A global approach to crop wild relative conservation: securing the gene pool for food and agriculture

In light of the growing concern over the potentially devastating impacts on biodiversity and food security of climate change and the massively growing world population, taking action to conserve crop wild relatives (CWR), is no longer an option — it is a priority. Crop wild relatives are species closely related to crops, including their progenitors, many of which have the potential to contribute beneficial traits to crops, such as pest or disease resistance, yield improvement or stability. They are a critical component of plant genetic resources for food and agriculture (PGRFA), have already made major contributions to crop production and are vital for future food security; their systematic conservation in ways that ensure their continuing availability for use is therefore imperative. This is a complex, interdisciplinary, global issue that has been addressed by various national and international initiatives. Drawing on the lessons learnt from these initiatives we can now propose a global approach to CWR conservation, the key elements of which are: (1) estimating global CWR numbers, (2) assessment of the global importance of CWR diversity, (3) current conservation status, (4) threats to CWR diversity, (5) systematic approaches to CWR conservation, (6) CWR informatics, and (7) enhancing the use of CWR diversity.     

New approaches for establishing conservation priorities for socio-economically important plant species

The establishment of priorities among species is a crucial step in any conservation strategy since financial resources are generally limited. Traditionally, priorities for conservation of plant species have been focused on endemicity, rarity and particularly on their threatened status. Crop wild relatives (CWR) and wild harvested plants (WHP) are important elements of biodiversity with actual or potential socio-economic value. In this study, eight prioritisation criteria were used along with different prioritisation systems and applied to the Portuguese CWR and WHP. The top 50 species obtained by each of these methods were identified. The final top CWR were those that occurred as a priority in most methods. Twenty CWR were identified as the highest priorities for conservation in Portugal and they include wild relatives of the crop genera Allium, Daucus, Dianthus, Epilobium, Festuca, Herniaria, Narcissus, Quercus, Plantago, Trifolium, and Vicia. Eighteen WHP were recognised as priorities for conservation and include several Narcissus and Thymus species, among others. The advantages, limitations and level of subjectivity of each of the methods used in this exercise are discussed.     

Gap analyses of priority wild relatives of food crop in current ex situ and in situ conservation in Indonesia

Conservation programmes are always limited by available resources. Careful planning is therefore required to increase the efficiency of conservation and gap analysis can be used for this purpose. This method was used to assess the representativeness of current ex situ and in situ conservation actions of 234 priority crop wild relatives (CWR) in Indonesia. This analysis also included species distribution modelling, the creation of an ecogeographical land characterization map, and a complementarity analysis to identify priorities area for in situ conservation and for further collecting of ex situ conservation programmes. The results show that both current ex situ and in situ conservation actions are insufficient. Sixty-six percent of priority CWRs have no recorded ex situ collections. Eighty CWRs with ex situ collections are still under-represented in the national genebanks and 65 CWRs have no presence records within the existing protected area network although 60 are predicted to exist in several protected areas according to their potential distribution models. The complementarity analysis shows that a minimum of 61 complementary grid areas (complementary based on grid cells) are required to conserve all priority taxa and 40 complementary protected areas (complementary based on existing protected areas) are required to conserve those with known populations within the existing in situ protected area network. The top ten of complementary protected areas are proposed as the initial areas for the development of CWR genetic reserves network in Indonesia. It is recommended to enhanced coordination between ex situ and in situ conservation stakeholders for sustaining the long term conservation of CWR in Indonesia. Implementation of the research recommendations will provide for the first time an effective conservation planning of Indonesia’s CWR diversity and will significantly enhance the country’s food and nutritional security.

