首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
Large‐scale ecological restoration programs across the world involve a voluminous demand for native seeds of diverse native plant species. In this article, we explore how institutional systems have operated and impacted native seed supply in Brazil. Native seed supply for restoration is essentially a community‐based activity which faces broad barriers to operating within regulations because of requirements for excessive and costly technical documentation, scarcity of seed laboratories, and lack of instructions for native seed quality testing. Although decentralized seed networks have stimulated arrangements for local organizations to promote seed supply, policies constrain the development of local capacities and the ongoing sustainability of these organizations. These conditions have resulted in a vast network of informal collectors and producers who are largely “invisible” and unknown to the regulatory authorities. Policies have decentralized responsibilities from the state without devolving decision‐making power to the multiple stakeholders engaged in policy elaboration. The policies maintain the centralized regulation of native seed supply. After examining Brazilian seed networks' experiences and conducting discussions with stakeholders and experts, we suggest adapting the current regulations to more local level contexts, encompassing the following strategies: (1) ensuring native seed origin and identity; (2) relaxation of the laboratory accreditation process for native seed quality assurance; (3) fostering seed markets for restoration; (4) research to provide technological innovation; (5) supporting local, diverse, and small seed‐based businesses.  相似文献   

2.
Large quantities of diverse and appropriately adapted native plant germplasm are required to facilitate restoration globally, yet shortages can prevent restorations from attaining desired species diversity and structure. An extensive native plant industry has developed in the United States to help meet these demands, yet very little is known about its capacity to support germplasm needs. To better understand current capacity and germplasm availability, we report results of the first comprehensive and quantitative assessment of the native plant industry in the United States, which includes at least 841 vendors nationwide and the species they make available for restoration. We synthesized lists of commercially available species from native plant vendors across the United States and identified gaps in species availability to inform germplasm research, development, and production. Of the approximately 25,000 vascular plant taxa native to the United States, 26% are sold commercially, with growth form, conservation status, distribution, and taxonomy significantly predicting availability. In contrast, only 0.07% of approximately 3,000 native nonvascular taxa are sold commercially. We also investigated how demand for germplasm to support high‐quality restoration efforts is met by vendors in the Midwestern tallgrass prairie region, which has been targeted extensively by restoration efforts for decades. In this well‐developed native plant market, 74% of more than 1,000 target species are commercially available, often from vendors that advertise genetically diverse, locally sourced germplasm. We make recommendations to build on the successes of regional markets like the tallgrass prairie region, and to fill identified gaps, including investing in research to support production, ensuring more consistent and clear demand, and fostering regional collaboration.  相似文献   

3.
The ever increasing demand for native plants and seed for use in restoration and revegetation has created a sizable industry. The large‐scale production and planting of native plants have given rise to a suite of ecological concerns including collection impacts, genetic diversity, and provenance. This study examines the practices and beliefs of 12 restoration plant production companies in Colorado with regard to arising ecological issues and identifies where further research is needed. We found that native seed collection in Colorado was largely unregulated and unmonitored and impacts were unknown. Maintaining genetic diversity in restoration materials is costly and does not have universal support. The use of provenance material (or local ecotypes) was hotly contested with strong and sound arguments on both sides of the issue. Procurement of pure ecotypes was difficult because of the variety of institutions involved in production and complications such as artificial selection and cross‐pollination.  相似文献   

4.
Local knowledge is becoming increasingly important in primary health care projects. However, these projects often incorporate local knowledge in an uncritical manner. One area where this is apparent is in the lack of attention paid to the gendered nature of local knowledge. I use one example, women's knowledge and use of medicinal plants in a low-income community in the Brazilian Amazon, to illustrate the links among authority, knowledge, and gender. In this article I argue that policy makers must pay attention to the relationships among authority, gender, and local knowledge and examine how the use of local knowledge in development strategies can affect existing (gendered) power relationships. Women's roles as managers of household health (which includes medicinal plant use) are a source of authority for them. Because of that, the way in which local knowledge is incorporated into primary health care programs can have a significant impact on women's authority.  相似文献   

