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91.
JACLYN M. HALL NEIL D. BURGESS SALLA RANTALA HEINI VIHEMÄKI GEORGE JAMBIYA ROY E. GEREAU FORTUNATUS MAKONDA FADHILI NJILIMA PETER SUMBI ADAM KIZAJI 《Conservation biology》2014,28(6):1512-1521
Balancing ecological and social outcomes of conservation actions is recognized in global conservation policy but is challenging in practice. Compensation to land owners or users for foregone assets has been proposed by economists as an efficient way to mitigate negative social impacts of human displacement from protected areas. Joint empirical assessments of the conservation and social impacts of protected area establishment involving compensation payments are scarce. We synthesized social and biological studies related to the establishment of the Derema forest corridor in Tanzania's biodiverse East Usambara Mountains. This lengthy conservation process involved the appropriation of approximately 960 ha of native canopy agroforest and steep slopes for the corridor and monetary compensation to more than 1100 claimants in the surrounding villages. The overarching goals from the outset were to conserve ecological processes while doing no harm to the local communities. We evaluated whether these goals were achieved by analyzing 3 indicators of success: enhancement of forest connectivity, improvement of forest condition, and mitigation of negative impacts on local people's livelihoods. Indicators of forest connectivity and conditions were enhanced through reductions of forest loss and exotic species and increases in native species and canopy closure. Despite great efforts by national and international organizations, the intervention failed to mitigate livelihood losses especially among the poorest people. The Derema case illustrates the challenges of designing and implementing compensation schemes for conservation‐related displacement of people. Resultados Ecológicos y Sociales de un Área Protegida Nueva en Tanzania 相似文献
92.
Repeated cutting of vegetation at or near ground level in power-line corridors is a common practice for inhibiting tree growth
and regeneration. However, few data exist on long-term community responses. In this study, we sampled 20 northern Kentucky
power-line corridors and compared their seedling and sapling communities to the edges and interiors of adjacent undisturbed
forests. Mean seedling and sapling density in corridors was roughly twice that of adjacent undisturbed forest interiors, suggesting
that repeated cutting is not a viable method of inhibiting tree regeneration. Corridor communities were dominated byRobinia pseudoacacia (black locust) andFraxinus americana (white ash), but ordinations indicated strong similaritties among communities in corridors and adjacent forests. Many of
the tree species found in adjacent forests, with the exception of a few shade-tolerant species, had highest seedling and sapling
densities in corridors. Stump or root sprouting by many species appears to regenerate forests quickly after cutting. However,
disturbed soil and detritus accumulations caused by management crews and their equipment may also create a large variety of
microsites for seedling establishment. Because repeated cutting selects for dominance by species with highest sprout growth
rates, it should not be used as the sole management technique. It may instead be used to alter the vigor, stature, and stored
reserves of trees so that herbicides or other methods of tree control can be used more efficiently. 相似文献
93.
讨论了自然遗产的概念,通过对自然遗产概念的讨论进一步分析了自然遗产的特征并对自然遗产进行了分类,最后对自然遗产与文化遗产、自然遗产与地质遗迹进行了辨析 相似文献
94.
Jud Harvey Jesus Gomez‐Velez Noah Schmadel Durelle Scott Elizabeth Boyer Richard Alexander Ken Eng Heather Golden Albert Kettner Chris Konrad Richard Moore Jim Pizzuto Greg Schwarz Chris Soulsby Jay Choi 《Journal of the American Water Resources Association》2019,55(2):369-381
Downstream flow in rivers is repeatedly delayed by hydrologic exchange with off‐channel storage zones where biogeochemical processing occurs. We present a dimensionless metric that quantifies river connectivity as the balance between downstream flow and the exchange of water with the bed, banks, and floodplains. The degree of connectivity directly influences downstream water quality — too little connectivity limits the amount of river water exchanged and leads to biogeochemically inactive water storage, while too much connectivity limits the contact time with sediments for reactions to proceed. Using a metric of reaction significance based on river connectivity, we provide evidence that intermediate levels of connectivity, rather than the highest or lowest levels, are the most efficient in removing nitrogen from Northeastern United States’ rivers. Intermediate connectivity balances the frequency, residence time, and contact volume with reactive sediments, which can maximize the reactive processing of dissolved contaminants and the protection of downstream water quality. Our simulations suggest denitrification dominantly occurs in riverbed hyporheic zones of streams and small rivers, whereas vertical turbulent mixing in contact with sediments dominates in mid‐size to large rivers. The metrics of connectivity and reaction significance presented here can facilitate scientifically based prioritizations of river management strategies to protect the values and functions of river corridors. 相似文献
95.
