利用农业生物多样性持续控制有害生物

农业生物多样性对保障全球粮食安全和农业可持续发展至关重要.人类在多样性的形成上发挥了关键作用,人类结合自然进化创造了遗传多样性、物种多样性和生态系统多样性.农业生物多样性发挥了很多社会经济和环境功能:保障粮食安全;维持农业生态系统可持续发展;赋予农村经济适变性.但当前人类毁灭农业生物多样性的速度更为惊人.在总结石油农业单一化种植的生态负效应、传统农业提倡“天人合一”的生态正效应的基础上,分析讨论了利用农业生物多样性持续控制有害生物的必要性和可行性,从生态系统多样性、物种多样性和种内遗传多样性3个层次,归纳了构建和恢复农田生物多样性的基本方法.基于病理学、生态学、营养学和生理学等学科领域,从群体异质效应、稀释效应、微生态效应、诱导抗性效应、物理阻隔效应、生理学效应和化感效应等7个方面,归纳了利用农业生物多样性持续控制有害生物的基础原理.寻求低投入、高效益、多样化和可持续的农业生产系统是当今世界许多科学家、决策者和生产者共同关心的问题.农业生物多样性具有重要的生态作用,在现代农业框架下,是合情合理构建持续、稳定、健康、高产的农田生态系统,持续控制有害生物的金钥匙.为此必须加强四方面的课题研究:各种作物之间的相生相克关系及其作用机理;各种有害生物的主要天敌种类、生物学、生态学特性及其适生环境;利用农业生物多样性全面、持续控制有害生物的农业生产模式;与其相配套的农艺措施与农业机械.     

Plants in traditional home gardens: richness,composition, conservation and implications for native biodiversity in Benin

Home gardens have received increasing attention and have been insistently presented as hotspots for agro-biodiversity over the last decades. However, apart from their exceptional high plant species diversity, there is little quantitative evidence of the effectiveness of plant species conservation in home gardens. This study examined this issue by assessing (i) the size and membership of garden flora and the contribution to the maintenance of the national flora, (ii) how home garden flora connects to the larger ecosystem it belongs to and (iii) the conservation status of plant species at the home garden level. 360 home gardens distributed in three agro-ecological zones and nine phyto-geographical districts in Benin were visited and inventoried. Diversity parameters at different taxonomic levels were calculated. Species accumulation and spatial occupancy, multivariate methods and rarity index were also used for data analysis. Findings showed that the 360 studied home gardens hosted up to 14.21% of plant species and 44.32% of plant families of the national flora. Home garden flora was constantly dominated by exotic plant species but strongly connected to their surrounding ecosystems, being composed of at least 60% of plant species from their phyto-geographical districts. Finally, home garden plant species were mostly rare and threatened at the home garden level. In this study, we acknowledge the contribution of home gardens to the maintenance of plant species diversity at regional and global levels than local level. Based on the observed prevalence of exotic species, HG effectiveness in sustainably conserving native plant species biodiversity remains questionable.     

Using home gardens to decipher health and healing in the Andes

Home gardens are a pervasive component of Andean agricultural systems, but have been ignored in anthropological and agronomic research. Recent research in the indigenous community of Saraguro, Ecuador, employed a combination of in-depth interviews, free-listing, videotaped walk-throughs, and mapping to explore the role of home gardens, which are established and controlled by women. Findings reveal that, although gardens offer multiple benefits, they are overwhelmingly devoted to the cultivation of medicinal plants, operating as de facto medicine cabinets that supply women with most of the resources they need to treat family illnesses. Results also suggest that the natural history of home gardens mirrors transformations within the family, and that Saraguro women study the contents of their neighbors' gardens, using this knowledge as a foundation for deciphering the owners' economic and health status. New threats to the sustainability of home gardens threaten the foundation of Saraguro's ethnomedical system and women's authority in the home and community.     

Functional diversity of home gardens and their agrobiodiversity conservation benefits in Benin,West Africa

Background

Understanding the functional diversity of home gardens and their socio-ecological determinants is essential for mainstreaming these agroforestry practices into agrobiodiversity conservation strategies. This paper analyzed functional diversity of home gardens, identified the socio-ecological drivers of functions assigned to them, and assessed the agrobiodiversity benefits of home gardens functions.

