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1.
The Houses That Matsutake Built. In the mountains of northwest Yunnan, China, a valuable mushroom, matsutake or song rong (Tricholoma matsutake) was commodified in the 1980s. Since that time, it has been exported in large quantities to Japan. The sale of matsutake now contributes more to the income of Shangri-la County (Diqing Autonomous Tibetan Prefecture) than any other crop, including timber and livestock. During the 1980s and 1990s, villagers in this remote region used their mushroom earnings to build spacious, beautiful new houses in the traditional local (Kham) style, and in some cases to buy motor vehicles or open businesses. In villages with access to productive matsutake habitat, virtually every household was able to build a new house; entire villages were transformed. During the 1990s, several villages developed locally based management regimes to enhance production and to address the problems and conflicts that arose from the harvest of such a valuable product. More recently, government agencies and NGOs have played a highly visible role in promoting “sustainable” harvest policies. The implications of their involvement are briefly examined and the future of matsutake harvest in Yunnan is discussed.  相似文献   

2.
Changes in land use strongly influence habitat attributes (e.g., herbaceous ground cover and tree richness) and can consequently affect ecological functions. Most studies have focused on the response of these ecological functions to land‐use changes within only a single vegetation type. These studies have often focused solely on agricultural conversion of forests, making it nearly impossible to draw general conclusions across other vegetation types or with other land‐use changes (e.g., afforestation). We examined the consequences of agricultural conversion for seed removal by ants in native grassland, savanna, and savanna‐forest habitats that had been transformed to planted pastures (Brachiaria decumbens) and tree plantations (Eucalyptus spp.) and explored if changes in seed removal were correlated with differences in habitat attributes between habitat types. We found that land‐use changes affected seed removal across the tree cover gradient and that the magnitude of impact was influenced by similarity in habitat attributes between native and converted habitats, being greater where there was afforestation (Eucalyptus spp in grassland and savanna). Herbaceous ground cover, soil hardness, and tree richness were the most important habitat attributes that correlated with differences in seed removal. Our results reveal that the magnitude of impact of land‐use changes on seed removal varies depending on native vegetation type and is associated with the type of habitat attribute change. Our findings have implications for biodiversity in tropical grassy systems: afforestation can have a greater detrimental impact on ecological function than tree loss.  相似文献   

3.
California Porcini: Three New Taxa, Observations on their Harvest, and the Tragedy of No Commons. Seven species of California porcini (Boletus, sect. Boletus) are recognized, including three new taxa that are culturally and economically significant: B. rex-veris sp. nov., B. regineus sp. nov., and B. edulis var. grandedulis var. nov. The three new taxa have been intensively gathered during the last century by Italian immigrants, and B. rex-veris sp. nov. more recently by southeast Asian immigrants as well as by long-time rural residents. B. rex-veris sp. nov. is restricted to inland mountains while the other two are widely distributed, and are abundant in California’s heavily populated coastal zone. In the 1990s, reflecting the preservationist policies of mainstream environmental organizations, many park authorities and land management agencies in coastal California closed public lands to mushroom gathering. Organized attempts to establish legal, limited gathering in a few parks were almost entirely unsuccessful. The result is that it is illegal to pick porcini on nearly all public lands over a 6,000-square-mile area, even though they grow prolifically in coastal California. Many of coastal California’s porcini are picked anyway by those willing to risk being apprehended and fined. In response to the official intolerance for mushroom gathering, an entire generation of mushroom hunters has grown up practicing the activity in secret.  相似文献   

4.
Habitat protection is a major component of the Exxon Valdez oil spill restoration process. The acquisition of private lands, or partial interests in private lands, is intended to promote natural recovery of spill-injured resources and services by removing the threat of additional development impacts. The Comprehensive Habitat Protection Process is the method that was designed to achieve this objective. Over one million acres within the oil spill affected area were evaluated, scored, and ranked by a multi-criteria evaluation process. Initially, lands were divided into large parcels encompassing entire bays and watersheds. Criteria were then used to assess the habitat and human-use values associated with each parcel and the protection benefit that acquisition would provide for 19 injured resources and services. This process has been the basis for the acquisition of 41,549 acres of land on Afognak Island and 23,800 acres on the Kenai Peninsula and for agreements that, if consummated, will result in the acquisition of fee or lesser rights on over a half million acres of land in the Kodiak Archipelago, on the Kenai Peninsula, and in Prince William Sound. All of these lands or rights, if acquired, will be incorporated into parks or refuges or otherwise managed in a manner that will facilitate the recovery of the resources and services injured by the oil spill.  相似文献   