丝绸之路运输通道风险测算可有效分析通道风险因素,为国际运输宏观政策制定及风险管控提供理论支撑。针对25个国家的7条运输通道,结合文献分析法获取国家运输节点风险的影响因素,利用因子分析法量化综合风险;基于运输通道风险构成机制结合多维度的不均衡指数构建国家运输支撑力下的运输通道风险测度模型。结果表明:北线和西1通道风险最小,南线通道风险最大;运输通道风险测度受国家数目、国家参与程度及其影响力及国家风险状态影响;各运输通道内部与通道间均存在风险不均衡现象。 相似文献
96.
Many studies have evaluated effectiveness of corridors by measuring species presence in and movement through small structural corridors. However, few studies have assessed whether these response variables are adequate for assessing whether the conservation goals of the corridors have been achieved or considered the costs or lag times involved in measuring the response variables. We examined 4 response variables—presence of the focal species in the corridor, interpatch movement via the corridor, gene flow, and patch occupancy—with respect to 3 criteria—relevance to conservation goals, lag time (fewest generations at which a positive response to the corridor might be evident with a particular variable), and the cost of a study when applying a particular variable. The presence variable had the least relevance to conservation goals, no lag time advantage compared with interpatch movement, and only a moderate cost advantage over interpatch movement or gene flow. Movement of individual animals between patches was the most appropriate response variable for a corridor intended to provide seasonal migration, but it was not an appropriate response variable for corridor dwellers, and for passage species it was only moderately relevant to the goals of gene flow, demographic rescue, and recolonization. Response variables related to gene flow provided a good trade‐off among cost, relevance to conservation goals, and lag time. Nonetheless, the lag time of 10–20 generations means that evaluation of conservation corridors cannot occur until a few decades after a corridor has been established. Response variables related to occupancy were most relevant to conservation goals, but the lag time and costs to detect corridor effects on occupancy were much greater than the lag time and costs to detect corridor effects on gene flow. Variables de Respuesta para la Evaluación de la Efectividad de los Corredores de Conservación 相似文献
97.
耕地整理的景观效应分析 总被引:13,自引:0,他引:13
论文通过对不同耕地类型区的典型样区调查获得的小尺度耕地景观现状特征与各耕地类型在不同整理水平下的耕地景观细部规划设计下的景观特征进行对比分析来研究北京市延庆县耕地整理的景观效应。选用斑块平均面积、平均周长、密度、边界密度、平均斑块周长面积比等指标来描述整理前后耕地景观斑块特征的变化;采用廊道类型、廊道占耕地景观面积的比例、各类型廊道占总廊道长度的比例、密度、网络连通度、网络环通度等来表达整理前后廊道特征的变化。研究结果表明,通过耕地整理明显提高了斑块平均面积、平均周长,降低了斑块密度、边界密度、平均斑块周长面积比,提高了景观粒度,减小了耕地景观破碎化程度和耕地景观被边界分割程度。整理后廊道占耕地景观面积比例减小;整理后耕地廊道系统中各廊道类型占总廊道长度的比例趋于合理;廊道类型中增加了农田防护林带,改变了耕地内单一类型景观格局;提高了道路、沟渠等廊道的网络连通度和环通度,有利于农田生态系统中物质和能量流动。 相似文献
98.
陕西省近几年谋求转型发展,致力于将旅游业转换成为陕西省新兴支柱产业,并使其成为陕西转型升级的突破口,进而打造文化旅游大省.陕西省非物质文化遗产旅游资源丰富,在竞争中独具优势,市场前景广阔.因旅游开发起步晚,关注度低,存在着一定程度的欠缺.文章通过研究陕西省非物质文化遗产旅游资源的空间分布,同时采用网络文本分析法分析游客感知,认为应更多的关注游客认知与反馈,提高游客认同感,从而提出陕西省非物质文化遗产旅游的开发模式. 相似文献
99.
100.