     

Comparative phylogeography and the identification of genetically divergent areas for conservation

Genetic diversity is recognized as a fundamental component of biodiversity and its protection is incorporated in several conventions and policies. However, neither the concepts nor the methods for assessing conservation value of the spatial distribution of genetic diversity have been resolved. Comparative phylogeography can identify suites of species that have a common history of vicariance. In this study we explore the strengths and limitations of Faith's measure of 'Phylogenetic Diversity' (PD) as a method for predicting from multiple intraspecific phylogeographies the underlying feature diversity represented by combinations of areas. An advantage of the PD approach is that information on the spatial distribution of genetic diversity can be combined across species and expressed in a form that allows direct comparison with patterns of species distributions. It also seeks to estimate the same parameter, feature diversity, regardless of the level of biological organization. We extend the PD approach by using Venn diagrams to identify the components of PD, including those unique to or shared among areas and those which represent homoplasy on an area tree or which are shared across all areas. PD estimation should be complemented by analysis of these components and inspection of the contributing phylogeographies. We illustrate the application of the approach using mtDNA phylogeographies from vertebrates resident in the wet tropical rainforests of north-east Queensland and compare the results to biodiversity assessments based on the distribution of endemic vertebrate species. The genetic vs. species approaches produce different assessments of conservation value, perhaps reflecting differences in the temporal and spatial scale of the determining processes. The two approaches should be seen as complementary and, in this case, conservation planning should incorporate information on both dimensions of biodiversity.     

Endemic wild potato (Solanum spp.) biodiversity status in Bolivia: Reasons for conservation concerns

Crop wild relatives possess important traits, therefore ex situ and in situ conservation efforts are essential to maintain sufficient options for crop improvement. Bolivia is a centre of wild relative diversity for several crops, among them potato, which is an important staple worldwide and the principal food crop in this country. Despite their relevance for plant breeding, limited knowledge exists about their in situ conservation status. We used Geographic Information Systems (GIS) and distribution modelling with the software Maxent to better understand geographic patterns of endemic wild potato diversity in Bolivia. In combination with threat layers, we assessed the conservation status of all endemic species, 21 in total. We prioritised areas for in situ conservation by using complementary reserve selection and excluded 25% of the most-threatened collection sites because costs to implement conservation measures at those locations may be too high compared to other areas. Some 70% (15 of 21 species) has a preliminary vulnerable status or worse according to IUCN red list distribution criteria. Our results show that four of these species would require special conservation attention because they were only observed in <15 locations and are highly threatened by human accessibility, fires and livestock pressure. Although highest species richness occurs in south-central Bolivia, in the departments Santa Cruz and Chuquisaca, the first priority area for in situ conservation according to our reserve selection exercise is central Bolivia, Cochabamba; this area is less threatened than the potato wild relatives’ hotspot in south-central Bolivia. Only seven of the 21 species were observed in protected areas. To improve coverage of potato wild relatives’ distribution by protected areas, we recommend starting inventories in parks and reserves with high modelled diversity. Finally, to improve ex situ conservation, we targeted areas for germplasm collection of species with <5 accessions conserved in genebanks.     

Evolutionary history of <Emphasis Type="Italic">campo rupestre</Emphasis>: an approach for conservation of woody plant communities

The campo rupestre sensu lato is among the most species-rich vegetation in the world, harbouring a high proportion of endemic species. We aimed to identify the processes that could generate a high level of phylogenetic diversity (PD) in campo rupestre for woody species and point out biodiversity hotspot areas which may provide additional information for conservation planning. We compiled a database of 2049 woody species from 185 community inventories. We calculated the evolutionary history using species richness (SR), PD, mean pairwise phylogenetic distance between species (MPD), the mean nearest taxon distance (MNTD) and their equivalents standardised (ses.PDss, ses.MPD, ses.MNTD), evolutionary distinctiveness (ED), and biogeographically weighted evolutionary distinctiveness (BED). Cloud dwarf-forests had the highest SR, PD, MPD and ses.MPD and lowest MNTD, while rupestrian cerrado presented the highest ses.PD and ses.MNTD. All areas are important for conservation, but the intersections between the hotspots should receive special attention in future conservation actions. The grids identified as hotspots by three or more metrics were localized mainly in Espinhaço Range in Minas Gerais State and a further expansion of protected areas is required. Moreover, the intersections between the hotspots obtained by mean ED and ses.PD are concentrated in the rocky dwarf forest and rupestrian cerrado, with considerable conservation gaps. The degree of protection of campo rupestre was low with unprotected areas comprising 56% of the species. Our results show an urgent need for increasing protected areas of campo rupestre in order to avoid the loss of valuable, endemic species with unique evolutionary history.     

