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991.
The number of protected areas (PAs) has steadily increased in the past 20 years, but their effectiveness to meet conservation targets is consistently questioned. Most conservation impact evaluations of protected areas assume that formal designations, like that of IUCN categories, reflect site-specific conservation rules, but this is not always true. In this paper we illustrate how conservation rules could be empirically assessed by use of content analysis combined with optimal scaling. This flexible methodology allows us to quantitatively assess strictness levels for use in conservation impact evaluations. The strictness measures could also indicate whether conservation rules are consistently applied in the different IUCN categories thereby providing guidance for future assignment of PAs to the IUCN protected area management categories. We illustrate how policy indicators based on conservation rules could be developed in two contrasting mountain protected area networks in Norway and in British Columbia (BC), including a total of 48 PAs in Norway and 51 in BC. Conservation rules for recreational use, motorized access and resource use were quantitatively assessed, thus providing a measure of how strictly PAs regulate the different human activities. Our results show that the main differences in strictness are between the two countries, followed by the contrast between national parks and provincial parks in BC. Overall, Norway has a more liberal conservation policy than BC and older national parks in BC have a much stricter conservation policy than most of the other PAs in this study. Overarching conservation objectives did not reflect the level of strictness (the conservation rules) that guide the daily management of individual PAs. This applies to both countries. We recommend to empirically investigate site-specific conservation rules to include de facto management of human activities in conservation policy impact evaluations. The methodology is also useful for monitoring downgrading of the protected area status, which is a result of authorizing human activities that are not consistent with conservation objectives.  相似文献   
992.
尹航  赵鸣 《生物信息学》2018,25(12):105-109
水是鲁中低山丘陵地带泉水村落景观的重要组成元素。长期以来,居于此地的人们在特殊的自然、社会环境的影响下,创造了极具北方山区特色的泉水村落“水系统”。通过田野调查、测绘、访谈,探讨泉水村落选址对“水系统”环境基底形成的重要性和以“水系统”为特征的村落环境特征,发掘“水系统”的组成要素,总结“水系统”的宏观结构和微观结构,并将其宏观结构分为2个子循环系统和4个分区。研究发掘了鲁中低山丘陵地带泉水村落景观的潜在规律,为维护泉水村落人居环境系统的稳定和乡土景观的改造提供了依据。  相似文献   
993.
994.
In the coastal semideciduous forest of La Mancha, Veracruz (Mexico), we evaluated the removal of fallen fruits and seeds of different species by the land crab Gecarcinus lateralis under different environmental conditions (age soil of forest stand, topography, and cover). Crabs removed 67 percent of the propagules in the experiments (3106 of a total of 4608), and seeds were removed in greater quantities (61.1%) than fruits (38.9%). Fruits of Maclura tinctoria (Moraceae) and Ehretia tinifolia (Boraginacea) and seeds of E. tinifolia were the most affected species. Crabs removed higher quantities of fruits in old‐soil forest and in the understory than in young‐soil forest and gaps. In experiments with seeds, only for the older forest, the crabs removed more seeds in slopes and peaks than in valleys and in the understory than gaps, whereas in the young‐soil forest, the differences were not significant. Our results suggest that G. lateralis, like Gecarcoidea natalis and Gecarcinus quadratus, is an efficient propagule predator and can exert pressure in the establishment of plant species, but in La Mancha, this also depends on site conditions and identity of the species.  相似文献   
995.
Multivariate dispersions are an effective ecological indicator to evaluate the environmental heterogeneity and human disturbance in global ecological research. To explore the feasibility of the dispersions for assessing water quality status, a dataset of the biofilm-dwelling microbial eukaryote communities was studied in coastal waters of the Yellow Sea, northern China at two numerical resolutions. The community dispersion patterns represented a significant variability in both community structure and species composition in response to environmental heterogeneity. Multivariate approaches revealed that the species composition was the primary contributor to the community dispersion. Mantel analysis showed that the spatial variations in both community structure and species composition were significantly correlated with the changes of the nutrients, pH, dissolved oxygen (DO) and chemical oxygen demand (COD). The dispersion measures at both numerical resolutions were found to be remarkably related to the nutrient ammonium nitrogen and DO. Thus, we suggest that multivariate dispersions of the microbial eukaryote communities may be used as a potential bioindicator of water quality status in marine ecosystems.  相似文献   
996.
