云南澜沧景迈古茶园生态系统植物多样性评价

云南澜沧县境内的景迈古茶园是云南省现存面积最大的古茶园.本文应用植物学样地调查和农业生物多样性调查评价(HH-ABA)方法,在景迈古茶园内设置了78个20 m×20 m的样方,对植物多样性进行调查,并就古茶园的管理及资源利用等问题进行了问卷调查和农户访谈.研究结果表明,景迈芒景地区植物地理成分的热带性明显.在景迈古茶园中发现的珍稀濒危保护植物达15种,其中濒危种5个,易危种7个,稀有种3个,含国家三级保护植物11种.从古茶园、天然林、新式茶园3类生态系统的物种多样性分析来看,古茶园与天然林较为接近而比新式茶园高得多,因而在该区生物多样性的维护上起着非常重要的作用.古茶园的物种数按照生活型排序为草本＞乔木＞灌木＞藤本＞附生.与天然林相比,古茶园内乔木和灌木种类的比例减少,草本和附生(寄生)植物的比例大大增加,这与古茶园内乔木郁闭度及茶树的存在密切相关.农业生物多样性分析显示,不同村寨的物种丰富度和物种利用率均存在差异.6个村寨的农业物种丰富度指数的平均值为0.059,高于同纬度地区旱谷地和橡胶林,可见人们在古茶园管理中有意识地保留了可利用的物种.由于不同农户采取的管理措施不同,影响了古茶园内的植物多样性和古茶树的更新,因而使各农户的茶叶经济效益存在差别.古茶园生态系统是自然资源保护与利用相结合的典型例子,建议应当传承并发展当地人民对古茶园的管理经验,由政府、科研机构和农户共同参与,通过示范和培训加强学习指导,对古茶园进行保护和合理的开发利用.     

Functional and phylogenetic diversity of an agricultural matrix avifauna: The role of habitat heterogeneity in Afrotropical farmland

Varied strategies to alleviate the loss of farmland biodiversity have been tested, yet there is still insufficient evidence supporting their effectiveness, especially when considering phylogenetic and functional diversity alongside traditional taxonomic diversity metrics. This conservation challenge is accentuated in the Afrotropics by the rapid agricultural expansion and intensification for the production of cash crops and by a comparative lack of research. In this study, we assessed how farming practices influence avian phylogenetic and functional diversity. We conducted point‐count surveys to assess avian diversity in monocultures of tea and mixed crop farming systems surrounding the Nyungwe rainforest in south‐west Rwanda, allowing us to investigate the drivers of avian diversity at farm level. Species composition was found to be moderately different between farm types, with mixed crop farms supporting higher phylogenetic diversity than tea plantations. There were no significant seasonal differences in species composition, functional or phylogenetic diversity. Overall, functional diversity did not differ between farm types, but the dispersion of trophic‐related traits was significantly higher in mixed crop farms. Both functional and phylogenetic diversity were influenced by floristic diversity, vegetation height, tree number, and elevation to varying degrees. Our results also (i) highlight the role of farmland heterogeneity (e.g., crop species composition, height, and tree cover extent) in encouraging avian functional and phylogenetic diversity in the Afrotropics and (ii) indicate that the generally negative biodiversity impacts of monoculture agriculture can be partially alleviated by extensive agroforestry with an emphasis on indigenous tree species.     

The genomic and bioclimatic characterization of Ethiopian barley (Hordeum vulgare L.) unveils challenges and opportunities to adapt to a changing climate

The climate crisis is impacting agroecosystems and threatening food security of millions of smallholder farmers. Understanding the potential for current and future climatic adaptation of local crop agrobiodiversity may guide breeding efforts and support resilience of agriculture. Here, we combine a genomic and climatic characterization of a large collection of traditional barley varieties from Ethiopia, a staple for local smallholder farmers cropping in challenging environments. We find that the genomic diversity of barley landraces can be partially traced back to geographic and environmental diversity of the landscape. We employ a machine learning approach to model Ethiopian barley adaptation to current climate and to identify areas where its existing diversity may not be well adapted in future climate scenarios. We use this information to identify optimal trajectories of assisted migration compensating to detrimental effects of climate change, finding that Ethiopian barley diversity bears opportunities for adaptation to the climate crisis. We then characterize phenology traits in the collection in two common garden experiments in Ethiopia, using genome-wide association approaches to identify genomic loci associated with timing of flowering and maturity of the spike. We combine this information with genotype–environment associations finding that loci involved in flowering time may also explain environmental adaptation. Our data show that integrated genomic, climatic, and phenotypic characterizations of agrobiodiversity may provide breeding with actionable information to improve local adaptation in smallholder farming systems.     