Methods

Using data on occurring species in home garden (HG) and functions assigned to each species by the gardeners, the study combined clustering and discriminant canonical analyses to explore the functional diversity of 360 home gardens in Benin, West Africa. Next, multinomial logistic models and chi-square tests were used to analyze the effect of socio-demographic characteristics of gardeners (age, gender, and education level), agro-ecological zones (humid, sub-humid, and semi-arid), and management regime (single and multiple managers) on the possession of a functional type of home gardens. Generalized linear models were used to assess the effect of the functions of home gardens and the determinant factor on their potential in conserving agrobiodiversity.

Results

Seven functional groups of home gardens, four with specific functions (food, medicinal, or both food and medicinal) and three with multiple functions (more than two main functions), were found. Women owned most of home gardens with primarily food plant production purpose while men owned most of home gardens with primarily medicinal plant production purposes. Finding also showed that multifunctional home gardens had higher plant species diversity. Specifically, crops and crop wild relatives occurred mainly in home gardens with food function while wild plant species were mostly found in home gardens with mainly medicinal function.

Conclusions

Home gardening is driven by functions beyond food production. These functions are mostly related to direct and extractive values of home gardens. Functions of home gardens were gendered, with women mostly involved in home food gardens, and contribute to maintenance of crops and crop wild relatives while men were mostly home medicinal gardeners and contribute to the maintenance of wild plant species in home gardens. Although multiple functional home gardens were related to higher plant diversity, there was no guarantee for long-term maintenance of plant species in home gardens.

     

Culturally valuable minority crops provide a succession of floral resources for flower visitors in traditional orchard gardens

Agricultural intensification typically has detrimental effects on pollinator communities, but diverse cropping systems that contain sequentially-flowering crops have the potential to benefit pollinators through the provision of additional floral resources. In this study we investigate the importance of cultivated flora for flower visitors in ten agricultural gardens in South Sinai, Egypt. Insect-flower interactions in gardens and unmanaged plots were surveyed across a four-month period in two environmentally distinct years (pre-flood and post-flood). Despite containing an equal abundance and diversity of wild plants as unmanaged habitat, gardens supported a higher abundance and diversity of flower visitors due to the additional presence of cultivated flora. Visitation networks exhibited dramatic intra-annual changes in composition, with cultivated plants becoming increasingly important in later months. Trends were highly conserved across 2 years despite highly contrasting rainfall. Several key crop species were strongly involved in shaping the structure of the networks, the majority of which were herbs with strong cultural significance (fennel, rosemary, mint) and grown incidentally alongside the primary orchard crops. Minority crops are frequently overlooked in agricultural systems due to their low economic value, but we show that they can have a dramatic influence upon the structure of visitation networks, increasing both pollinator abundance and diversity, and emphasising the link between cultural practices and biodiversity conservation.     

Reconfiguring Agrobiodiversity in the Amazon Estuary: Market Integration, the Açaí Trade and Smallholders’ Management Practices in Amapá, Brazil

An established body of literature documents current changes in rural livelihoods, agricultural practices, and agrobiodiversity patterns in smallholder communities across the globe. Contributing to this literature, this paper documents change in agricultural practices and agrobiodiversity patterns in a tidal floodplain settlement in Amapá, Brazil, where in recent years farmers increasingly devote their attention to the production of açaí fruits, an important regional crop with strong local, national and international markets. Research results indicate that farmers are abandoning subsistence production in annual fields to make room for açaí-dominated agroforests. At the same time, farmers are diversifying home gardens, and as a result conserve a portion of the crop diversity once maintained in annual fields in these areas. Agrobiodiversity documented in home gardens is much higher than previously recorded in the study area, and is equal or higher than previously reported in home gardens in other less-market integrated Amazonian communities. Research points to the need for innovative methods to document agrobiodiversity patterns in today’s modifying landscapes and for the historical analysis of such patterns to avoid presumptions that observed changes are unilateral and unidirectional.     