5.
Land‐use change is one of the biggest threats to biodiversity globally. The effects of land use on biodiversity manifest primarily at local scales which are not captured by the coarse spatial grain of current global land‐use mapping. Assessments of land‐use impacts on biodiversity across large spatial extents require data at a similar spatial grain to the ecological processes they are assessing. Here, we develop a method for statistically downscaling mapped land‐use data that combines generalized additive modeling and constrained optimization. This method was applied to the 0.5° Land‐use Harmonization data for the year 2005 to produce global 30″ (approx. 1 km2) estimates of five land‐use classes: primary habitat, secondary habitat, cropland, pasture, and urban. The original dataset was partitioned into 61 bio‐realms (unique combinations of biome and biogeographical realm) and downscaled using relationships with fine‐grained climate, land cover, landform, and anthropogenic influence layers. The downscaled land‐use data were validated using the PREDICTS database and the geoWiki global cropland dataset. Application of the new method to all 61 bio‐realms produced global fine‐grained layers from the 2005 time step of the Land‐use Harmonization dataset. Coarse‐scaled proportions of land use estimated from these data compared well with those estimated in the original datasets (mean R2: 0.68 ± 0.19). Validation with the PREDICTS database showed the new downscaled land‐use layers improved discrimination of all five classes at PREDICTS sites (< 0.0001 in all cases). Additional validation of the downscaled cropping layer with the geoWiki layer showed an R2 improvement of 0.12 compared with the Land‐use Harmonization data. The downscaling method presented here produced the first global land‐use dataset at a spatial grain relevant to ecological processes that drive changes in biodiversity over space and time. Integrating these data with biodiversity measures will enable the reporting of land‐use impacts on biodiversity at a finer resolution than previously possible. Furthermore, the general method presented here could be useful to others wishing to downscale similarly constrained coarse‐resolution data for other environmental variables.  相似文献   

6.
吴未  张敏  许丽萍  欧名豪 《生态学报》2015,35(14):4897-4906
生境网络对于物种更具有生态意义。研究土地利用变化对生境网络的影响,对破碎景观中种群的扩散和迁徙至关重要。研究结果有助于区域生境网络的恢复和完善,从物种的角度而非景观结构的角度优化生态网络。以城市化快速发展、土地利用变化明显的苏锡常地区为研究区域,优势湿地鸟类白鹭为代表物种,构建物种生境斑块约束条件概念模型,提出按照物种生活习性特征划分、选择生境斑块的方法,并从斑块和网络结构两个视角分析了土地利用变化对生境网络的影响。结果表明:(1)2000—2010年研究区白鹭生境的适宜地类总面积虽有所增加,但主要由于大量新增线性人为干扰致使白鹭生境网络质量下降;(2)白鹭生境网络在研究区不是全区覆盖的回路,基本由宜兴—溧阳片、无锡滨湖片、苏州吴中片和苏州阳澄湖片4个小片网构成,其完整程度按照宜溧片、滨湖片、吴中片、阳澄湖片降次排列;至2010年,宜溧片破坏最为严重,滨湖片和吴中片次之,阳澄湖片受破坏程度相对最弱。总体上,白鹭生境境况在10年间恶化明显,土地利用变化朝着不利于白鹭持续生存的方向发展。  相似文献   

7.
We analyse the current situation of the Golden eagle (Aquila chrysaetos) in the region of Galicia in NW Spain. At present, the entire Galician population (five pairs) is located within an area of about 2000 km2 in the province of Ourense. To identify high-priority areas for golden eagle conservation, we derived predictive models of habitat suitability using logistic regression and a Geographic Information System (GIS). Specifically, to model the distribution of the breeding population we considered topographic features, land use and degree of humanization, using a 10 × 10 km grid. Presence/absence of golden eagle nests was used as the dependent variable; analyses were performed both considering current nesting areas and considering old nesting areas (1960s and 70s). At the spatial scale considered, the best predictors of habitat suitability for breeding were topographical variables indicative of rugged relief. For current nesting areas the most parsimonious model included maximum altitude. We consider that the predictive models obtained may be of use for the monitoring and conservation management of the golden eagle population in this region. Conservation problems associated with habitat constraints such as food supply, availability of nesting sites, changes in land use and human disturbance are discussed.  相似文献   