5.
The use of local, native plant materials is now common in restoration but testing for polyploidy in seed sources is not. Diversity in cytotypes across a landscape can pose special seed transfer challenges, because the methods used to determine genetically appropriate materials for seed transfer do not account for cytotypic variation. This lack of consideration may result in mixing cytotypes through revegetation, which could reduce long‐term population viability. We surveyed nine populations of a native bunchgrass, Pseudoroegneria spicata, in three EPA Level III Ecoregions in the western United States to determine the frequency of polyploidy, whether there are differences in traits (phenotype, fecundity, and mortality) among plants of different cytotypes, and whether cytotype frequency varies among ecoregions. We assessed trait variation over 2 years in a common garden and determined ploidy using flow cytometry. Polyploidy and mixed cytotype populations were common, and polyploids occurred in all ecoregions. Four of the nine populations were diploid. The other five had tetraploids present: three had only tetraploid individuals whereas two had mixed diploid/tetraploid cytotypes. There was significant variation in traits among cytotypes: plants from tetraploid populations were larger than diploid or mixed populations. The frequency and distribution of cytotypes make it likely that seed transfer in the study area will inadvertently mix diploid and polyploid cytotypes in this species. The increasing availability of flow cytometry may allow ploidy to be incorporated into native plant materials sourcing and seed transfer.  相似文献   

6.
以昆明市获全国绿化模范单位的四所高校校园绿地内稳定的植物群落为研究对象,采用典型抽样方法分析植物群落区系的组成成分、分布区类型以及植物的乡土性。结果表明,四所高校校园绿地植物群落物种丰富,有97科172属,共计281种维管束植物;植物地理成分有从温带、亚热带向热带过渡,能代表地带性植被的组成特征。调查表明云南的乡土植物有待进一步开发应用。  相似文献   

7.
Reclamation of highly disturbed lands typically includes establishing fast‐growing, non‐native plants to achieve rapid ground cover for erosion control. Establishing native plant communities could achieve ecosystem functions beyond soil erosion, such as providing wildlife habitat. Pipelines, or other disturbed corridors through a landscape, present unique challenges for establishing native plant communities given the heterogeneity of soil environments and invasive plant propagule pressure. We created two structural equation models to address multiple related hypotheses about the influence of soil pH on plant community composition (current diversity and vegetative cover of the original restoration seed mix and background flora, and invasive plant density during mix establishment and current density) of a highly disturbed landscape corridor restored with native species. To test our hypotheses we conducted a plant survey on a gas pipeline crossing two state forests in the north‐central Appalachians that had been seeded with a native‐based mixture 8 years prior. Low soil pH was a strong predictor of density of the invasive annual plant, Microstegium vimineum, and had resulted in lower species diversity and cover of the seeded mix. Overall, our data provide evidence that native‐based grass and forb mixtures can establish and persist on a wide range of soil environments and thrive in competition with invasive plants in moderately acidic to neutral soils. Advancing knowledge on restoration methods using native species is essential to improving restoration practice norms to incorporate multifunctional ecological goals.  相似文献   

8.
  • Large‐scale restoration programmes in the tropics require large volumes of high quality, genetically diverse and locally adapted seeds from a large number of species. However, scarcity of native seeds is a critical restriction to achieve restoration targets.
  • In this paper, we analyse three successful community‐based networks that supply native seeds and seedlings for Brazilian Amazon and Cerrado restoration projects. In addition, we propose directions to promote local participation, legal, technical and commercialisation issues for up‐scaling the market of native seeds for restoration with high quality and social justice.
  • We argue that effective community‐based restoration arrangements should follow some principles: (i) seed production must be based on real market demand; (ii) non‐governmental and governmental organisations have a key role in supporting local organisation, legal requirements and selling processes; (iii) local ecological knowledge and labour should be valued, enabling local communities to promote large‐scale seed production; (iv) applied research can help develop appropriate techniques and solve technical issues.
  • The case studies from Brazil and principles presented here can be useful for the up‐scaling restoration ecology efforts in many other parts of the world and especially in tropical countries where improving rural community income is a strategy for biodiversity conservation and restoration.
  相似文献   

