BIOLOGICAL INVASION PROBLEM WITH FREE BOUNDARY NONLOCAL DIFFUSION EQUATION

In order to better describe the phenomenon of biological invasion,this paper introduces a free boundary model of biological invasion.Firstly,the right free boundary is added to the equation with logistic terms.Secondly,the existence and uniqueness of local solutions are proved by the Sobolev embedding theorem and the comparison principle.Finally,according to the relevant research data and contents of red fire ants,the diffusion area and nest number of red fire ants were simulated without external disturbance.This paper mainly simulates the early diffusion process of red fire ants.In the early diffusion stage,red fire ants grow slowly and then spread over a large area after reaching a certain number.

Study on the Biological Diversity of Nematode-trapping Fungi in Erhai Lake

[Objective]The research aimed to investigate the biological diversity of nematode-trapping fungi in the sediment of Erhai Lake.[Method]616 pieces of sediments were collected from Erhai Lake.The traditional classification and identification methods were used to isolate,purify and identify.[Result]3 genera and 22 species of nematode-trapping fungi were isolated.Arthrobotrys oligospora,A.musiformis and Dactylella leptospora were the dominant species,and their detection rates were 28.05%,16.04% and 8.92% respectively.By analyzing the diversity of nematode-trapping fungi in four seasons,it was found that the biological diversity was richer in summer,spring and autumn,and the diversity indexes were 2.59,2.47 and 2.34 respectively.The diversity index in winter was 1.48 and was lower.Species forming the adhesive nets were predominant;positive rate was 41.00%.[Conclusion]The rich nematode-trapping fungi resource existed in Erhai Lake,and its biological diversity had the seasonal variation characteristic.The nematode-trapping fungi which formed the viscous net were the dominant species in Erhai Lake.

Study on Mosuo's Sacred Natural Sites of Mountainous Forest and Protection of Biological Diversity in Yongning-Lugu Lake Area

With Mosuo's sacred natural sites of mountainous forest in Yongning-Lugu Lake area as the research subject,by using the method of ecology,the vegetation type in this area was initially identified.The control sample plot of the same vegetation type at similar altitude and in similar soil condition would be selected and compared with the sample plot in sacred natural sites at length,so as to quantitatively analyze the protection of biological diversity in the perspective of ecological system.It showed that under the circumstance of the damage of ecological environment,complete natural vertical pattern was preserved thanks to sacred natural sites of mountainous forest established by reason of traditional religion and culture.The results of research and quantitative analysis showed that compared with the control sample plot of the same vegetation type,sacred natural sites were high in biological diversity and the species composition of plant community in sacred natural sites was closer to that of primitive forest.The result of quantitative analysis also indicated that sacred natural sites played a remarkable role in protecting vegetation and this protective function became more remarkable if the altitude was higher.And human were reminded to pay close attention to the preservation and protection function of sacred natural sites to natural ecological system at high altitude.

Biological and cultural diversity in the context of botanic garden conservation strategies

Impacts of global climate change, habitat loss, and other environmental changes on the world's biota and peoples continue to increase, especially on islands and in high elevation areas. Just as floristic diversity is affected by environmental change, so too are cultural and linguistic diversity. Of the approximately 7000 extant languages in the world, fully 50% are considered to be at risk of extinction, which is considerably higher than most estimates of extinction risks to plants and animals. To maintain the integrity of plant life, it is not enough for botanic gardens to consider solely the effects of environmental change on plants within the context of major conservation strategies such as the Global Strategy for Plant Conservation and the Convention on Biological Diversity. Rather, botanic gardens should actively engage in understanding and communicating the broader impacts of environmental change to biological and cultural diversity.

Research on the implementation of the Convention on Biological Diversity among the Shanghai Cooperation Organisation countries

