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1.
Efforts to protect the remaining Araucaria Forest fragments in Southern Brazil have focused on large forests dominated by the threatened species Araucaria angustifolia. However, such an approach can miss significant biodiversity by ignoring smaller forest fragments scattered throughout the landscape, many of which exist on small farms. Here, I evaluate the method used to define a set of natural reserves in Southern Brazil to assess if it captures and preserves the significant biodiversity that exists in this unique biome. I used a relatively simple field sampling methodology and statistical analyses to evaluate floristic and structural parameters, comparing tree species diversity within a large forest fragment (with and without A. angustifolia dominance) to smaller fragments in the surrounding landscape. While stands dominated by A. angustifolia showed primary forest‐like physiognomy, they did not have the levels of diversity expected for old‐growth forests. Traditional forestry parameters, especially basal area and number of individuals, are useful for differentiating forest types in terms of structure. While no single diversity index provides a complete picture of the composition and variation of diversity in forest fragments, when taken together and assessed using extrapolation and comparative statistics, they provide a meaningful method for comparing and identifying high priority areas for conservation. Future conservation strategies should look to alternative approaches for assessing biodiversity across the landscape, while including small‐scale landowners in conservation efforts.  相似文献   

2.
Question: How do studies of the distribution of genetic diversity of species with different life forms contribute to the development of conservation strategies? Location: Old‐growth forests of the southeastern United States. Methods: Reviews of the plant allozyme literature are used to identify differences in genetic diversity and structure among species with different life forms, distributions and breeding systems. The general results are illustrated by case studies of four plant species characteristic of two widespread old‐growth forest communities of the southeastern United States: the Pinus palustris – Aristida stricta (Longleaf pine – wiregrass) savanna of the Coastal Plain and the Quercus – Carya – Pinus (Oak‐hickory‐pine) forest of the Piedmont. Genetic variation patterns of single‐gene and quantitative traits are also reviewed. Results: Dominant forest trees, represented by Pinus palustris(longleaf pine) and Quercus rubra (Northern red oak), maintain most of their genetic diversity within their populations whereas a higher proportion of the genetic diversity of herbaceous understorey species such as Sarracenia leucophylla and Trillium reliquum is distributed among their populations. The herbaceous species also tend to have more population‐to‐population variation in genetic diversity. Higher genetic differentiation among populations is seen for quantitative traits than for allozyme traits, indicating that interpopulation variation in quantitative traits is influenced by natural selection. Conclusion: Developing effective conservation strategies for one or a few species may not prove adequate for species with other combinations of traits. Given suitable empirical studies, it should be possible to design efficient conservation programs that maintain natural levels of genetic diversity within species of conservation interest.  相似文献   

3.
Habitat loss represents one of the main threats to tropical forests, which have reached extremely high rates of species extinction. Forest loss negatively impacts biodiversity, affecting ecological (e.g., seed dispersal) and genetic (e.g., genetic diversity and structure) processes. Therefore, understanding how deforestation influences genetic resources is strategic for conservation. Our aim was to empirically evaluate the effects of landscape‐scale forest reduction on the spatial genetic structure and gene flow of Euterpe edulis Mart (Arecaceae), a palm tree considered a keystone resource for many vertebrate species. This study was carried out in nine forest remnants in the Atlantic Forest, northeastern Brazil, located in landscapes within a gradient of forest cover (19–83%). We collected leaves of 246 adults and 271 seedlings and performed genotyping using microsatellite markers. Our results showed that the palm populations had low spatial genetic structure, indicating that forest reduction did not influence this genetic parameter for neither seedlings nor adults. However, forest loss decreased the gene flow distance, which may negatively affect the genetic diversity of future generations by increasing the risk of local extinction of this keystone palm. For efficient strategies of genetic variability conservation and maintenance of gene flow in E. edulis, we recommend the maintenance of landscapes with intermediary to high levels of forest cover, that is, forest cover above 40%.  相似文献   