9.
Invasive species have the potential to create positive feedbacks and push an ecosystem into an alternative state through a variety of mechanisms. Unless the drivers behind these feedbacks are understood, restoring a system to a more desirable state may not be possible. We used a long‐term vernal pool restoration project based out of Travis Airforce Base, Fairfield, CA, U.S.A. to examine natural pools dominated by either invasive or native plant communities, and restored pools predominately composed of invasive plants. We determined that plant community structure is drastically altered towards invasive grasses with the addition of a single centimeter of litter. In the absence of this litter layer, community structure was driven by a non‐native forb rather than native species. We also found that native plant‐dominated vernal pools have a longer inundation duration and are deeper compared to invasive‐dominated pools, regardless of construction status. These results suggest that once invasive grasses establish through lower inundation depths, their litter deposition can initiate a positive feedback to maintain an invasive alternative state. However, even after litter removal, non‐native forbs can replace the grasses causing a second alternative state still separate from the most desirable native dominated state. This study directly demonstrates that invasive species, and their positive feedbacks, may limit the success of ecological restoration. To effectively restore a system all constraints must be identified and removed before successful restoration can occur.  相似文献   

10.
《植物生态学报》2021,44(11):1095
菌根真菌共生是植物吸收养分的一个重要策略。外来植物可以干扰本地植物与菌根真菌的共生关系从而抑制本地植物生长, 这是近年来被发现的一种重要入侵机制, 在研究中得到日益广泛的关注。该文从以下几个方面着重综述这种入侵机制: 1)外来植物对本地植物菌根真菌的影响, 包括菌根真菌侵染率、菌根内部结构、根外菌丝的量、菌根真菌的群落组成、非菌根真菌的影响及网络结构; 2)外来植物对本地植物菌根真菌上述影响的机制, 包括资源竞争、化感作用和土壤肥力等生态机制以及相关的分子机制; 3)上述两个方面随入侵时间的变化格局。尽管干扰本地植物菌根真菌是一种重要的入侵机制, 但相对其他的入侵机制(例如天敌逃逸、新武器假说等)来说, 这类机制的研究目前仍很匮乏。鉴于此, 该文提出了未来需要重点关注的几个方面: 1)全球变化背景下, 入侵植物对本地植物菌根真菌的影响如何变化; 2)包括这种菌根机制在内的多种入侵机制之间的关系; 3)深入探究入侵的这种菌根机制在大的时空尺度上的变化规律。  相似文献   

11.
菌根真菌共生是植物吸收养分的一个重要策略。外来植物可以干扰本地植物与菌根真菌的共生关系从而抑制本地植物生长, 这是近年来被发现的一种重要入侵机制, 在研究中得到日益广泛的关注。该文从以下几个方面着重综述这种入侵机制: 1)外来植物对本地植物菌根真菌的影响, 包括菌根真菌侵染率、菌根内部结构、根外菌丝的量、菌根真菌的群落组成、非菌根真菌的影响及网络结构; 2)外来植物对本地植物菌根真菌上述影响的机制, 包括资源竞争、化感作用和土壤肥力等生态机制以及相关的分子机制; 3)上述两个方面随入侵时间的变化格局。尽管干扰本地植物菌根真菌是一种重要的入侵机制, 但相对其他的入侵机制(例如天敌逃逸、新武器假说等)来说, 这类机制的研究目前仍很匮乏。鉴于此, 该文提出了未来需要重点关注的几个方面: 1)全球变化背景下, 入侵植物对本地植物菌根真菌的影响如何变化; 2)包括这种菌根机制在内的多种入侵机制之间的关系; 3)深入探究入侵的这种菌根机制在大的时空尺度上的变化规律。  相似文献   