8.
Mass production is a logical outcome of price competition in a capitalist economy. It has resulted in the need for large-scale logging and planting of commercial crops. However, such monotonous land use, or monoculture, has damaged various ecological functions of forests and eroded the beneficial public service provided by forests. In Japan, the most widespread monotonous land use is associated with coniferous plantations, the expansion of which was encouraged by Forest Agency policies from 1958 that were aimed at increasing wood production. By 1986, half of all forested lands had been transformed into single-species conifer plantations. These policies may damage the ecological functions of forests: to provide stable habitats for forest wildlife. In particular, food supplies for wildlife have fluctuated greatly after several decades of logging. Some species have therefore changed their ecology and begun to explore novel environments proactively in order to adapt to such extreme fluctuations. Such species have started to use farmlands that neighbor the plantations. In this sense, crop raiding by wildlife can be regarded as a negative result of monotonous land use due to the loss of ecological functions. Therefore, habitat management to rehabilitate ecological functions and to reorganize the landscape will be required in order to resolve the problem of crop raiding by wildlife. This study examines crop raiding by Japanese deer (Cervus nippon) and monkeys (Macaca fuscata) on the island of Yakushima, which typifies crop-raiding situations in Japan.  相似文献   

9.
Vegetation surveys were carried out at 24 sampling stations distributed over four land use types, namely near-primary forest, secondary forest, agroforestry systems and annual crop lands in the northeastern part of the Korup region, Cameroon, to assess the impact of forest conversion on trees and understorey plants. Tree species richness decreased significantly with increasing level of habitat modification, being highest and almost equal in secondary and near-primary forests. Understorey plant species richness was significantly higher in annual crop lands than in other land use types. The four land use types differed in tree and understorey plant species composition, the difference being smaller among natural forests. Tree and understorey plant density differed significantly between habitat types. Density was strongly correlated with species richness, both for trees and understorey plants. Five tree and 15 understorey plant species showed significant responses to habitat. A 90% average drop in tree basal area from forest to farmland was registered. Our findings support the view that agroforestry systems with natural shade trees can serve to protect many forest species, but that especially annual crop lands could be redesigned to improve biodiversity conservation in agricultural landscapes of tropical rainforest regions.  相似文献   

10.
Global biodiversity is decreasing rapidly. Parks and protected lands, while designed to conserve wildlife, often cannot provide the habitat protection needed for wide‐ranging animals such as the American black bear (Ursus americanus). Conversely, private lands are often working landscapes (e.g., farming) that have high human footprints relative to protected lands. In southwestern Alberta, road densities are highest on private lands and black bears can be hunted year‐round. On protected lands, road densities are lowest, and hunting is prohibited. On public lands under the jurisdiction of the provincial government (Crown lands), seasonal hunting is permitted. Population estimates are needed to calculate sustainable harvest levels and to monitor population trends. In our study area, there has never been a robust estimate of black bear density and spatial drivers of black bear density are poorly understood. We used non‐invasive genetic sampling and indices of habitat productivity and human disturbance to estimate density and abundance for male and female black bears in 2013 and 2014 using two methods: spatially explicit capture–recapture (SECR) and resource‐selection functions (RSF). Land tenure best explained spatial variation in black bear density. Black bear densities for females and males were highest on parkland and lowest on Crown lands. Sex ratios were female‐biased on private lands, likely a result of lower harvests and movement of females out of areas with high male density. Synthesis and application: Both SECR and RSF methods clearly indicate spatial structuring of black bear density, with a strong influence based on how lands are managed. Land tenure influences the distribution of available foods and risk from humans. We emphasize the need for improved harvest reporting, particularly for non‐licensed hunting on private land, to estimate the extent of black bear harvest mortality.  相似文献   

11.
12.
A better understanding of common property resource management systems and institutions is important for conservation and development, as fortress-based approaches towards conservation are increasingly questioned. This paper examines how an indigenous resource management system has operated and supported the protection of an Afro-alpine area in the Central Highlands of Ethiopia. The community was mainly concerned to regulate their own use of natural resources, including collection of firewood and thatch, and grazing by livestock. The original common property resource management system operated under a previously undescribed indigenous institution known as the Qero system, which was enforced through sanctions and punishments imposed by the community. The Qero system was suspended following the Agrarian Reform in 1975, which resulted in the breakdown of the traditional land tenure and land rights systems within Ethiopia. In the Central Highlands, user rights and management responsibility shifted to include formerly marginalized groups. Nevertheless, the common property management system has shown sufficient resilience to withstand these changes and pressures, and is still functioning with defined user groups and byelaws to regulate resource use and manage the area. Nevertheless, attitudes to current and future management are polarized between former and present managers of the common property regime.  相似文献   