4.
We integrate analyses of spatial association with empirical measures of juvenile performance to develop a strategy for Araucaria forest restoration in Brazil. Because pioneer species can differentially facilitate or inhibit target species, we measure native Araucaria angustifolia and exotic Pinus taeda responses to two common pioneer species, Baccharis uncinella and Vernonia discolor in a clear-cut pine plantation. P. taeda establishment and growth was greater than that of A. angustifolia in all treatments, showing its potential for invasiveness. B. uncinella showed significant positive spatial associations with P. taeda and negative spatial associations with A. angustifolia. V. discolor showed significant negative spatial associations with P. taeda but neutral spatial associations with A. angustifolia, it also supported a higher diversity of native species under its canopy than B. uncinella. Experimental results show that these patterns are due to differential establishment restrictions imposed by both pioneers on target species. We conclude that B. uncinella promotes pine invasion while V. discolor restrains it. We suggest strategies for Araucaria forest restoration and highlight the broad applicability of our approach to restoration programs.  相似文献   

5.
  1. Recent advances in molecular methods foster the documentation of small spatial scale biological diversity over large geographical areas. These advances allow to correctly record α-diversity, but also enable biomonitoring that describes intraspecific molecular diversity, providing valuable insights into the contemporary history of species. Such information is essential for the accurate monitoring of freshwater communities and provides a promising tool to identify conservation priorities at various spatial scales.
  2. Here, we combined morphological species determinations with genetic characterisation via DNA barcoding and species distribution modelling. We aimed to investigate whether closely related amphipod species occupying overlapping ecological niches and occurring in partial sympatry, demonstrate similar spatial patterns of intraspecific genetic diversity and share comparable population histories. Therefore, we characterised the amphipod fauna within the Kinzig catchment (1,058 km2, Hesse, Central Germany) that is a tributary of the Main River and part of the long-term ecological research network using genetics.
  3. Our genetic analysis revealed two more taxonomic entities than previously known. The most common species was Gammarus fossarum clade 11 (or type B), followed by Gammarus roeselii clade C, Gammarus pulex clade D, G. pulex clade B and a very rare previously unknown lineage within the G. fossarum-species complex, which we refer to as G. fossarum clade RMO. These five taxa differed in their intraspecific genetic diversity, with G. fossarum clade 11 demonstrating the highest diversity and having a prominent small-scale pattern with endemic haplotypes in headwater regions. Distributions were predicted for the three most abundant molecularly identified species.
  4. The upstream reaches maintained high intraspecific α- and β-diversity, pointing towards a more complex population structure of G. fossarum clade 11. This highlights the importance of considering intraspecific diversity for the conservation of individual species. DNA-based species distribution models shed light on species-specific habitat preferences, and showed spatial distribution patterns that supported ecological inference and conservation management. Barcoding specimens prior to modelling can increase robustness and performance of distribution models as juveniles can be incorporated, and cryptic species complexes disentangled.
  5. Our integrative study contributes to the further development of science-informed and holistically considered effective conservation measures. Some poorly dispersing hololimnic species may serve as representatives for our understanding of the natural history of the local communities in headwater regions—and their protection. Intraspecific genetic diversity should be considered in conservation management decisions as it can provide valuable information on past and present population demography, connectivity, and recovery processes of species—information that rarely can be achieved by traditional monitoring approaches.
  相似文献   

6.
Tropical agro-forest landscapes are potentially valuable reserves of forest genetic resources for forestry and restoration of degraded forests. The Dipterocarpaceae is a dominant Southeast Asian family of tree species of global significance for the tropical timber industry. Very little information exists about how effective human modified landscapes are for conserving genetic diversity in dipterocarp species. This study provides a baseline for understanding how fragmented agro-forest landscapes in India sustain forest genetic resources in an endemic dipterocarp tree. We compare genetic diversity and fine-scale spatial genetic structure (FSGS) in the threatened tree species Vateria indica within an isolated and a continuous forest site in the Western Ghats, South India. We place these results in the context of dipterocarps from both the Seychelles and Borneo. Parentage analysis of 694 progeny using twelve nuclear microsatellite markers is applied to estimate pollen and seed dispersal. Using a nursery trial we evaluate effects of inbreeding on growth performance. Our results show that levels of FSGS, and gene dispersal are comparable between a small isolated and a large continuous site of V. indica. Realized long-distance pollen flow into the isolated patch appears to help maintaining genetic diversity. The nursery experiment suggests that selection favours outbred progeny. Individuals of V. indica in close proximity appear less related to each other than in another highly fragmented and endangered dipterocarp species from the Seychelles, but more related than in three dipterocarp species studied in continuous forest in Borneo. We discuss the wider implications of our findings in the context of conservation and restoration of dipterocarp forest genetic resources in fragmented populations.  相似文献   