The Shanghai Cooperation Organisation(SCO)is the most extensive and populous comprehensive regional cooperation organization in the world,covering about half of the world's population,with not only a huge consumer market,but also rich natural resources and strong productivity.As one of the important platforms for the implementation of the Green Belt and Road Initiative,it is an important opportunity for the SCO to actively participate in global governance and contribute to building a community of global life.To investigate the status of biodiversity conservation in the SCO countries,we used literature analysis approach.We surveyed the performance and international cooperation status of the SCO countries in the implementation of the Convention on Biological Diversity(CBD),listed facing problems and threats to biodiversity conservation,including not optimistic biodiversity conservation project implementation status,contradiction between ecological protection and economic development,impacts of human activities,lack of funds and talents,etc.,and analyzed the biodiversity protection needs of the SCO countries from the perspectives of project and policy implementation status and international cooperation.According to the cooperation between China and the other SCO countries on biodiversity conservation and the post-2020 global biodiversity framework goals,we gave some recommendations:(1)promoting access to genetic resources and benefit-sharing;(2)integrating multiple funds and innovating the implementation of funding mechanism;(3)developing talent training and exchange programs and deepening multilateral cooperation;(4)strengthening cross-border cooperation and improving cooperation network;and(5)establishing a coordination mechanism for biodiversity conservation within the framework of the SCO.

Biological Diversity, Land Degradation and Sustainable Rural Livelihoods

The 1998 Conference of Parties to the Convention on Biological Diversity asked national governments to demonstrate the importance of biological diversity in supporting rural communities. This paper introduces‘agrodiversity’as the primary way in which farmers use biological diversity and, more generally, the natural diversity of the environment for production, including their choice of crops, and management of land, water and biota as a whole. Promoting agrodiversity and understanding how it functions in tropical smallholder farming systems is the best way that importance may be shown. A win-win scenario is presented which links agrodiversity to land degradation control and sustainable rural livelihoods as evidenced by food security. It is argued that policies that encourage biological diversity in areas of land use will not only meet countries’ responsibilities under the Convention but will also address land degradation problems and support to rural livelihoods. The human significance of various types of biological diversity is shown. Sustainable rural livelihoods are presented in the new capital assets framework to demonstrate how rural households may use various components to control land degradation. To enable agrodiversity to be implemented practically, it has been codified into core elements of: biophysical diversity, the diversity of the natural environment that controls the resource base for food production; management diversity that embraces the practices (many of them indigenous) of farmers such as live hedges, soil amendments and ridge tillage techniques; agro-biodiversity which is the diversity of crop, plant and animal combinations; and organisational diversity, the way that farms are owned and operated, and the way that capital assets are allocated. Each element is then systematically related to show how agrodiversity controls land degradation and how it promotes food security. The example of the maize-Mucuna system in South America is cited as an evident demonstration of the value of agrodiversity to both soil conservation and to smallholder farmers’ livelihoods.

Plant biological diversity in natural secondary forests on Mao'er Mountains

The forest plant biological diversity investigations were conducted in Laoyeling Forest Ecological Experimental Station on Mao’er Mountains in eastern Heltongjiang Province. Sample plots were six different forest communities. Field works were divided into three seasons : spring, summer and autumn in one year. The results showed that forest plant biological diversity varied with seasons as well as growth forms. Herb species diversity values were the highest in the community growth forms. Diversity indices No, H’ and E1 were selected out as the best richness, diversity and evenness indices to indicate the biological diversity in forest community.

Taxonomy is the cornerstone of biodiversity conservation SEABRI reports on biological surveys in Southeast Asia

The Southeast Asia Biodiversity Research Institute （SEABRI） is an international scientific research and education organization affiliated directly to the Chinese Academy of Sciences （CAS） and managed by the Xishuangbanna Tropical Botanical Garden （XTBG）. By harnessing its connections with all CAS institutes, local institutes and international agencies and leveraging on their resources, it seeks to make a significant contribution to biodiversity conservation in Southeast Asia.

Forest plant biological diversity in Liangshui Nature Reserve

Investigations of forest plant biological diversity were conducted in Liangshui Nature Reserve, Xiaoxing’an Mountains in eastern Heilongjiang Province. Six samples were selected to initiate fieldwork in spring,summer and autumn. Two samples were added to the whole experiment. Results showed that plant biological diversity in the natural reserve varied with seasons as well as plant growth forms. Generalty the highest diversity values occurred in spring in the communities. Herb species had richer diversity than those of either shrub species or wood species. Species richness, diversity and evenness were quoted in the analysis.

