Conversion of natural forests into pure plantation forests is a common management practice in subtropical China.To evaluate the effects of forest conversion on soil fertility, microbe numbers and enzyme activities in ...Conversion of natural forests into pure plantation forests is a common management practice in subtropical China.To evaluate the effects of forest conversion on soil fertility, microbe numbers and enzyme activities in topsoils (0-10 cm)were quantified in two 33-year-old monoculture plantations of Castanopsis kawakamii Hayata (CK) and Cunninghamia lanceolata Lamb. (Chinese fir) (CF), and compared to a neighboring relict natural C. kawakamii forest (NF), in Sanming,Fujian. Five soil samples were collected once each in January, April, July, September and November in 2000 in each forest for laboratory analysis. Over the sampling year, there were significant differences for bacteria, fungi and actinomycetes between forests and between seasons (P ＜ 0.05). The largest bacteria and fungi populations were in NF, while CF contained the greatest number of actinomycetes. There were also significant differences (P ＜ 0.05) with microbial respiration for forests and seasons. Additionally, compared with NF, urease and acid phosphatase were significantly lower (P ＜ 0.05)in CK and CF. Also, the correlations of soil hydrolysable N and available P to soil microbial and enzymatic activities were highly significant (P ＜ 0.01). Thus, to alter the traditional Chinese fir monoculture so as to mimic the natural forest conditions, managing mixed stands of Chinese fir and broadleaf trees or conducting crop rotation of conifers and broadleaf trees as well as minimizing forest disturbances like clear-cutting, slash burning and soil preparing, could be utilized.展开更多
The impact of human activity on biodiversity is very complicated, making it difficult to design practical indicators for assessment.Currently,state and response indicators are listed within Chapter15 of Agenda21,but n...The impact of human activity on biodiversity is very complicated, making it difficult to design practical indicators for assessment.Currently,state and response indicators are listed within Chapter15 of Agenda21,but no mention is made of driving force indicators and how they relate to biodiversity protection. This paper repre- sents an effort to identify and then operationalize the idea of driving force indicators at national level.Five human induced factors affecting biodiversity were discussed: (a) habitat loss and fragmentation; (b) overexploitation of resources;(c)species introduction;(d)pollution;and (e) climate change. From these five factors, a subsetwas selected to serve as possible driving force indicators:(1)habitat loss, (2)the ratio of exotic species to indigenous ones, and (3)the change in pollution status. Although the three indicators are relatively simple,they coverthe most important human impacts on biodiversity and offer the potential for further redefinition and ultimate use within the spirit of biodiversity protection.展开更多
Biological ion channels show that ultrafast ions and molecules transmission are in a quantum way of single molecular or ionic chain with a certain number of molecules or ions, and we define it as ＂quantum-confined su...Biological ion channels show that ultrafast ions and molecules transmission are in a quantum way of single molecular or ionic chain with a certain number of molecules or ions, and we define it as ＂quantum-confined superfluid＂ （QSF）. This ordered ultrafast flow in the confined channel can be considered as ＂quantum tunneling fluid effect＂ with a ＂tunneling distance＂, which is corresponding to the period of QSF. Recent research demonstrated that artificial biomimetic nanochannels also showed the phenomenon of QSF, such as ion and water channels. The introduction of QSF concept in the fields of chemistry and biology may create significant impact. As for chemistry, the QSF effect provides new ideas for accurate synthesis in organic, inorganic, polymer, etc. We believe the implementation of the idea of QSF will promote the development of QSF biochemistry, biophysics, bioinformatics and biomedical science.展开更多
基金the Basic Research Program of Fujian Province (No. 2000-F-004).
文摘Conversion of natural forests into pure plantation forests is a common management practice in subtropical China.To evaluate the effects of forest conversion on soil fertility, microbe numbers and enzyme activities in topsoils (0-10 cm)were quantified in two 33-year-old monoculture plantations of Castanopsis kawakamii Hayata (CK) and Cunninghamia lanceolata Lamb. (Chinese fir) (CF), and compared to a neighboring relict natural C. kawakamii forest (NF), in Sanming,Fujian. Five soil samples were collected once each in January, April, July, September and November in 2000 in each forest for laboratory analysis. Over the sampling year, there were significant differences for bacteria, fungi and actinomycetes between forests and between seasons (P ＜ 0.05). The largest bacteria and fungi populations were in NF, while CF contained the greatest number of actinomycetes. There were also significant differences (P ＜ 0.05) with microbial respiration for forests and seasons. Additionally, compared with NF, urease and acid phosphatase were significantly lower (P ＜ 0.05)in CK and CF. Also, the correlations of soil hydrolysable N and available P to soil microbial and enzymatic activities were highly significant (P ＜ 0.01). Thus, to alter the traditional Chinese fir monoculture so as to mimic the natural forest conditions, managing mixed stands of Chinese fir and broadleaf trees or conducting crop rotation of conifers and broadleaf trees as well as minimizing forest disturbances like clear-cutting, slash burning and soil preparing, could be utilized.
文摘The impact of human activity on biodiversity is very complicated, making it difficult to design practical indicators for assessment.Currently,state and response indicators are listed within Chapter15 of Agenda21,but no mention is made of driving force indicators and how they relate to biodiversity protection. This paper repre- sents an effort to identify and then operationalize the idea of driving force indicators at national level.Five human induced factors affecting biodiversity were discussed: (a) habitat loss and fragmentation; (b) overexploitation of resources;(c)species introduction;(d)pollution;and (e) climate change. From these five factors, a subsetwas selected to serve as possible driving force indicators:(1)habitat loss, (2)the ratio of exotic species to indigenous ones, and (3)the change in pollution status. Although the three indicators are relatively simple,they coverthe most important human impacts on biodiversity and offer the potential for further redefinition and ultimate use within the spirit of biodiversity protection.
基金supported by the National Key R&D Program of China(2017YFA0206900)the National Natural Science Foundation of China(21625303)
文摘Biological ion channels show that ultrafast ions and molecules transmission are in a quantum way of single molecular or ionic chain with a certain number of molecules or ions, and we define it as ＂quantum-confined superfluid＂ （QSF）. This ordered ultrafast flow in the confined channel can be considered as ＂quantum tunneling fluid effect＂ with a ＂tunneling distance＂, which is corresponding to the period of QSF. Recent research demonstrated that artificial biomimetic nanochannels also showed the phenomenon of QSF, such as ion and water channels. The introduction of QSF concept in the fields of chemistry and biology may create significant impact. As for chemistry, the QSF effect provides new ideas for accurate synthesis in organic, inorganic, polymer, etc. We believe the implementation of the idea of QSF will promote the development of QSF biochemistry, biophysics, bioinformatics and biomedical science.