Should evolutionary history guide conservation?

Phylogenetic diversity (PD) is an emerging tool for prioritising species in biodiversity conservation problems. PD uses the evolutionary history of a group of species to provide a formal measure of their biodiversity. This provides an objective target for biodiversity conservation, in which decisions are frequently made for political reasons or according to the charisma of a species. Incorporating PD in biodiversity decisions ensures that the best outcome given current knowledge is achieved. Unfortunately, the phylogenetic information required to calculate PD is frequently unknown or costly to obtain. Using PD in a decision making framework also complicates the process substantially, thereby decreasing its transparency and potentially disillusioning stakeholders. Here we provide a broad assessment of the value of PD in biodiversity conservation approaches. We find that using PD in a prioritisation process can typically increase biodiversity outcomes by a broad range of 10–220 %. Higher gains are obtained where (i) few species are selected, (ii) the phylogeny includes speciation events on a broad range of time scales and/or (iii) closely related species are prioritised in the absence of PD (e.g. several closely related charismatic animals). Our results indicate situations where PD is likely to contribute substantially to biodiversity conservation decisions and provides guidance to organisations when deciding whether to incorporating phylogenetic information in their decision making. This assessment is crucial as inclusion of PD may be costly and reduces transparency of the decision process, however the potential gains may far outweigh this cost.     

转基因植物对农业生物多样性的影响

论述了近年来转基因植物对农业生态系统生物多样性影响的研究进展．主要在遗传多样性、物种多样性和生态系统多样性3个层次上予以评述．包括转基因植物对作物遗传多样性的影响;转基因植物的外源基因向杂草和近缘野生种转移;转基因抗虫植物对目标害虫的影响。抗除草剂转基因植物对作物和杂草的影响,抗病毒转基因植物对病毒的影响;转基因植物对非目标生物的影响,对土壤生态系统的影响等．     

Projecting the effects of climate change on the distribution of maize races and their wild relatives in Mexico

Climate change is expected to be a significant threat to biodiversity, including crop diversity at centers of origin and diversification. As a way to avoid food scarcity in the future, it is important to have a better understanding of the possible impacts of climate change on crops. We evaluated these impacts on maize, one of the most important crops worldwide, and its wild relatives Tripsacum and Teocintes. Maize is the staple crop in Mexico and Mesoamerica, and there are currently about 59 described races in Mexico, which is considered its center of origin . In this study, we modeled the distribution of maize races and its wild relatives in Mexico for the present and for two time periods in the future (2030 and 2050), to identify the potentially most vulnerable taxa and geographic regions in the face of climate change. Bioclimatic distribution of crops has seldom been modeled, probably because social and cultural factors play an important role on crop suitability. Nonetheless, rainfall and temperature still represent a major influence on crop distribution pattern, particularly in rainfed crop systems under traditional agrotechnology. Such is the case of Mexican maize races and consequently, climate change impacts can be expected. Our findings generally show significant reductions of potential distribution areas by 2030 and 2050 in most cases. However, future projections of each race show contrasting responses to climatic scenarios. Several evaluated races show new potential distribution areas in the future, suggesting that proper management may favor diversity conservation. Modeled distributions of Tripsacum species and Teocintes indicate more severe impacts compared with maize races. Our projections lead to in situ and ex situ conservation recommended actions to guarantee the preservation of the genetic diversity of Mexican maize.     

Enhancing the Conservation of Crop Wild Relatives in England

Humans require resilient, rapidly renewable and sustainable supplies of food and many other plant-derived supplies. However, the combined effects of climate change and population growth compromise the provision of these supplies particularly in respect to global food security. Crop wild relatives (CWR) contain higher genetic diversity than crops and harbour traits that can improve crop resilience and yield through plant breeding. However, in common with most countries, CWR are poorly conserved in England. There is currently no provision for long-term CWR conservation in situ, and comprehensive ex situ collection and storage of CWR is also lacking. However, there is a commitment to achieve their conservation in England’s Biodiversity Strategy and the UK has international commitments to do so as part of the Global Plant Conservation Strategy. Here, we identify a series of measures that could enhance the conservation of English CWR, thereby supporting the achievement of these national and international objectives. We provide an inventory of 148 priority English CWR, highlight hotspots of CWR diversity in sites including The Lizard Peninsula, the Dorset coast and Cambridgeshire and suggest appropriate sites for the establishment of a complementary network of genetic reserves. We also identify individual in situ and ex situ priorities for each English CWR. Based on these analyses, we make recommendations whose implementation could provide effective, long-term conservation of English CWR whilst facilitating their use in crop improvement.     