Latitudinal gradients of biodiversity and ecosystem services in protected and non-protected oak forest areas can inform climate smart conservation

Adaptive governance of areas set aside for future protection of biodiversity,sustainable production,and recreation requires knowledge about whether and how effects of area protection are modulated by climate change and redistribution of species.To investigate this,we compare biodiversity of plants(assessed using vegetation plots)and arthropods(collected with Malaise traps,analyzed using metabarcoding)and productivity(tree growth,determined using dendrochronology)in protected and non-protected oak(Quercus spp.)forests along a latitudinal gradient(55.6°N–60.8°N)in Sweden.We also compare historical,recent and projected future climate in the region.In contrast to established global latitudinal diversity gradients,species richness of plants and arthropods increased northwards,possibly reflecting recent climate-induced community redistributions,but neither was higher in protected than in non-protected areas,nor associated with contemporary ground temperature.Species composition of arthropods also did not differ between protected and non-protected areas.Arthropod biomass increased with latitude,suggesting that the magnitude of cascading effects mediated via their roles as pollinators,herbivores,and prey for other trophic levels,varies geographically and will change with a moving climate.Annual growth rate of oaks(an ecosystem service in the form of biomass increase and carbon sequestration)was independent of latitude and did not differ between protected and non-protected areas.Our findings question the efficacy of contemporary designation and management of protected oak forests,and emphasize that development and implementation of modified climate smart conservation strategies is needed to safeguard ecosystem functioning,biodiversity,and recreational values of protected forest areas against future challenges.

Diversity and Biological Activities of Endophytic Fungi Associated with Micropropagated Medicinal Plant <i>Echinacea purpurea</i>(L.) Moench

Echinacea is one of the top ten selling medicinal herbs in Europe and United States. Commercially available formulations may contain different plant parts of three species (Echinacea purpurea, E. pallida, and E. angustifolia). Our study evaluates the diversity of microbial community associated with healthy E. purpurea clones and their ability to produce defense compounds. We recovered and identified thirty-nine fungal endophytes through the molecular methods in 15 distinct phylotypes, which were closely related to species of the following genera Ceratobasidium, Cladosporium Colletotrichum, Fusarium, Glomerella, and Mycoleptodiscus. These taxa were previously reported as decomposer and phytopathogenic fungi. The fungal community associated with two E. purpurea clones showed high richness and dominance indices with different distribution among plant organs. Crude extracts of fungal isolates were tested for antifungal and insecticidal biological activities. A total of 16 extracts (41%) showed antifungal properties;while just the extract of M. indicus exhibited larvicidal activity against A. aegypti. These results suggest that the symbiosis between the endophytic fungal community and micropropagated clones of E. purpurea was re-established after acclimatization to soil and the endophytic fungi produced compounds against phytopathogenic fungi.

Resilience effects for household food expenditure and dietary diversity in rural western China

A more resilient livelihood is increasingly recognized as an efficient way to improve vulnerable households’food security and optimize their dietary decisions.This study quantifies rural household resilience in western China,identifies the three pillars(absorptive capacity,adaptive capacity,and transformative capacity)contribution to resilience,and then establishes the estimated Resilience Capacity Index(RCI)linked with food security and dietary diversity supported by the multiple indicator multiple cause(MIMIC)model.Results show that,despite geographical heterogeneity,the RCI consistently increased from 2015 to 2021.Households with a higher RCI inheriting better capacity to deal with risk and shocks are significantly and positively correlated with increasing food expenditure and diversifying food choices.It can be because resilient households will allocate more money to food expenditure instead of saving for livelihood uncertainty.Thus,policymakers can provide more incentives for rural households to adopt more dynamic and effective risk management strategies.This,in turn,could yield positive spillover effects by preventing human capital loss associated with dietary-related chronic diseases and mortality.

The biological functions and metabolic pathways of valine in swine

Valine is an essential amino acid and a type of branched-chain amino acid. Due to the involvement of branchedchain amino acids in various metabolic pathways, there has been a surge of interests in valine nutrition and its role in animal physiology. In pigs, the interactions between valine and other branched-chain amino acids or aromatic amino acids are complex. In this review, we delve into the interaction mechanism, metabolic pathways, and biological functions of valine. Appropriate valine supplementation not only enhances growth and reproductive performances, but also modulates gut microbiota and immune functions. Based on past observations and interpretations, we provide recommended feed levels of valine for weaned piglets, growing pigs, gilts, lactating sows, barrows and entire males. The summarized valine nutrient requirements for pigs at different stages offer valuable insights for future research and practical applications in animal husbandry.