12.
Domestic livestock in Nepal belong to 17 species, including five Bovidae (and interspecific hybrids of two of them), seven Aves, two Equidae (not including mules), pig (Sus scrofa), rabbit (Oryctolagus cuniculus) and elephant (Loxodonta africana). Cattle (Bos taurus and Bos indicus) are the most numerous quadruped, followed by goats (Capra hircus), buffalo (Bubalus bubalis) and sheep (Ovis aries). Domestic fowl (Gallus domesticus) are the most common poultry, followed by pigeons (Columba livia) and ducks (Anas platyrhyncos). Government policy is to upgrade and replace local types with improved stock. This policy has had limited success through lack of funding, inconsistent long-term objectives and an inability to pursue programmes in traditional farming systems. The purity of native types is being lost in some areas due to informal programmes by farmers themselves. Except for one type of goat there are no conservation programmes for native breeds. Wild relatives of livestock, including arnee (Bubalus arnee), gaur (Bibos gaurus), wild boar (Sus scrofa), jungle fowl (Gallus gallus) and rock dove (Columba livia), are being infiltrated by genes of domestic animals. Little has been done to characterize Nepal's livestock resources yet continuous attempts have been made to replace them. Conservation needs are to: (i) identify all genetic resources comprising the gene pool of species used as domestic livestock; (ii) develop and use the associated diversity to increase production, achieve sustainable systems and meet demands for particular products; (iii) monitor resources represented by small numbers or that are being displaced; and (iv) preserve resources not in current demand. A start has been made on this by Nepal's membership of a regional network.  相似文献   

13.
It has been almost 15 years since concerns about the limited capacity of remnant native vegetation to supply the volumes of seed required to meet increasing restoration demands were first raised. Since that time little progress has been made towards addressing this constraint with the ongoing decline of native vegetation communities, especially since 2000, further challenging seed supply. We provide examples of the size of this demand for seed, as well as major issues associated with seed sourcing. We also discuss how invoking the concept of market forces to drive seed supply and demand is inappropriate and highlight the need for an industry body to oversee seed collection and utilisation standards. We further propose key actions that are required to secure the seed supply chain within the next 20 years to meet existing and future restoration targets. We argue that concerted, coordinated action at Commonwealth, State and regional levels are required to underpin effective future restoration outcomes.  相似文献   

14.
对贵州省毕节地区端午节的传统药市进行了初步的民族植物学调查。毕节地区的端午药市出售药物种类繁多,经过2008年至2012年5次的调查,共记录了250多种植物药,其中鉴定整理的药用植物有131种,隶属于55科121属;此文对131种药用植物进行了编目,包括名称、药用部位、用途和用法。此外,还对毕节地区端午药市的可持续发展提出了建议。  相似文献   

15.
Many renaturation projects and compensation areas are based on the use of seeds from regional indigenous wild plants; in the following: native or regional seeds. Despite this, such seeds make up only a small proportion of the total number of seeds used for greening projects; in Germany, for example, it is only around 1% (=200 t per year). Although the market for regional seeds is small, it is highly competitive. High‐priced native seeds compete with flower mixes of unspecified origin and can only be differentiated from them by reliable quality seals. A quality assurance system based on seed legislation (EU Directive 2010/60, preservation mixtures) has been developed in a few European countries. However, quality assurance ends with the sale of the seeds. Thus, seed use remains unmonitored, and often unsuitable material, or material foreign to the region, is planted in restoration areas. Unfortunately, nature conservation has not made seed‐based restoration one of its key issues, neither at the European nor at the national level. Currently there are many different local and regional standards, methods and private certificates that are confusing for users and which provide little continuity and predictability for producers. We recommend the establishment of an EU directive or a broadly agreed recommendation to the EU member states, spearheaded by nature conservation, which would define the standards for producing and using native seeds (e.g. harmonised regions that cross national borders, quality regulations). At the same time, wild plant interest groups should combine existing structures in order to strengthen seed‐based restoration through international cooperation.  相似文献   