Phylogenetic measures of biodiversity uncover pteridophyte centres of diversity and hotspots in Tuscany

Biodiversity studies traditionally use species as their analysis unit. However, observed biodiversity is not necessarily an indicator of significant biodiversity and therefore, should not be used alone, particularly when the results will be employed for conservation planning. Here, we examine pteridophyte diversity in Tuscany using 4668 geo-referenced pteridophyte records stored in Wikiplantbase #Toscana and calculating standard richness measures and phylogenetic indices; in addition, we assessed the environmental predictors of each diversity metric. Finally, we identified which areas hosting significantly high diversity are not adequately covered by protected areas or intersected by human activities. Although considerable diversity is distributed along Tuscany within areas traditionally recognised as biodiversity hotspots, important areas of diversity are identified only after the application of randomisation tests and through the phylogenetic metrics. Topographic ruggedness resulted the single most important variable predicting high value of all indices; temperature seasonality and temperature continentality resulted the secondary explanatory variables with a significant negative effect on most diversity indices.     

Spatial covariance between ecosystem services and biodiversity pattern at a national scale (France)

We present at a national-scale estimates of spatial covariance between areas important for ecosystem services (ES) and biodiversity, at a fixed spatial scale in France. We calculated different diversity and community metrics for common bird communities: taxonomic diversity (TD), functional diversity (FD), community specialization index (CSI), trophic index (TI), phylogenetic diversity (PD) and community evolutionary distinctiveness (CED). The ES multifunctionality (ES_MF) was measured using a combination of ES evenness and overall ES estimator. Spatially explicit tests were used to compare the spatial patterns of ES and diversity metrics. Mixed models were used for comparisons.We found low spatial congruence between ES and both diversity and community metrics in France. However, we detected even opposite associations between ES and each biodiversity component. Crop production was negatively associated with CED, it was positively correlated with CSI. No positive associations were found between ES_MF and any diversity metric, independently of farming systems. The only significant association was negative: lower values of CED were associated with hotspots of ES_MF. We found also a negative effect of crop production on bird CED. The conservation implication is remarkable, because conservation policies focusing solely on the economic value of ES will fail to protect overall biodiversity.     

Congruent spatial patterns of species richness and phylogenetic diversity in karst flora: Case study of Primulina (Gesneriaceae)

The karst landform in southern China is renowned for its high levels of species diversity and endemism. Globally, karst ecosystems are under threat from unsustainable anthropogenic disturbance and climate changes and are among the most threatened ecosystems worldwide. In this study, we used the typical karst endemic genus in southern China, Primulina Hance, as a model to identify areas within the karst landform with high diversity and to investigate congruence between phylogenetic and species‐based measures of diversity. Using phylogenetic information and species distribution data, we measured geographical patterns of diversity with four metrics: species richness (SR), corrected weighted endemism (CWE), phylogenetic diversity (PD), and phylogenetic endemism (PE). Our results revealed a high spatial congruence among SR, PD, and PE, with hotspot areas identified in the Nanling Mountains (i.e., north Guangdong and northeast Guangxi) and southeast Yungui Plateau (i.e., north and southwest Guangxi), whereas the hotspots of CWE are comparatively uniform throughout the geographic extent. The categorical analysis of neo‐ and paleoendemism identified a pattern of mixed neo‐ and paleoendemism in numerous grid cells, suggesting that karst areas in southern China have acted as both “museums” and “cradles” of plant evolution. Conservation gap analysis of hotspots revealed that the majority of prioritized hotspots (>90%) of the genus are outside of protected areas, therefore indicating the limited effectiveness of national nature reserves for the karst flora. Overall, our results suggest that the karst flora merits more conservation attention and SR can be an effective surrogate to capture PD in conservation planning.     