Biological Diversity VS. Urgent Protection

Not long ago, an international symposium was held in Lhasa to discuss ways and means of protecting and managing the region’s biological diversity. Wangdui took the advantage of the occasion to interview Mr. Li Bosheng, research fellow with the Beijing Plant Research Institute and Director of the Beijing Botanical Garden. Mr. Li is one of the few who discovered the U-turn canyon on the Yarlung Zangbo River. The following is his view on the symposium theme.

Off-farm employment,agriculture production activities,and household dietary diversity in environmentally and economically vulnerable areas of Asia

Access to off-farm employment has been expected to be a critical approach to ending hunger and all forms of malnutrition,two important targets of achieving Zero Hunger.This study aims to investigate the role of off-farm employment in improving dietary diversity through substitution effect and complementary effect with agricultural production activities and income effect.This study adopts Poisson/Tobit/Probit/OLS regressions and the instrument variable method based on the primary survey data collected among 1,282 households at 12 sites in environmentally and economically vulnerable areas of China,Nepal,Cambodia,Thailand,and Myanmar in 2019.The results show that off-farm employment is positively associated with household dietary diversity and the consumption of flesh meat,fish and other aquatic animals,fruits,and milk and dairy products,which are rich in protein and micronutrients.The results of mechanism analysis show that off-farm employment contributes to household dietary diversity by improving crop diversity,especially for poor households,boosting the probability of livestock raising for households with the middle one-third disposal income,and increasing household income.The positive association between off-farm employment and household dietary diversity is much higher for households with the bottom one-third disposal income,low illiteracy,and from upper-middle income countries.These findings imply that off-farm employment does play a vital role in achieving multiple benefits of poverty alleviation,malnutrition reduction,and agrobiodiversity conservation in environmentally and economically vulnerable areas.However,it may enlarge the gaps in dietary diversity between households with low human capital and from low and lower-middle income countries and those with high human capital and from middle-high countries.

Community structure and species diversity dynamics of a subtropical evergreen broad-leaved forest in China:2005 to 2020

Here,we characterize the temporal and spatial dynamics of forest community structure and species diversity in a subtropical evergreen broad-leaved forest in China.We found that community structure in this forest changed over a 15-year period.Specifically,renewal and death of common species was large,with the renewal of individuals mainly concentrated within a few populations,especially those of Aidia canthioides and Cryptocarya concinna.The numbers of individual deaths for common species were concentrated in the small and mid-diameter level.The spatial distribution of community species diversity fluctuated in each monitoring period,showing a more dispersed diversity after the 15-year study period,and the coefficient of variation on quadrats increased.In 2010,the death and renewal of the community and the spatial variation of species diversity were different compared to other survey years.Extreme weather may have affected species regeneration and community stability in our subtropical monsoon evergreen broad-leaved forests.Our findings suggest that strengthening the monitoring and management of the forest community will help better understand the long-and short-term causes of dynamic fluctuations of community structure and species diversity,and reveal the factors that drive changes in community structure.

Biodiversity metrics on ecological networks: Demonstrated with animal gastrointestinal microbiomes

Biodiversity has become a terminology familiar to virtually every citizen in modern societies.It is said that ecology studies the economy of nature,and economy studies the ecology of humans;then measuring biodiversity should be similar with measuring national wealth.Indeed,there have been many parallels between ecology and economics,actually beyond analogies.For example,arguably the second most widely used biodiversity metric,Simpson(1949)’s diversity index,is a function of familiar Gini-index in economics.One of the biggest challenges has been the high“diversity”of diversity indexes due to their excessive“speciation”-there are so many indexes,similar to each country’s sovereign currency-leaving confused diversity practitioners in dilemma.In 1973,Hill introduced the concept of“numbers equivalent”,which is based on Renyi entropy and originated in economics,but possibly due to his abstruse interpretation of the concept,his message was not widely received by ecologists until nearly four decades later.What Hill suggested was similar to link the US dollar to gold at the rate of$35 per ounce under the Bretton Woods system.The Hill numbers now are considered most appropriate biodiversity metrics system,unifying Shannon,Simpson and other diversity indexes.Here,we approach to another paradigmatic shift-measuring biodiversity on ecological networks-demonstrated with animal gastrointestinal microbiomes representing four major invertebrate classes and all six vertebrate classes.The network diversity can reveal the diversity of species interactions,which is a necessary step for understanding the spatial and temporal structures and dynamics of biodiversity across environmental gradients.

