbor layer was the highest in broad-leaved evergreen forest, which was 129.34 t/hm 2, followed by coniferous-broad-leaved mixed forest (95.83 t/hm 2), and the minimum was 85.27 t/hm 2 in secondary forest of P. massoniana . In each stand type, the sequence of carbon reserve of each organ in arbor layer was trunk>root>branch>leaf>bark. Carbon reserve of arbor layer mainly concentrated in trunk, and the proportion to carbon reserve of arbor layer declined from secondary forest of P. massoniana to broad-leaved evergreen forest, while it had increasing relationship in root. In secondary forest of P. massoniana , coniferous-broad-leaved mixed forest and broad-leaved evergreen forest, individual with the diameter more than 20 cm accounted for the majority of carbon reserve in the arbor layer.展开更多
基金This research was supported by Institute of Shenyang Applied Ecology CAS (SCXMS0101),National Key Technologies R&D Program (NKTRDP. 2002BA516A20) and the Scientific Research Foundation for the Returned Overseas Chinese Scholars, Ministry of Education
文摘The community characteristics of natural secondary forests on the north slope of Changbai Mountain after selective cutting were investigated, and the dynamics of arborous species diversity during the restoration period of 28 years were studied. The results showed that the arborous species richness (S) had little change and kept the range of 18-22 all along, the Simpson index (D) of the secondary layer and regeneration layer and whole stand had similar trends of change, but that of the canopy layer descended slowly in initial 15 years and had little change later, and the change of diversity index was not obvious and the Shannon-Wiener index (H? fluctuated in a very small scopes (H±10%).
文摘The structure and principle of the PMAC (Programmable Multi-Axis Controller) were described.The implementation of PMAC hardware was illustrated by taking the winding process of one cell for example.The main obvious character of PMAC is to complete a movement program in turns of movement sequence.When PMAC is notified to execute a motion program, it will process one command every time and finish all the calculation to be ready for real action.PMAC card works always prior to real action, when necessary, it can always coordinate correctly with the action which will be carried out soon PMAC will automatically carry out the function of resource management periodically to make sure that the whole system is in correct condition.And also, it can communicate with host computer anytime even during a movement series.The responsibility of PMAC is to organize command according to priority to optimize the system, so as to run the application program safely and efficiently.The function and application of control were emphasized.
文摘In the urbanized territory (the Irkutsk city), the content of sulfur and heavy metals (lead, cadmium, copper, zinc) in soil profile horizons and leaves (needles) arboreal plants were studied. High accumulation of polluting elements in pine and larch needles, birch and poplar leaves, as well as in all genetic horizons of the city soils was shown. There were revealed elements disbalance in city trees assimilation organs showing in the increase of the polluting elements quota with the parallel decrease of the quota of nitrogen, phosphorus, calcium, magnesium, potassium, manganese. Pollutants concentration in trees needles (leaves) was shown to be closely related to their content in soil horizons. The results speak in favor of high migration ability of polluting elements in soil profile and about possibility their entrance in trees root system and further to assimilation organs from all city soils horizons. It can be concluded that data on accumulation and migration of polluting elements in soils and arboreal trees assimilation organs contribute to adequate assessment of technogenic load on urban ecosystems.
基金The National Natural Science Foundation of China(No.10971025)
文摘A linear forest is a forest whose components are paths. The linear arboricity la （G） of a graph G is the minimum number of linear forests which partition the edge set E（G） of G. The Cartesian product G□H of two graphs G and H is defined as the graph with vertex set V（G□H） = {（u, v）｜ u ∈V（G）, v∈V（H） } and edge set E（G□H） = { （ u, x） （ v, Y）｜u=v and xy∈E（H）, or uv∈E（G） and x=y}. Let Pm and Cm,, respectively, denote the path and cycle on m vertices and K, denote the complete graph on n vertices. It is proved that （Km□Pm）=[n＋1/2]for m≥2,la（Km□Cm）=[n＋2/2],and la（Km□Km）=[n＋m-1/2]. The methods to decompose these graphs into linear forests are given in the proofs. Furthermore, the linear arboricity conjecture is true for these classes of graphs.