7.
In order to determine the implications of including planted populations in conservation planning, we investigate the structure and genetic diversity, mating system, and effective population size within families in three planted and one natural Araucaria angustifolia populations. The study area is a Brazilian National Forest in southern Brazil, established in the 1950s. Genetic analysis was investigated using nine allozyme loci. Significant and positive fixation index was detected for the adults of all studied populations. Although we observed lower levels of genetic diversity and biparental inbreeding in some populations, their pattern of mating, similar to that expected in panmixia, indicates that all populations can be used in conservation planning. Furthermore, the presence of unique alleles and the significant genetic differentiation among all adult populations (F ST = 0.404) reinforces that all populations are important conservation resources. The average paternity correlation was high in almost all populations, showing that open-pollinated families are composed of mixtures of half- and full-sibs. With regards to conservation strategies, our results suggest that seed collection from at least 133 seed trees is necessary to retain a reference effective population size of 500. Our results confirm that the planted Araucaria forests in southern Brazil can be useful as a genetic resource for conservation, breeding and reforestation strategies for this threatened species.  相似文献   

8.
The Araucariaceae family has only two species in South America: Araucaria angustifolia and Araucaria araucana. Both species are mainly used for timber and have been overexploited in the past. Currently, they are found as fragmented populations and are classified under the International Union for Conservation of Nature and Natural Resources (IUCN) guidelines as vulnerable species. Population fragmentation may seriously affect the genetic diversity of these two species of Araucariaceae and can consequently lead to decreased survival. To better understand the genetic structure of these South American Araucaria species, eight nuclear microsatellites are reported: six new microsatellites loci developed based on a membrane enrichment procedure and two microsatellites loci transferred from the related species, Araucaria cunninghamii.  相似文献   

9.
Climate change affects both habitat suitability and the genetic diversity of wild plants. Therefore, predicting and establishing the most effective and coherent conservation areas is essential for the conservation of genetic diversity in response to climate change. This is because genetic variance is a product not only of habitat suitability in conservation areas but also of efficient protection and management. Phellodendron amurense Rupr. is a tree species (family Rutaceae) that is endangered due to excessive and illegal harvesting for use in Chinese medicine. Here, we test a general computational method for the prediction of priority conservation areas (PCAs) by measuring the genetic diversity of P. amurense across the entirety of northeast China using a single strand repeat analysis of twenty microsatellite markers. Using computational modeling, we evaluated the geographical distribution of the species, both now and in different future climate change scenarios. Different populations were analyzed according to genetic diversity, and PCAs were identified using a spatial conservation prioritization framework. These conservation areas were optimized to account for the geographical distribution of P. amurense both now and in the future, to effectively promote gene flow, and to have a long period of validity. In situ and ex situ conservation, strategies for vulnerable populations were proposed. Three populations with low genetic diversity are predicted to be negatively affected by climate change, making conservation of genetic diversity challenging due to decreasing habitat suitability. Habitat suitability was important for the assessment of genetic variability in existing nature reserves, which were found to be much smaller than the proposed PCAs. Finally, a simple set of conservation measures was established through modeling. This combined molecular and computational ecology approach provides a framework for planning the protection of species endangered by climate change.  相似文献   

10.
This study sought to investigate land‐snail diversity, abundance and distribution in Arabuko Sokoke forest. Sampling was done using standard timed direct search and litter sample methods. In total, 25 species and 1263 specimens were recorded. The 25 species rank Arabuko Sokoke forest as the second richest coastal forest in land snails in East Africa. The 25 species, however, are not uniformly distributed across the forest. The majority of the snails were localized with low levels of abundance. Eight species were restricted to one forest type, whereas those shared among forest types tended to concentrate in one forest type. Only five species, Gulella radius, Gulella foveolata, Gonaxis kibweziensis, Pseudoglessula biovini and Opeas gracilis, were widespread. The highest snail diversity was recorded in the mixed forest, implying that special conservation of this habitat is necessary for retention of the broadest molluscan diversity. The observation that some species rare in the mixed forest were recorded in excess from Brachystegia and Cynometra forest, further suggests that conservation of the entire A. Sokoke forest is critical for efficient molluscan conservation. Species recorded in low levels of abundance are probably declining and investigation on the snails' ecology to understand factors that influence the snails' diversity is recommended.  相似文献   