Na^(+)/K^(+)-ATPase:ion pump,signal transducer,or cytoprotective protein,and novel biological functions

Na^(+)/K^(+)-ATPase is a transmembrane protein that has important roles in the maintenance of electrochemical gradients across cell membranes by transporting three Na^(+)out of and two K^(+)into cells.Additionally,Na^(+)/K^(+)-ATPase participates in Ca^(2+)-signaling transduction and neurotransmitter release by coordinating the ion concentration gradient across the cell membrane.Na^(+)/K^(+)-ATPase works synergistically with multiple ion channels in the cell membrane to form a dynamic network of ion homeostatic regulation and affects cellular communication by regulating chemical signals and the ion balance among different types of cells.Therefo re,it is not surprising that Na^(+)/K^(+)-ATPase dysfunction has emerged as a risk factor for a variety of neurological diseases.However,published studies have so far only elucidated the important roles of Na^(+)/K^(+)-ATPase dysfunction in disease development,and we are lacking detailed mechanisms to clarify how Na^(+)/K^(+)-ATPase affects cell function.Our recent studies revealed that membrane loss of Na^(+)/K^(+)-ATPase is a key mechanism in many neurological disorders,particularly stroke and Parkinson's disease.Stabilization of plasma membrane Na^(+)/K^(+)-ATPase with an antibody is a novel strategy to treat these diseases.For this reason,Na^(+)/K^(+)-ATPase acts not only as a simple ion pump but also as a sensor/regulator or cytoprotective protein,participating in signal transduction such as neuronal autophagy and apoptosis,and glial cell migration.Thus,the present review attempts to summarize the novel biological functions of Na^(+)/K^(+)-ATPase and Na^(+)/K^(+)-ATPase-related pathogenesis.The potential for novel strategies to treat Na^(+)/K^(+)-ATPase-related brain diseases will also be discussed.

Effects of Photosynthetic Bacteria-enhanced Biological Floc Replacement Diets on Tilapia Growth,Water Environment and Water Microbial Diversity

With Oreochromis niloticus as the object of study,glucose was added as a carbon source to promote the formation of the biological flocs for replacing part of the feed,and three gradients were set up,namely Group A(all feed),Group B(replacement of 10%feed)and Group C(replacement of 20%feed),so as to explore the effects of photosynthetic bacteria-enhanced biological flocs on tilapia growth and water environment conditions.Meanwhile,the Biolog-ECO technology was applied to study the changes of microbial carbon metabolism diversity in aquaculture water.The results showed that the utilization of microbial carbon sources under different feed replacement gradients increased with the extension of the culture time.The overall performance was in order of 10%replacement>all feed>20%feed replacement.A suitable replacement rate could not only enhance the overall utilization of carbon sources by water microorganisms,but also save culture costs.The principal component analysis showed that the carbon source metabolism of the water microbial communities under different feed replacement gradients was significantly different.Specifically,polysaccharides,esters and amino acids were the preferred carbon sources of water microbes,while the utilization of amines and acids was low.

Herbivore and native plant diversity synergistically resist alien plant invasion regardless of nutrient conditions

Alien plant invasion success can be inhibited by two key biotic factors:native herbivores and plant diversity.However,few studies have experimentally tested whether these factors interact to synergistically resist invasion success,especially factoring in changing global environments(e.g.nutrient enrichment).Here we tested how the synergy between native herbivores and plant diversity affects alien plant invasion success in various nutrient conditions.For this purpose,we exposed alien plant species in potmesocosms to different levels of native plant diversity(4 vs.8 species),native generalist herbivores,and high and low soil nutrient levels.We found that generalist herbivores preferred alien plants to native plants,inhibiting invasion success in a native community.This inhibition was amplified by highly diverse native communities.Further,the amplified effect between herbivory and native plant diversity was independent of nutrient conditions.Our results suggest that a higher diversity of native communities can strengthen the resistance of native generalist herbivores to alien plant invasions by enhancing herbivory tolerance.The synergistic effect remains in force in nutrient-enriched habitats that are always invaded by alien plant species.Our results shed light on the effective control of plant invasions using multi-trophic means,even in the face of future global changes.