A national approach for mapping and quantifying habitat-based biodiversity metrics across multiple spatial scales

Ecosystem services, i.e., services provided to humans from ecological systems have become a key issue of this century in resource management, conservation planning, and environmental decision analysis. Mapping and quantifying ecosystem services have become strategic national interests for integrating ecology with economics to help understand the effects of human policies and actions and their subsequent impacts on both ecosystem function and human well-being. Some aspects of biodiversity are valued by humans in varied ways, and thus are important to include in any assessment that seeks to identify and quantify the benefits of ecosystems to humans. Some biodiversity metrics clearly reflect ecosystem services (e.g., abundance and diversity of harvestable species), whereas others may reflect indirect and difficult to quantify relationships to services (e.g., relevance of species diversity to ecosystem resilience, cultural value of native species). Wildlife habitat has been modeled at broad spatial scales and can be used to map a number of biodiversity metrics. In the present study, we present an approach that (1) identifies mappable biodiversity metrics that are related to ecosystem services or other stakeholder concerns, (2) maps these metrics throughout a large multi-state region, and (3) compares the metric values obtained for selected watersheds within the regional context. The broader focus is to design a flexible approach for mapping metrics to produce a national-scale product. We map 20 biodiversity metrics reflecting ecosystem services or other aspects of biodiversity for all vertebrate species except fish. Metrics include species richness for all vertebrates, specific taxon groups, harvestable species (i.e., upland game, waterfowl, furbearers, small game, and big game), threatened and endangered species, and state-designated species of greatest conservation need, and also a metric for ecosystem (i.e., land cover) diversity. The project is being conducted at multiple scales in a phased approach, starting with place-based studies, then multi-state regional areas, culminating into a national-level atlas. As an example of this incremental approach, we provide results for the southwestern United States (i.e., states of Arizona, New Mexico, Nevada, Utah, and Colorado) and portions of two watersheds within this region: the San Pedro River (Arizona) and Rio Grande River (New Mexico). Geographic patterns differed considerably among metrics across the southwestern study area, but metric values for the two watershed study areas were generally greater than those for the southwestern region as a whole.     

基于DNA条形码评估西双版纳国家级自然保护区对樟科植物进化历史的保护

为评估西双版纳国家级自然保护区对樟科这一重要植物类群进化潜力的保护情况, 揭示将物种进化历史纳入生物多样性保护评估的重要性, 本研究通过对西双版纳地区长期的野外调查并查阅标本记录与文献资料, 整理出该地区樟科13属121种物种的具体分布信息, 以植物条形码ITS序列作为分子标记构建了反映整个西双版纳地区樟科植物系统发育关系的系统发育树。我们以此为基础, 从物种层面分析了各物种的进化特异性(evolutionary distinctiveness, ED), 从区域层面分析了自然保护区内、外以及32个行政乡镇的系统发育多样性(phylogenetic diversity, PD), 并结合物种丰富度(species richness, SR)与物种濒危等级, 综合探讨了西双版纳国家级自然保护区对樟科植物进化历史的保护情况。研究发现, 西双版纳国家级自然保护区仅拥有整个西双版纳地区54.5%的樟科物种数, 却保护了该地区樟科植物约88.8%的进化历史, 没有被列入保护范围但却拥有高系统发育多样性的区域有打洛镇、易武乡等。就物种而言, 进化特异性相对较高的19个物种中, 有5种(26.3%)在自然保护区内没有分布; 濒危等级高的54个物种中, 有20种(37.0%)在自然保护区没有分布, 同时拥有高进化特异性和濒危等级的物种仅有1种不在保护区内分布。结果表明, 虽然西双版纳国家级自然保护区对樟科这一植物类群的系统发育多样性以及高保护价值物种的保护较好, 但仍有部分重要樟科植物的进化历史没有涵盖在现有自然保护区范围内; 按照传统方法设定的自然保护区虽能在一定程度上保护樟科物种的进化历史, 但仍然存在与标准化系统发育多样性保护策略相矛盾的地方。因此, 今后在建立自然保护区时, 应将系统发育多样性考虑在内, 以保护生物多样性应对环境变化的潜力。     