西双版纳社区旱稻品种多样性与就地保护初探

应用户级水平农业生物多样性评价方法,对云南省西双版纳州3个少数民族村寨(哈尼族大卡老寨、基诺族巴卡小寨和傣族曼那龙寨)的旱稻(Oryza sativa)品种进行收集,就旱稻品种的管理和利用等问题进行了问卷调查和农户访谈,并基于农艺性状的统计分析,初步探讨了社区旱稻品种多样性的就地保护措施。结果如下：(1)在3个调查村寨共记载收集到31个旱稻品种,多样的旱稻品种满足了人们的不同需求;(2)主成分分析结果表明,旱稻品种农艺性状多样性主要表现在产量性状和剑叶形态两个方面,其中巴卡小寨和大卡老寨的品种多样性均高于曼那龙寨,并且这些早稻品种中存在具优良性状的稻种资源;(3)3个少数民族村寨具有不同的民族文化背景,不同民族间或不同村寨农户间自发的种子交换以及他们传统的轮作、间作耕作方式,维持和提高了旱稻品种多样性;(4)通过保护民族文化和传统习俗,充分利用当地民族的旱稻种植管理知识,促进民间自发的种子交换,由政府、科研机构和农户共同参与,通过示范和培训加强科学指导,是对西双版纳社区旱稻品种资源多样性进行就地保护的有效措施。     

Comparative environmental and economic life cycle assessment of biogas production from perennial wild plant mixtures and maize (Zea mays L.) in southwest Germany

Maize silage is the main biogas co‐substrate in Germany, but its use is often questioned due to negative environmental impacts. Perennial wild plant mixtures (WPM) are increasingly considered alternatives, as these extensive systems improve soil quality and enhance agrobiodiversity. Methane yields per hectare however do not match those of maize. This study examined whether the potential advantages of replacing maize with WPM for biogas production are counteracted by lower yields and associated effects. Life cycle assessment and life cycle cost assessment were used to compare the environmental and economic performance of electricity generation from WPM in two establishment procedures, ‘standard’ (WPM E1) and ‘under maize’ (WPM E2). These metrics were benchmarked against those of maize. The production of 1 kWh electricity was chosen as functional unit. The life cycle inventory of the agricultural phase was based on multi‐annual field trials in southwest Germany. Both WPM E1 and E2 had lower marine eutrophication and global warming potentials than maize. The GWP favourability was however sensitive to the assumptions made with regard to the amount and fate of carbon sequestered in the soil. WPM E1 performed less favourable than WPM E2. This was mainly due to lower yields, which could, in turn, result in potential indirect land use impacts. These impacts may outweigh the carbon sequestration benefits of WPM cultivation. Maize performed best in terms of economic costs, freshwater eutrophication, terrestrial acidification, fine particulate matter and ozone formation. We conclude that the widespread deployment of WPM systems on productive agricultural land should only take place if permanent soil carbon sequestration can be ensured. In either case, WPM cultivation could be a valid alternative for bioenergy buffers and marginal land where competitive yields of common crops cannot be guaranteed, but which could accommodate low‐input cultivation systems.     

Isolation and characterization of trinucleotide repeat microsatellite markers for Plutella xylostella L.

Thirteen microsatellite markers generating high quality patterns have been developed and characterized for diamondback moth (Plutella xylostella L.), of which 11 are based on trinucleotide repeats. These markers are polymorphic, generating up to 15 alleles in a test set of 12 caterpillars. The markers will be useful to assess the differentiation of P. xylostella populations and the exchange of pest populations between sites with crops, green manure crops and weeds.     

Biological Diversity, Dietary Diversity, and Eye Health in Developing Country Populations: Establishing the Evidence-base

Human and ecosystem health converge around biological diversity issues. Cultivated and wild plants as food and medicine make essential contributions to human health, which in turn provides rationales for conservation. While wild and cultivated plant diversity reasonably facilitates dietary diversity and positive health outcomes, the challenges of demonstrating this relationship limit its impact in concept, policy, and practice. We present a rationale for testing the dietary contribution of biological diversity to improved eye health as a case study based on existing phytochemical, pharmacological, and clinical knowledge. We consider the empirical evidence needed to substantiate, interpret, and apply this relationship at a population and ecosystem level within a unified research framework. Epidemiological data strongly support the prevention of childhood vitamin A deficiency blindness, cataract, and age-related macular degeneration by fruit and vegetable consumption. Phytonutrients, including the carotenoids lutein and zeaxanthin, protect the eye from oxidative stress and harmful light exposure. Laboratory, community, and population level research should prioritize food composition of dietary plants from both agriculture and the wild. Intervention studies, focus groups, and transmission of knowledge of local species and varieties within communities will further interpretation of epidemiological data. Population-based studies combining clinical data and measures of access and consumption of biological diversity are key to demonstrating the important relationships among biodiversity, dietary diversity, and health outcomes.     

The conservation of agrobiodiversity on-farm: questioning the emerging paradigm

The genetic diversity of traditional varieties of crops is the most economically valuable part of global biodiversity and is of paramount importance for future world crop production. The Biodiversity Convention has given a clear mandate for on-farm conservation. However, very little formal research has been done and no agreed set of scientific principles yet exists for on-farm conservation of genetic resources. This lack of scientific knowledge has not prevented an explosion of recommendations on how to conserve agrobiodiversity on-farm and it is possible to identify an emerging paradigm. Through a review of some of the assumptions on which this paradigm is based, we clearly show that if attempts to conserve agrobiodiversity on-farm are based on these misconceptions, they are likely to fail. By assessing the present activities of farmers, we propose a research agenda to increase the diversity available to farmers and to enhance farmers' capacity to manage this diversity dynamically. Increasing genetic diversification, combined with farmers' experimental abilities, and underpinned by the formal system, will ensure greater on-farm conservation of more useful genetic resources.