13.
We examined the patterns of habitat use of six radio-tagged booted eagles (Hieraaetus pennatus) in a Special Protection Area (SPA) in southeastern Spain. Variable percentages of radio locations (20.8–72.0 %) and home range areas (45.2–81.3 %) lay outside the SPA limits. A model selection procedure showed that habitat use was mainly influenced by habitat type and the distance to the nest. Edges and open lands were the most selected habitat types at long distances, while the probability of forest use strongly decreased with the distance. We conclude that effective conservation strategies for this species should encourage not only the protection of the forest nesting habitats, but also the traditional agricultural practices of the surrounding agroecosystems.  相似文献   

14.
Curcuma zedoaria (Christm.) Roscoe, a member of the family Zingiberaceae, is one of the most widely distributed Curcuma species in Bangladesh. It is a well-known and important species because of its medicinal and horticultural values. However, some plant populations are predicted to be depleted due to habitat destruction and due to extensive collection by local inhabitants. In order to estimate the level of genetic diversity within and between natural populations, RAPD analyses were performed using individual plants from different populations. We used Shannon’s index to partition genetic diversity which clearly demonstrated that hilly populations of Srimangal, Chittagong and Sitakundu maintain rather higher genetic diversity than that of plain land and plateau land populations of Savar and Birganj, respectively. We found a high intrapopulational (Hpop/Hsp) genetic diversity of 0.717 that was higher than the interpopulation diversity G ST[(HspHpop)/Hsp] value of 0.283. Principal Coordinates Analysis (PCoA) showed that individuals of the hilly populations were combined in one group, separated from the plain land and plateau land populations. From a conservation point of view, our results suggest that special attention should be kept on the small populations of plain and plateau lands that are critically threatened due to high anthropogenic activities.  相似文献   

15.
The demand for wood from short rotation coppice (SRC) plantations as a renewable energy source is currently increasing and could affect biodiversity in agricultural areas. The objective was to evaluate the contribution of SRC plantations to phytodiversity in agricultural landscapes assessed as species richness, species–area relationships, Shannon indices, detrended correspondence analysis on species composition, Sørensen similarities, habitat preference proportions, and species proportions found in only one land use. Vegetation surveys were conducted on 12 willow (Salix spp.) and three poplar (Populus spp.) coppice sites as well as on surrounding arable lands, grasslands and forests in central Sweden and northern Germany. SRC plantations were richer in plant species (mean: 30 species per 100 m²) than arable land (10), coniferous forests (13) and mixed forests in Germany (12). Comparing SRC plantations with other land uses, we found lowest similarities in species composition with arable lands, coniferous forests and German mixed forests and highest similarities with marginal grassland strips, grasslands and Swedish mixed forests. Similarity depended on the SRC tree cover: at increased tree cover, SRC plantations became less similar to grasslands but more similar to forests. The SRC plantations were composed of a mixture of grassland (33%), ruderal (24%) and woodland (15%) species. Species abundance in SRC plantations was more heterogeneous than in arable lands. We conclude that SRC plantations form novel habitats leading to different plant species composition compared to conventional land uses. Their landscape‐scale value for phytodiversity changes depending on harvest cycles and over time. As a structural landscape element, SRC plantations contribute positively to phytodiversity in rural areas, especially in land use mosaics where these plantations are admixed to other land uses with dissimilar plant species composition such as arable land, coniferous forest and, at the German sites, also mixed forest.  相似文献   

16.
The butterfly Euphydryas aurinia occurs as a classical metapopulation in Yanjiaping village, Heibei province, China. In the patch network under study there were 38 habitat patches. Most patches were uncultivated, consisting of meadows and fallows, while others had been cultivated, i.e., used as small croplands. In the cultivated patches, the habitat for the butterfly can be classified into two types: meadow type (MTH) and cropland type (CTH). In contrast, the uncultivated habitat patches consists only of MTH. We examined the habitat utilization of ovipositing females and larvae of E. aurinia to assess the effect of mixed land use on the butterfly’s occurrence. More egg clusters and pre-hibernating larval groups were distributed throughout CTH than MTH. This dependence on CTH may be due to the preference of egg-laying females for large-sized host plants, which were mainly concentrated in CTH. Compared to the MTH, the mortality rate in CTH was lower. Therefore, for both eggs and pre-hibernating larvae, the quality of CTH was higher than that of MTH. The conditions in MTH, on the other hand, were important for the development of post-hibernation larvae. A combination of extensive farming and animal husbandry has created a mosaic of meadows and croplands in the habitats studied here, which is typical of rural areas in some developing countries. This study implies that patchy land use typical of traditional agriculture facilitates the long-term persistence of E. aurinia.  相似文献   