Traditional agricultural gardens conserve wild plants and functional richness in arid South Sinai

Maintaining agricultural diversity is important for the conservation of rare species and for preserving underlying ecosystem processes on which smallholder farmers rely. The positive effects of crop diversity are well documented in tropical systems, but the conservation potential of arid agricultural systems is less clear. This study assesses the impact of three arid agroforestry systems on plant diversity and functional richness in South Sinai, Egypt: (1) mountain orchard gardens, (2) modern town gardens and (3) low desert date-palm gardens. We surveyed plants (cultivated and wild) within gardens and control plots of natural habitat and allocated each plant eight biological traits that are recognised as being linked with major ecosystem processes. Species diversity was quantified using three measures (Hill's numbers) and total species diversity was significantly higher within gardens than in the surrounding habitat at all three levels of diversity and across the three agroforestry systems. Species similarity was high between gardens and the surrounding habitat, and there was a strong overlap in the functional traits of wild plants and cultivated non-tree species. Despite the clear presence of trees within the gardens, the community weighted trait means (CWMs) showed that chamaephyte perennials were the dominant life-forms in both the gardens and the natural habitat. Functional richness differed between the three agroforestry systems, but was significantly higher within the gardens. Functional richness has been linked to increased productivity and CWMs showed that plants within the gardens were considerably taller than outside, suggesting higher biomass accumulation. These findings suggest that Bedouin agricultural practices are not having a negative effect on the flora of the region and that the continuation of these indigenous farming practices can actively benefit rare wild plants in the region. On a wider scale, this study supports the view that smallholder farms and homegardens can be valuable tools in conservation, preserving local species and maintaining ecosystem functioning.     

Home Gardens Sustain Crop Diversity and Improve Farm Resilience in Candelaria Loxicha,Oaxaca, Mexico

Home gardens are land use units embedded in a larger land use system, in this case in Candelaria Loxicha, Oaxaca, Mexico. Using a combination of qualitative and quantitative methods, we investigated how home gardens are integrated into local farming practices and how these influence biodiversity. Our findings suggest that home gardens harbour high levels of biodiversity, which are maintained and enriched by farmers’ practices, particularly plant and seed exchange. Plant diversity is higher in younger home gardens and in home gardens where owners actively exchange plant material with other people. Through plant exchange, seed storage, and the dispersion of seeds and plants in different land uses, farmers encourage plant diversity and consequently increase the resilience of their farming system in changing climatic, demographic and economic conditions. Both men and women participate in the establishment, care and management of home gardens, but they are responsible for different plants and home garden functions. For economic reasons, the inhabitants of Candelaria Loxicha are increasingly engaging in international migration. Migrants, upon their return bring new ideas and plants that might transform the rural landscape.     

农业生物多样性保护履约进展及对我国农业发展的启示

农业生物多样性是《生物多样性公约》(以下简称《公约》)履约的核心议题之一, 对世界粮食安全、农业可持续发展以及实现碳中和具有重要实践意义。然而, 越来越多的研究表明, 由于人口的持续增长和饮食结构的根本性改变, 农业扩张已成为生物多样性丧失的主要驱动力之一。本文基于《公约》条款、第二次至第十四次缔约方大会相关决定、生物多样性和生态系统服务政府间科学与政策平台评估报告、第五版《全球生物多样性展望》(GBO-5)等内容, 系统梳理了《公约》谈判中农业生物多样性的履约进展和演变进程, 分析了农业生物多样性面临的严峻形势及存在问题。在此基础上, 从深入农业生物多样性相关指标研究、基于自然的解决方案、实现农业绿色可持续发展以及推动非国家利益相关方参与等层面, 就加强中国农业生物多样性保护工作提出建议, 以期有利于塑造中国良好对外形象, 也为维护世界农业稳定和粮食安全、推动《公约》第十五次缔约方大会(COP15)的顺利召开和成果达成奠定科学基础。     

Edible begonias from the North of Puebla, Mexico

The Sierra Norte de Puebla, Mexico, is a region with biological and cultural diversity, where the use of local natural resources was increased by the relative isolation of the region until recent decades. There are more than 600 useful plants reported. In the Sierra Norte de Puebla at least six Begonia species are used as food. The objective of this paper is to report such species that are utilized for self-supply and for sale in local markets. The management includes gathering among wild populations, transplanting of rhizomes and vegetative propagation by leaves to establish and increase populations in home gardens and in coffee plantations.     