11.
Conversion of diverse native forests to tree monocultures remains an ongoing, worldwide threat to biodiversity. Although the effects of forest conversion have been studied in a wide range of taxonomic groups, the effects on macrofungal communities remain poorly understood. We sampled macrofungal fruiting bodies in the National Forest of São Francisco de Paula in Southern Brazil over 12 months in four different forest habitats: native Araucaria angustifolia forest, A. angustifolia plantation, Pinus taeda or P. elliottii plantation, and Eucalyptus saligna plantation. The distribution of macrofungal species in different functional groups varied among habitats: the macrofungal species composition of the A. angustifolia plantation was more similar to that of the native forest, while the exotic Pinus or Eucalyptus plantations were less similar to the native forest. The conversion of native forest to exotic tree plantations reduced the number of macrofungal decomposer species, probably due to changes in substrate availability and quality. We conclude that fungal diversity and ecosystem functionality require the preservation of native, mature forests and suggest a shift of Brazilian forestry guidelines to encourage the plantations of native species instead of exotics.  相似文献   

12.
The impact of fragmentation by human activities on genetic diversity of forest trees is an important concern in forest conservation, especially in tropical forests. Dysoxylum malabaricum (white cedar) is an economically important tree species, endemic to the Western Ghats, India, one of the world's eight most important biodiversity hotspots. As D. malabaricum is under pressure of disturbance and fragmentation together with overharvesting, conservation efforts are required in this species. In this study, range‐wide genetic structure of twelve D. malabaricum populations was evaluated to assess the impact of human activities on genetic diversity and infer the species’ evolutionary history, using both nuclear and chloroplast (cp) DNA simple sequence repeats (SSR). As genetic diversity and population structure did not differ among seedling, juvenile and adult age classes, reproductive success among the old‐growth trees and long distance seed dispersal by hornbills were suggested to contribute to maintain genetic diversity. The fixation index (FIS) was significantly correlated with latitude, with a higher level of inbreeding in the northern populations, possibly reflecting a more severe ecosystem disturbance in those populations. Both nuclear and cpSSRs revealed northern and southern genetic groups with some discordance of their distributions; however, they did not correlate with any of the two geographic gaps known as genetic barriers to animals. Approximate Bayesian computation‐based inference from nuclear SSRs suggested that population divergence occurred before the last glacial maximum. Finally we discussed the implications of these results, in particular the presence of a clear pattern of historical genetic subdivision, on conservation policies.  相似文献   

13.
Abstract Araucaria Forest expansion over grassland takes place under wet climate conditions and low disturbance and it is hypothesized that isolated trees established on grassland facilitate the establishment of forest woody species beneath their canopies. Forest with Araucaria angustifolia is a particular type of Brazilian Atlantic Forest and the main forest type on the highland plateau in south Brazil, often forming mosaics with natural Campos grassland. The objectives of this paper were to evaluate the role of isolated shrubs and trees as colonization sites for seedlings of Araucaria Forest woody species on grassland, to determine which species function as preferential nurse plants in the process and the importance of vertebrate diaspore dispersal on the structure of seedling communities beneath nurse plants. The study was conducted in São Francisco de Paula, Rio Grande do Sul State, where we sampled isolated shrubs and trees in natural grassland near Araucaria Forest edges. Seedlings were counted and identified, and seedling diaspore dispersal syndromes, size and colour were registered. We detected 11 woody species with a potential role in nucleating grassland colonization by forest species. Beneath the canopies of nurse plants more forest species seedlings were found compared with open field grassland and the seedlings had diaspores mostly dispersed by vertebrates. Also, more seedlings were found under the canopy of A. angustifolia than beneath other nurse plant species. We conclude that A. angustifolia trees established on grassland act as nurse plants, by attracting disperser birds that promote colonization of the site by other forest species seedlings, and that under low level of grassland disturbance, conservation of frugivorous vertebrate assemblages may increase forest expansion over natural grassland and also facilitate the regeneration of degraded forest areas.  相似文献   