17.
李志鹏  张心怡  王苗苗  陈宏  赵健 《生态学报》2023,43(3):1276-1285
预测入侵生物的潜在地理分布、快速评估其高脆弱性区域是实现入侵生物前瞻性风险预警的重要手段。MaxEnt生态位模型是目前应用最广泛的生境风险评估方法,操作简单,预测精度较高,但模型对数据的质量和数量过分依赖。以烟粉虱Bemisia tabaci为对象,引入地理探测器显式描述评价因子的空间关联规律和贡献度,结合MaxEnt生态位模型,提出一种混合生境风险评估模型(Geo-MaxEnt),并与单一MaxEnt生态位模型进行对比。结果表明:(1)地理探测器模型显示,海拔(0.56)、土地利用(0.43)、最热月最高温度(0.36)和年平均温度(0.30),对烟粉虱的空间分布具有显著影响,各因子对烟粉虱生境的影响存在显著的差异。海拔和土地利用PD值最高,是影响烟粉虱生境的主要驱动因子。环境因子的交互作用强化了各个因子的影响力。(2)单一MaxEnt生态位和所构建的模型总体精度分别是94.86%(AUC 0.91)和98.13%(AUC 0.94),相较之下,所构建的模型精度略高,表明所构建的模型是合理的,具有高度的可靠性;(3)对于高风险区,混合模型优于MaxEnt模型,但两者在空间分布方面高度...  相似文献   

18.
Ixodes loricatus has long been considered with strict-total specificity to New World Marsupials. However, frequent findings of its immature stages on rodents suggest that these vertebrates play an important role in the tick’s life cycle. Aspects dealing with the ecology of Sigmodontinae rodents infestation by I. loricatus are unknown. To contribute to the knowledge of the ecology of this tick species, environmental factors, as well as host species, sex and age, were evaluated to find associations of immature I. loricatus infestation of the most abundant wild rodent species from riparian locations of Buenos Aires province (Argentina). A total of 290 hosts belonging to the subfamily Sigmodontinae were captured and examined for ticks at six locations. The data analysis showed that there was a preference of I. loricatus towards Akodon azarae, but only for those hosts captured in lands not prone to flooding. The results suggest that the host preference of I. loricatus is mainly related to factors such as habitat type and host density.  相似文献   

19.
The Key Largo woodrat (Neotoma floridana smalli) and Key Largo cotton mouse (Peromyscus gossypinus allapaticola) are federally endangered subspecies endemic to the tropical hardwood hammocks of Key Largo, Florida. Woodrats are considered generalists in habitat and diet, yet a steady decline in natural stick nests and capture rates over the past several decades suggests that they are limited by the availability of nesting habitat due to habitat loss and fragmentation. The more specialized Key Largo cotton mouse appears to rely on old growth hammock, a habitat type that is rare following past land clearing. In 2004, the U.S. Fish and Wildlife Service started building supplemental nest structures to restore habitat quality and connectivity for these endangered rodents, but nest use requires evaluation. We used camera traps and occupancy models to evaluate the factors influencing woodrat and cotton mouse use of the supplemental nests. We detected woodrats at 65 and cotton mice at 175 of 284 sampled nest structures, with co‐occurrence at 38 nests. Woodrat nest use followed a gradient from low nest use in the north to high nest use in the south, which might relate to the proximity of free‐ranging domestic cat (Felis catus) colonies in residential developments. Cotton mouse nest use, however, was related positively to mature hammock and related negatively to disturbed areas (e.g. scarified lands). The two species occurred independently of each other. Stick‐stacking behavior was observed at supplemental nests and, although it was correlated with detection of woodrats, it was not a strong predictor of their occurrence. We suggest that nest supplementation can be an important tool for species recovery as habitat quality continues to improve with succession.  相似文献   

20.
ABSTRACT The Farm Bill conservation programs serve as the primary tools for the creation and improvement of wildlife habitat on working lands. Wildlife conservation would benefit from a working land-prioritization system that integrates these programs. We developed a Geographic Information System (GIS)–based system to prioritize land for inclusion in Farm Bill conservation programs. We designed the system to be applicable throughout the United States, to minimize potential conflicts of interest, and to facilitate simple implementation. We designated high conservation value (HCV) lands using habitats of greatest conservation need. We placed priority zones around HCV lands to determine high- and low-priority working lands. Nationwide implementation of this system would require gathering and manipulating data from multiple sources, as well as creation of a GIS layer denoting locations of working lands currently in conservation programs. This system would allow funding to be maximized through the ability to select participation based on property location and size, and to target landowners for participation. The wide-ranging potential benefits of this system make it well-suited for serving as the backbone to conservation on working lands.  相似文献   

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