Cultivated plant species diversity in home gardens of an Amazonian peasant village in Northeastern Peru

Research on agrobiodiversity points to the importance of home gardens in situ conservation, yet few studies to date explicate the origins and dynamics of plant species diversity. In this paper, we examine inter-household variations in cultivated plant species diversity among house gardens in a traditional peasant community, near Iquitos, Peru. In-depth household interviews (n = 24) and garden/field surveys reveal that home gardens are clearly the site of highest plant diversity in farmers’ field portfolios, and that substantial differences exist in garden composition, plant diversity, and the sources of garden planting material across households. Statistical analyses indicate that home garden diversity is related strongly to specific garden characteristics, household socioeconomic features, and access to planting material including seeds, cuttings, and suckers. The role and implications of differential access to planting material in the development and maintenance of crop species diversity is signaled as an important theme for future study in economic botany.     

中国古代在认识和保护生物多样性方面的贡献

中国古代的先人们经过长期劳动实践和调查研究,很早就对生物物种、生态环境及遗传的多样性有了较多认识,并记述在浩如烟海的典籍中。他们还通过发展农牧业、合理利用和管理生物资源以及建立各种形式的保护地和园林等,为保护生物多样性作出了巨大贡献。     

Home gardens in western Nepal: opportunities and challenges for on-farm management of agrobiodiversity

Home gardens are defined as a system of production of diverse crop plant species, which can be adjacent to household or slightly further away and is easily accessible. Species composition and management systems of Nepalese home gardens are poorly known. The study was conducted to develop an inventory on composition of crop species and varietal diversity to characterise the home gardens of Rupandehi and Gulmi of western Nepal, and to observe the species change over the time for last 10–15 years. Semi-structured Interviews, Direct Observation and Focus Group Discussions were employed to collect primary data. Shannon–Weaver index (SWI) was used to determine the species richness. Principal Component Analysis (PCA) was employed to characterise the home gardens. Mid-hill SWI (H′ = 4.41) revealed the higher species diversity (131 species) as compared to terai (123 species). This species richness was significantly higher (p = 0.001) in the mid-hill area. The vegetable species constitute the major component followed by fruits and fodder species that also contributed to the species diversity. The size of home gardens and species richness was positively correlated (r _s = 0.29, p = 0.001). Twenty crop species have been lost during the last 10–15 years and eleven species were threatened in the studied home gardens. Inaccessibility of local seed crops and deforestation were the major causes reported accounting for this trend. Self-saved seed was the major source of planting material in home gardens. There is a need to study the seed supply system for these home gardens. Therefore, a challenge is to make these home gardens self-supporting through creating a mechanism on strengthening local seed supply systems for long term sustainability of home garden in agrobiodiversity management.     

Managing diversity: Domestication and gene flow in Stenocereus stellatus Riccob. (Cactaceae) in Mexico

Microsatellite markers (N = 5) were developed for analysis of genetic variation in 15 populations of the columnar cactus Stenocereus stellatus, managed under traditional agriculture practices in central Mexico. Microsatellite diversity was analyzed within and among populations, between geographic regions, and among population management types to provide detailed insight into historical gene flow rates and population dynamics associated with domestication. Our results corroborate a greater diversity in populations managed by farmers compared with wild ones (H_E = 0.64 vs. 0.55), but with regional variation between populations among regions. Although farmers propagated S. stellatus vegetatively in home gardens to diversify their stock, asexual recruitment also occurred naturally in populations where more marginal conditions have limited sexual recruitment, resulting in lower genetic diversity. Therefore, a clear‐cut relationship between the occurrence of asexual recruitment and genetic diversity was not evident. Two managed populations adjacent to towns were identified as major sources of gene movement in each sampled region, with significant migration to distant as well as nearby populations. Coupled with the absence of significant bottlenecks, this suggests a mechanism for promoting genetic diversity in managed populations through long distance gene exchange. Cultivation of S. stellatus in close proximity to wild populations has led to complex patterns of genetic variation across the landscape that reflects the interaction of natural and cultural processes. As molecular markers become available for nontraditional crops and novel analysis techniques allow us to detect and evaluate patterns of genetic diversity, genetic studies provide valuable insights into managing crop genetic resources into the future against a backdrop of global change. Traditional agriculture systems play an important role in maintaining genetic diversity for plant species.     