14.
Climate change, alien species, and use of land for intensive farming and development are causing severe threat to the plant genetic diversity worldwide. Hence, conservation of biodiversity is considered fundamental and also provides the livelihoods to millions of people worldwide. Medicinal plants play a key role in the treatment of a number of diseases, and they are only the source of medicine for majority of people in the developing world. The tropical regions of the world supply the bulk of current global demand for “natural medicine,” albeit with increasing threat to populations in the world and its genetic diversity. India is a major center of origin and diversity of crop and medicinal plants. India poses out 20,000 species of higher plants, one third of it being endemic and 500 species are categorized to have medicinal value. The Western Ghats is one of the major repositories of medicinal plants. It harbors around 4,000 species of higher plants of which 450 species are threatened. Currently, the number of species added to the red list category in this region is increasing, and the valuable genetic resources are being lost at a rapid rate. Demand for medicinal plants is increasing, and this leads to unscrupulous collection from the wild and adulteration of supplies. Providing high-quality planting material for sustainable use and thereby saving the genetic diversity of plants in the wild is important. During the last 25 years of intensive research, Tropical Botanic Garden and Research Institute has developed in vitro protocol for rapid regeneration and establishment of about 40 medicinally important rare and threatened plants of Western Ghats. In situ conservation alone would not be effective in safeguarding these important species. Thus, utilizing the biotechnoligical approach to complement ex situ conservation program is becoming vital. Propagating biotechnology tools in plant conservation program is a prerequisite to succeed in sustainable use and to complement the existing ex situ measures. In addition to propagation, storage of these valuable genetic resources is equally important. In vitro slow growth of 35 species and cryopreservation using embryo/meristem/seed in 20 different species of rare medicinal plants of this region is accomplished. Plants developed in vitro of ten medicinal plants, which have restricted distribution, were reintroduced in the natural habitat as well.  相似文献   

15.
16.

Aim

Deforestation of the Atlantic Forest of eastern Paraguay has been recent but extensive, resulting in a fragmented landscape highly influenced by forest edges. We examined edge effects on multiple dimensions of small mammalian diversity.

Location

Forest fragments of eastern Paraguayan Atlantic Forest.

Methods

We trapped small mammal species at different distances from the forest edge (DTE) in reserves and estimated multiple dimensions of diversity per site. Similarity analysis identified species clusters that best described the patterns of diversity across reserves. Multivariate ordination and linear mixed models were used to determine the influence of DTE on various dimensions of small mammal diversity.

Results

There was an increase in richness and abundance along a DTE gradient, and remnants with higher edge:area ratios showed higher richness and abundance, independent of remnant size. Species at edges were generalists, open-habitat species or exotic species (spillover effect). We found higher phylogenetic diversity and functional richness and divergence towards forest edges. Spillover of non-forest and invasive species best explained richness, generalist forest species best explained total abundance, abundance of Hylaeamys megacephalus best explained diversity and evenness metrics and the presence of Marmosa paraguayana best explained various phylogenetic diversity models. None of the models that included megafauna or social factors were shown to be important in explaining patterns as a function of DTE.

Main Conclusions

We found strong support for a spillover effect and mixed support for complementary resource use and enhanced habitat resources associated with ecotones. Generalists characterized edge assemblages but not all generalists were equivalent. Edges showed more phylogenetically and functionally distinct assemblages than the interior of remnants. There was a conservation of functional diversity; however, open-habitat species, habitat generalists and exotic species boosted diversity near forest edges. Mechanisms governing diversity along forest edges are complex; disentangling those mechanisms necessitates the use of multiple dimensions of diversity.  相似文献   

17.
Knowledge of the levels of genetic diversity maintained in natural populations can play a central role in conservation programmes, particularly in threatened habitats or species. Fluctuations in population size can lead to loss of variation and, consequently, increase the risk of extinction. We have examined whether such a genetic bottleneck has occurred in populations of two species in the seagrass genus Zostera, which are believed to have been affected by an outbreak of wasting disease at the start of the last century. A test for heterozygote excess at five nuclear microsatellite loci did not suggest the occurrence of a genetic bottleneck, but analysis of seven chloroplast microsatellite loci and sequence data from two regions did suggest a bottleneck in the chloroplast genome. Extremely low levels of between-population diversity suggest that all subpopulations can be treated as a single management unit for each species. Comparable levels of nuclear genetic diversity were found in the three populations of the primarily sexual Zostera marina var. angustifolia studied but a wider range of within-population diversity was found in Zostera noltii, which displays both sexual and vegetative reproductive strategies. This may be due to an increase in sexual recruitment due to localised fresh water inflow into the study site near to the most diverse population. Such populations should be prioritised as source material for any replanting or remediation due to natural or anthropogenic loss of Zostera beds in the area.  相似文献   