文摘For a long time,forestry primarily had industrial goals.Volume of wood production was the main criterion of forestry efficacy,and thus rapid-growing arboreal species were cultivated in natural forests.More recently,nature protection has become one of forestry＇s goals.Unfortunately,some introduced,rapid-growing species became aggressive components of natural ecological systems during the interim.In this paper,we first describe a method that we developed to categorize aggressiveness of invasive arboreal plants in natural forest ecosystems of Kazakhstan.We then apply this new scheme to monitoring data of invasive arboreal plants to provide an insight into the invasion potential of different species in the fruit forests of Southeast Kazakhstan.
基金Wildlife and Conservation Biology Research Lab,HNG University
文摘Indian Giant Flying Squirrel(Petaurista philippensis Elliot 1839)is widely distributed in South Asia and the only species of flying squirrel found in Gujarat.We studied the seasonal variation in its feeding behaviour at selected sites of Central Gujarat.Focal sampling was employed to study the behaviours and mainly feeding behaviours.Feeding analyses were consistent with other studies and indicated Madhuca longifolia as an important food resource.The diet of the species mainly consisted of pith,twig,seed,bark,petiole,young to mature leaves,flower and fruits of 20 species of plants of 15 families along with lichens,Vanda tessellata and Dendrophthoe falcata.Madhuca longifolia(25%)contributed most to the squirrel diet,followed by Diospyros melanoxylon(10%)and Terminalia tomentosa(9%).Among the plant parts consumed,pith formed the highest bulk as a food at 23%,followed by fruits(21%),bark(16%),twig(14%),flower(10%),seed(6%),leaf(6%),and bud(4%).The findings reveal the high dependency of flying squirrel on certain tree species.These tree species are well represented and distributed throughout central Gujarat,indicating that this area is important for the survival of this species and that the area should be conserved for protection and future management of this species.
基金The work was supported by the Fundamental Research Funds for the Central University(No.2572020DY11).
文摘Pine wilt disease caused by pine wood nema-todes is a deadly disease of the genus Pinus requiring strong quarantine measures.Since its discovery,it has been widely distributed throughout the world.China is one of the coun-tries with a severe rate of infections due to its abundant pine resources.In this study,nematode-trapping fungi were collected from pine trees in Ninghai City,Zhejiang Prov-ince,which is the key area of pine wilt control in Febru-ary,May,September,October and November.The results showed that nematode-trapping fungi of pine are abundant,especially the number and species detected in each month and are quite different;species of fungi in July,Septem-ber and November were more numerous and had higher separation rates.The dominant species in November was Arthrobotrys oligospora followed by Arthrobotrys cladodes;July and September it was A.cladodes.In each part of the tree,A.cladodes was the most widely distributed with a high separation rate.Therefore,it is the dominant fungal species in the area.Arboreal Bursaphelenchus xylophilus-trapping fungi are dependent on pine wood nematodes,and none were isolated from healthy pine trees.More arboreal B.xylophilus-trapping fungi were found under the bark than in the xylem.There is a close relationship between arboreal B.xylophilus-trapping fungi and pine wood nematodes.How to make use of these resources to reduce the damage of pine wood nematode fusarium is the focus of future research.
基金Sponsored by Forestry Science and Technology Plan of Hunan Province(XLK201806,XLK201925)National Forestry Science and Technology Development Project(KJZXSA2018011,KJZXSA2019009)Operational Subsidy Project of National Forestry Science and Technology Innovation Platform(2019132068)
文摘In this paper, secondary forest of Pinus massoniana , coniferous-broad-leaved mixed forest and broad-leaved evergreen forest were taken as research objects, to explore carbon reserve of arbor layer and its spatial distribution characteristics. At different succession stages, the sequence of organic carbon content in each organ was secondary forest of P. massoniana > coniferous-broad-leaved mixed forest> broad-leaved evergreen forest. Carbon reserve of arbor layer was the highest in broad-leaved evergreen forest, which was 129.34 t/hm 2, followed by coniferous-broad-leaved mixed forest (95.83 t/hm 2), and the minimum was 85.27 t/hm 2 in secondary forest of P. massoniana . In each stand type, the sequence of carbon reserve of each organ in arbor layer was trunk>root>branch>leaf>bark. Carbon reserve of arbor layer mainly concentrated in trunk, and the proportion to carbon reserve of arbor layer declined from secondary forest of P. massoniana to broad-leaved evergreen forest, while it had increasing relationship in root. In secondary forest of P. massoniana , coniferous-broad-leaved mixed forest and broad-leaved evergreen forest, individual with the diameter more than 20 cm accounted for the majority of carbon reserve in the arbor layer.