Cocoa farms in the Mount Cameroon region: biological and cultural diversity in local livelihoods

A study was undertaken around Mt Cameroon to examine the role of biological and cultural diversity in the livelihood strategies of indigenous villagers and migrants to the region. Surveys of resources consumed and sold by 118 households were undertaken in five villages over the course of 1 year, the perspectives and practices of cocoa farmers documented, and useful tree species retained or planted on six cocoa farms mapped. Cocoa farms in this region generate more significant benefits for biodiversity conservation and local livelihoods than commercial plantations, but also place pressure on forest reserves and require chemical inputs. Roughly 50 tree species are commonly retained or planted on cocoa farms, primarily for timber or food, with many of these having high conservation value. Average tree density of non-cocoa trees was 15 trees per hectare, with tree densities higher, and a larger percentage of species used, on indigenous Bomboko farms than migrant farms. Both migrant and indigenous households rely on forest as a complement to farm income, but indigenous households do this to a far greater extent, while also making extensive use of fallow and home gardens. Indigenous households also derive roughly four times the income from wild and native species compared to migrants. While diversified cocoa farms contribute to conservation and livelihoods in the region, indigenous livelihoods grow from and require the conservation of a broader range of species and habitats, including natural forest.     

注意植物迁地保护中的遗传风险

稀有濒危植物迁地保护的长期目标之一就是要保护物种的遗传多样性和进化潜力。介绍了稀有濒危植物在植物园迁地保护过程中存在的一系列遗传风险。由于引种或取样的不足,容易导致被保存的物种缺乏足够的遗传代表性;盲目的引种、不合理的定植以及材料的来源不清则会导致稀有濒危植物的遗传混杂、近交衰退或杂交衰退;人为选择和生长环境的改变也容易造成濒危物种对迁地保护的遗传适应。在实际的迁地保护工作中,这些遗传风险往往被忽视。植物迁地保护中遗传风险将严重影响稀有濒危物种的回归和恢复。植物园应当重视濒危植物的遗传管理,以降低或避免迁地保护中的遗传风险。Abstract: Conserving genetic diversity of rare and endangered species and their evolutionary potential is one of the long-term goals of ex-situ conservation. Some potential genetic risks in ex-situ conservation in botanical gardens are presented. The preserved species may lack genetic representativity because of poor sampling. Inappropriate plantations, inadequate records and unclear kinships jeopardize endangered species to genetic confusion, inbreeding depression or outbreeding depression. Artificial selection and habitat conversion also potentially result endangered plants in adapting to ex-situ conservation, which had been usually overlooked. All the genetic risks can decrease the success of reintroduction and recovery. Therefore, appropriate genetic management should be carried out in botanical gardens to decrease or avoid genetic risks in ex-situ conservation.     

Landraces <Emphasis Type="Italic">in situ</Emphasis> Conservation: A Case Study in High-Mountain Home Gardens in Vall Fosca,Catalan Pyrenees,Iberian Peninsula<Superscript>1</Superscript>

Landraces in situ Conservation: A Case Study in High-Mountain Home Gardens in Vall Fosca, Catalan Pyrenees, Iberian Peninsula. Interest in landrace conservation has grown over the last few decades with much research focusing on the maintenance of on-farm crop genetic diversity in the tropics. Research on landraces is less abundant in temperate climates. In this paper we assess landrace conservation status in home gardens in Vall Fosca (Catalan Pyrenees, Iberian Peninsula). We estimate the individual socio-demographic attributes associated with in situ conservation of landraces and explore the reasons for their conservation. Fieldwork was conducted March–September 2008, during which time we surveyed 60 home gardens, owned by 53 tenders from 16 villages. We recorded occurrence, abundance, uses, and management of plants cultivated in home gardens. We also inquired about the informants’ reasons for conserving landraces. We found 148 different species. We identified 39 landraces corresponding to 31 species. Women, people over 65 years of age, experienced gardeners, and people who grow their home garden organically were more likely to conserve landraces than people without those characteristics. Although the informants express a strong preference for landraces, they mainly grow commercial varieties. Landraces seem to be displaced by less labor-intensive commercial varieties.     

The house gardens of Santa Rosa: Diversity and variability in an Amazonian agricultural system

Most research on house gardens suggests that this agricultural production type reaches its greatest development in areas of high population density. Gardens in low density areas such as the Amazon Basin have, to date, attracted little attention. A sample of house gardens in a ribereno village of the Peruvian Amazon is described and their great species diversity and variability in size and composition are discussed. The processes by which gardens in the village evolve and change are outlined. The study indicates that many young people of the village have a continuing interest in maintaining complex house gardens. More research on Amazonian house gardens is urged.