18.
Omphalogramma souliei Franch. is an endangered perennial herb only distributed in alpine areas of SW China. ISSR markers were applied to determine the genetic variation and genetic structure of 60 individuals of three populations of O. souliei in NW Yunnan, China. The genetic diversity at the species level is low with P=42.5% (percentage of polymorphic bands) and Hsp=0.1762 (total genetic diversity). However, a high level of genetic differentiation among populations was detected based on different measures (Nei's genetic diversity analysis: Gst=0.6038; AMOVA analysis: Fst=0.6797). Low level of genetic diversity within populations and significant genetic differentiation among populations might be due to the mixed mating system in which xenogamy predominated and autogamy played an assistant role in O. souliei. The genetic drift due to small population size and limited current gene flow also resulted in significant genetic differentiation. The assessment of genetic variation and differentiation of the endangered species provides important information for conservation on a genetic basis. Conservation strategies for this rare endemic species are proposed.  相似文献   

19.
We investigated aquatic plant diversity by conducting the field investigation and collecting the published data in the arid regions of Northwest China. Two hundred and twenty four taxa of vascular aquatic plants representing 64 genera and 34 families occur in this area, 8.48% of which are endemic. Among these, 1 genus and 6 species were new state records and 1 family, 9 genera and 29 species were new area records. Typhaceae, Potamogetonaceae, Juncaginaceae and Haloragaceae were the most frequent families (considering relative frequency of occurrence), whereas Cyperaceae, Potamogetonaceae and Ranuncnlaceae are the most species-rich. The most frequent genera were Typha, Potamogeton, and Triglochin, and the most species-rich were Potamogeton, Eleocharis and Scirpus. The most frequent species are Triglochin palustre, Myriophyllum spicatum, Potamogeton pectinatus and Typha angustifolia. Aquatic plants diversity is distributed unevenly in the region. The maximum species occurs in Dzungarian basin while the least species in Hexi corridor. The aquatic flora in arid zone of China is not distinctive although some endemic species are found, most species are widely distributed. Local aquatic plants diversity can be influenced by many factors such as hydrological alteration, habitat loss, over-grazing, high human population pressure, global climate change, an inappropriate economic development policy. Among them, the largest threat to aquatic plants biodiversity may be habitat loss due to hydrological alteration. In order to conserve the aquatic plants biological resources and biodiversity in this region, some strategies and measures must be suggested including strengthening scientific research and biodiversity education in the local people, balancing economic development and ecological conservation, and enhancing governmental assistance and subsidy to the local residents.  相似文献   

20.
Genetic resources of forest trees are considered as a key factor for the persistence of forest ecosystems because the ability of tree species to survive under changing climate depends strongly on their intraspecific variation in climate response. Therefore, utilizing available genetic variation in climate response and planting alternative provenances suitable for future climatic conditions is considered as an important adaptation measure for forestry. On the other hand, the distribution of adaptive genetic diversity of many tree species is still unknown and the predicted shift of ecological zones and species’ distribution may threaten forest genetic resources that are important for adaptation. Here, we use Norway spruce in Austria as a case study to demonstrate the genetic variation in climate response and to analyse the existing network of genetic conservation units for its effectiveness to safeguard the hotspots of adaptive and neutral genetic diversity of this species. An analysis of the climate response of 480 provenances, clustered into 9 groups of climatically similar provenances, revealed high variation among provenance groups. The most productive and promising provenance clusters for future climates originate from three regions that today depict the warmest and driest areas of the natural spruce distribution in Austria. Gap analysis of the Austrian genetic conservation units in the EUFGIS Portal suggests adequate coverage of the genetic hotspots in southern parts of Austria, but not in eastern and northern Austria. Therefore conservation measures and sustainable utilization of the valuable genetic resources in these regions need to be expanded to cover their high adaptive genetic variation and local adaptation to a warmer climate. The study shows that current conservation efforts need to be evaluated for their effectiveness to protect genetic resources that are important for the survival of trees in a future climate.  相似文献   

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