This review gives a brief retrospect to the development on in vitro fertilization (IVF) of angiosperms in China. During the last decade Chinese scientists put great enthusiasm and efforts on IVF system construction an...This review gives a brief retrospect to the development on in vitro fertilization (IVF) of angiosperms in China. During the last decade Chinese scientists put great enthusiasm and efforts on IVF system construction and built up notable contributions to the flourish of this field. Keeping pace with international development and participating international cooperation in the field of IVF, Chinese scientists have now focused on the investigation of basic mechanism relevant to possible gamete interaction, egg cell activation and early embryogenesis by IVF. In vitro manipulation techniques are combined with cytological and molecular biological approaches to unveil the double fertilization mysteries.展开更多
An exploratory survey was conducted on the uses and role of invasive alien species(IAS) to local livelihoods in the Rema-Kalenga Wildlife Sanctuary in the northeastern hilly region of Bangladesh.Vegetation was sampled...An exploratory survey was conducted on the uses and role of invasive alien species(IAS) to local livelihoods in the Rema-Kalenga Wildlife Sanctuary in the northeastern hilly region of Bangladesh.Vegetation was sampled in 50 quadrates,each 10 m×10 m,and 25 line transects,each 50 m×20 m,through a combination of random and systematic sampling.Group discussions were also arranged with fifty local inhabitants(17 % of the total inhabitants) to learn the various uses of IAS.A total of 17 alien plant species belonging to 10 different families,of which Leguminosae constitutes the highest number(5 species),include tree(53%) followed by herb(12%),shrub(12%) and others(weed,climber and palm).The majority of the identified species were found to be used for fuel,followed by timber production,medicinal or curative uses,fodder,and many others.In addition to providing various forest products,alien tree species planted in forest plantation help provide many vital ecosystem services such as soil amelioration through nitrogen fixation.It is true that the alien species have some negative impacts on local ecosystems,and not all of them are harmful.Therefore,a national programme must be initiated to distinguish the harmful from the harmless species and to identify the uses and impacts of the former and latter.展开更多
Aims Alien plant invasion has become a major global environmental issue,causing severe economic and ecological damages.Severe invasions have been reported in some regions of China.However,most studies have been conduc...Aims Alien plant invasion has become a major global environmental issue,causing severe economic and ecological damages.Severe invasions have been reported in some regions of China.However,most studies have been conducted at local and provincial levels,and the overall degree of invasion in natural forests across China remains unclear.Here,we explored the biogeographic patterns and their environmental and socioeconomic controls of the invaded alien woody plants in natural forests across the country.Methods We compiled the data of 3573 natural forest plots across the China's Mainland and mapped spatial distribution of alien woody plant invasion.We also used logistic regression models to identify the key socioeconomic and environmental factors that were associated with the observed invasion patterns.Important Findings We found that only 271 plots among 3573 natural forest plots were invaded by alien woody plants,accounting for 7.58%of all plots.Among all 2825 woody plant species across all plots surveyed,only 5 alien species(0.177%)were found.Both human activities and climate factors were related to the observed invasion patterns.Since China’s natural forests are mostly located in remote mountainous areas with limited human disturbance,alien woody plant invasions are less than those reported in North America and Europe.However,with the development of transportation and increased economic activities in mountainous areas,more invasions by alien plants may be expected in the future.Therefore,proactive management and policy making are desired to prevent or slow down the invasion processes.展开更多
文摘This review gives a brief retrospect to the development on in vitro fertilization (IVF) of angiosperms in China. During the last decade Chinese scientists put great enthusiasm and efforts on IVF system construction and built up notable contributions to the flourish of this field. Keeping pace with international development and participating international cooperation in the field of IVF, Chinese scientists have now focused on the investigation of basic mechanism relevant to possible gamete interaction, egg cell activation and early embryogenesis by IVF. In vitro manipulation techniques are combined with cytological and molecular biological approaches to unveil the double fertilization mysteries.
文摘An exploratory survey was conducted on the uses and role of invasive alien species(IAS) to local livelihoods in the Rema-Kalenga Wildlife Sanctuary in the northeastern hilly region of Bangladesh.Vegetation was sampled in 50 quadrates,each 10 m×10 m,and 25 line transects,each 50 m×20 m,through a combination of random and systematic sampling.Group discussions were also arranged with fifty local inhabitants(17 % of the total inhabitants) to learn the various uses of IAS.A total of 17 alien plant species belonging to 10 different families,of which Leguminosae constitutes the highest number(5 species),include tree(53%) followed by herb(12%),shrub(12%) and others(weed,climber and palm).The majority of the identified species were found to be used for fuel,followed by timber production,medicinal or curative uses,fodder,and many others.In addition to providing various forest products,alien tree species planted in forest plantation help provide many vital ecosystem services such as soil amelioration through nitrogen fixation.It is true that the alien species have some negative impacts on local ecosystems,and not all of them are harmful.Therefore,a national programme must be initiated to distinguish the harmful from the harmless species and to identify the uses and impacts of the former and latter.
基金This research was supported by the National Natural Science Foundation of China(31988102).
文摘Aims Alien plant invasion has become a major global environmental issue,causing severe economic and ecological damages.Severe invasions have been reported in some regions of China.However,most studies have been conducted at local and provincial levels,and the overall degree of invasion in natural forests across China remains unclear.Here,we explored the biogeographic patterns and their environmental and socioeconomic controls of the invaded alien woody plants in natural forests across the country.Methods We compiled the data of 3573 natural forest plots across the China's Mainland and mapped spatial distribution of alien woody plant invasion.We also used logistic regression models to identify the key socioeconomic and environmental factors that were associated with the observed invasion patterns.Important Findings We found that only 271 plots among 3573 natural forest plots were invaded by alien woody plants,accounting for 7.58%of all plots.Among all 2825 woody plant species across all plots surveyed,only 5 alien species(0.177%)were found.Both human activities and climate factors were related to the observed invasion patterns.Since China’s natural forests are mostly located in remote mountainous areas with limited human disturbance,alien woody plant invasions are less than those reported in North America and Europe.However,with the development of transportation and increased economic activities in mountainous areas,more invasions by alien plants may be expected in the future.Therefore,proactive management and policy making are desired to prevent or slow down the invasion processes.