Concave trade-off curves between crop production and taxonomic,functional and phylogenetic diversity of birds

In a context of land scarcity, food production and biodiversity conservation objectives compete for land. The shape of the relationship between these two objectives may be helpful to inform decision-making. However, the metrics used to evaluate this relationship have so far been restricted to species abundances and species richness, which give no information on possible consequences on ecosystem functioning or on evolution history. Indeed, the shapes of the relationship between food production and other diversity facets, such as functional diversity and phylogenetic diversity, have rarely been studied. We considered 3 diversity facets: taxonomic diversity, functional diversity and phylogenetic diversity. For each facet, several biodiversity metrics have been proposed. The objective of this work was to investigate whether the shape of the trade-off curve between food production and biodiversity metrics depended on the considered facet of biodiversity. Using data from the national agricultural statistics, we computed edible energy from crops and from livestock on a nation-wide gradient covering French agroecosystems. Using bird observation data provided by the French Breeding Bird Survey (FBBS), we computed 9 (3 for each facet) biodiversity metrics in 516 different sites of the FBBS. The trade-off curves were then computed using additive mixed models. All metrics decreased along a crop production gradient. For functional and taxonomic diversity metrics, the slope was steeper at high levels of production, suggesting that actions aiming at increasing local taxonomic or functional diversity may be more efficient in regions with highest crop production, if restoration follows the same trajectory as biodiversity loss. The decrease was steeper for functional diversity than for taxonomic diversity, suggesting that agriculture can reduce the functional diversity of birds more than their taxonomic diversity.     

Palm economic and traditional uses,evolutionary history and the IUCN Red List

The growing demand for natural resources to sustain human population has increased the loss and modification of natural habitats, enhancing the number of species threatened with extinction. Commonly tools such as Red Lists guide conservation actions and policies. However, Red Lists are based in population parameters, and important aspects of biodiversity such as phylogenetic diversity are not considered. Here we evaluated the amount of economic and traditional uses and evolutionary history of palms captured by the global IUCN Red List and the national Red Lists of Colombia and Madagascar. We estimated palms plant use diversity (PUD) and phylogenetic diversity (PD) for all species in the IUCN Red List and for each threat category at global and national scale. We also investigated if the number of uses, PUD and PD predict palm threat level. Species covered by IUCN Red List have lower PUD and PD than expected by chance. At global scale, palms with higher extinction risk have lower number of uses, PUD and PD. However, whereas in Colombia least concern species had lower PUD and PD, in Madagascar only Data Deficient species had lower PUD than expected by chance. Our findings highlight the need of palm specialists to expand the list of palms they have assessed and submit them for inclusion in Red Lists, enabling Red Lists to capture a more random sample of palm evolutionary history and economic uses. That would improve the success of biodiversity conservation actions by taking into account other aspects of biodiversity rather than taxonomic identity.     

Phylogenetic diversity metrics for ecological communities: integrating species richness, abundance and evolutionary history

Phylogenetic information is increasingly being used to understand the assembly of biological communities and ecological processes. However, commonly used metrics of phylogenetic diversity (PD) do not incorporate information on the relative abundances of individuals within a community. In this study, we develop three indices of PD that explicitly consider species abundances. First, we present a metric of phylogenetic-abundance evenness that evaluates the relationship between the abundance and the distribution of terminal branch lengths. Second, we calculate an index of hierarchical imbalance of abundances at the clade level encapsulating the distribution of individuals across the nodes in the phylogeny. Third, we develop an index of abundance-weighted evolutionary distinctiveness and generate an entropic index of phylogenetic diversity that captures both information on evolutionary distances and phylogenetic tree topology, and also serves as a basis to evaluate species conservation value. These metrics offer measures of phylogenetic diversity incorporating different community attributes. We compare these new metrics to existing ones, and use them to explore diversity patterns in a typical California annual grassland plant community at the Jasper Ridge biological preserve.
Ecology Letters (2010) 13: 96–105