16.
We investigated the use of plants collected in the wild by a small farming community in Central Panama to document the importance of noncultivated plants by tropical, nonforest-dwelling, nonindigenous people. We visited the community to observe what wood was used to build houses and interviewed local people about medicinal and edible plants collected in the wild state. The community reported use of 119 noncultivated plant species, including 108 tree species, three shrubs, two herbs, four lianas, and two vines. The majority (71) of the species were used for building homes. Other products built with wood collected in the wild were diverse kinds of tools, containers, cages, and fences. The second most important use of wild plants, in terms of number of species, was firewood, for which 40 species were mentioned by the community. Other uses included fruit for human consumption (20 species). Most of the species (82 of 119) were collected in secondary forests near the community, whereas another large group (47 species) were collected in mature forest. Fewer species were harvested in shrubby regrowth or from isolated trees in farm land. Nearly all the species (111 of 119) were native to the area, and never cultivated locally, but 15 species were considered especially valuable, and were often protected when found as juveniles. Only six of the species are commonly used in reforestation programs in Panama. We conclude that even hispanic communities in tropical Latin America, living outside the forest, with no Amerindian inhabitants, make frequent use of the great diversity of trees native to the region.  相似文献   

17.
理解入侵生物的繁殖策略是阐明生物入侵机制的一个重要方面。入侵植物常表现出一些共同的繁殖特征, 如以两性花为主的性系统、自动自交为主的繁育系统或不依赖传粉媒介的无融合生殖和无性繁殖以及高生殖投资的资源配置策略等。成功入侵的外来植物通过影响本土的传粉者, 在种群和群落水平上影响本土植物的有性繁殖, 甚至促使某些本土植物在繁殖对策和表型性状上发生快速转变。目前, 入侵植物繁殖策略及其生态效应的研究多侧重于入侵种的快速演化, 而有关外来植物与本土植物间的相互影响及其可能存在的协同适应研究还较为缺乏。探讨本土植物在外来种入侵压力下的繁殖对策和响应机制, 将丰富人们对物种间竞争、共存及群落构建等机制的深入了解。从繁殖和适应的角度探求入侵植物与本土植物之间的复杂关系, 将有助于解析生物入侵的机制及人类干扰下的物种演化规律, 也为预测和防控入侵植物提供科学依据。  相似文献   

18.
19.
Native plant materials (NPMs) are increasingly utilized during the restoration of disturbed plant communities. Here, we analyze next‐generation genetic sequencing data for Hilaria jamesii, a dominant graminoid across drylands of the southwestern United States, and document that the species' only commercially‐available NPM, “Viva,” is a hybrid between H. jamesii and its sister species, Hilaria mutica. In fact, hybrids between these species are common where they geographically overlap. Furthermore, we show that the “Viva” hybrid has successfully been moved beyond the hybrid zone and into the core range of H. jamesii. The potential ramifications of introducing novel genetic material into H. jamesii are discussed, as well as the utility of genetic analyses to protect species' natural patterns of genetic diversity and help managers make informed decisions regarding the development and deployment of NPMs.  相似文献   

20.
柳晓燕  朱金方  李飞飞  赵彩云 《生态学报》2021,41(24):9613-9620
为探究外来入侵植物豚草(Ambrosia artemisiifolia)对本地植物群落结构的影响,结合区内林下草本植物调查和室内分析方法,分析了豚草不同入侵压力下(无入侵、轻度入侵、中度入侵、重度入侵)本地草本植物丰富度、盖度等特征,探讨了地形、气候、土壤、光照、人口密度等外部因素与豚草种群特征、本地植物群落结构之间的关系。结果表明:豚草种群盖度与其高度、密度、生物量显著正相关。与对照相比,轻度入侵下本土草本植物Shannon-Wiener多样性指数和Pielou均匀度指数显著增加,丰富度、盖度未出现显著差异。随着豚草入侵程度加剧,本地草本植物物种丰富度、盖度极显著降低,样方Shannon-Wiener多样性指数先升高再降低,本土草本植物Pielou均匀度指数差异不显著。冗余分析(RDA)表明,土壤全氮、与道路距离、土壤全磷、郁闭度对研究区植物群落结构影响最大,土壤全氮含量随豚草盖度和生物量增加而减少,距道路越近或光照越强,豚草盖度和生物量越高。增强伊犁河谷地区交通往来货物豚草检验检疫力度、增加林内植被郁闭度或是抑制区内豚草入侵的有效手段。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号