目的:利用构建的增强子样序列筛选载体,筛选在大肠杆菌中增强外源蛋白质表达的序列,并利用删除突变体初步鉴定其功能区域。方法:以氯霉素乙酰转移酶(CAT)基因序列与人乳头瘤病毒(HPV)主要衣壳蛋白基因L1的截短序列L11连接作为报告基因,从采集的样品中筛选增强子样序列,通过蛋白质表达来检测其增强活性,并通过构建删除突变体来初步鉴定其功能区域。结果:成功筛选到一条增强子样序列,可使检测载体氯霉素抗体提高11倍,融合蛋白表达水平提高2.26倍,其功能区域主要集中在1~265bp。结论:从收集的样品中成功筛选出一个增强子序列,能提高外源基因在大肠杆菌中的表达。  相似文献   
997.
Recent global commitments to forest and landscape restoration in the tropics call for new management approaches that benefit both biodiversity and livelihoods of forest‐dependent people. The sustainable use of wild forest products is a promising pathway, but requires clarity about harvested species' demography and harvesters' rights. Here, we explored how the exploitation of fruits of the threatened palm Euterpe edulis, a key fruit source for wildlife in Brazil's globally important Atlantic Forest biodiversity hotspot, could trigger local community involvement in restoration. This palm has both non‐destructive (fruit) and destructive (palm heart) culinary uses, each with unique biological and resource‐use conditions. We quantified all demographic stages of this species in multiple agroforests, secondary forests, and protected areas to parameterize demographic projections of palm populations, harvest profitability, and fruit provisioning to wildlife under different management scenarios. Field observations showed a clear depression of adult palm populations in protected areas, likely due to palm heart poaching, and of intermediate size classes in agroforests, probably from weeding by farmers. Field data and demographic models reveal that in this region, agroforests and secondary forests can successfully conserve this species while providing lasting profits for farmers under most scenarios. These findings demonstrate a clear case where local stakeholders both contribute to and benefit from restoration through harvest of wild products and also highlight a potential source of income from regenerating tropical forests.  相似文献   
998.
牛科是哺乳纲中物种数量最多的有蹄类动物类群, 在全球广泛分布, 在陆地生态系统中具有重要的生态功能与作用。我国的牛科动物多样性较高, 据历史文献记载共有33种。然而, 自20世纪中期以来, 我国人口快速扩张, 社会经济高速发展, 对环境改造强度空前, 许多野生牛科动物的种群和栖息地受到了极大的影响。因此, 历史资料记载的物种分布是否依然符合现状, 至今未见系统和全面的评估, 不利于对我国动物资源情况的掌握和保护。为此, 我们系统检索并分析了2008年至今(2020年8月31日)在国内外公开发表的432篇学术论文, 以近年报道的红外相机调查结果为核心, 对28种牛科动物的分布以及15种牛科动物的种群现状进行了初步评估。经整理分析: (1)近年公开发表的研究显示, 中国目前有确凿分布证据的野生牛科动物有28种, 包括16种国家I级和11种国家II级重点保护野生动物, 涉及20个生物多样性优先保护区域。其中, 红鬣羚(Capricornis rubidus)属于中国新记录物种。(2)在省级区划层面, 记录到牛科动物物种数量最多的是西藏(n = 11)和甘肃(n = 11), 其次是新疆(n = 10)、青海(n = 7), 以及四川、内蒙古和云南(均为6种)。(3)分布省域最多的牛科动物是中华鬣羚(Capricornis milneedwardsii, 省区, n = 16), 其次是中华斑羚(Naemorhedus griseus, n = 11)和岩羊(Pseudois nayaur, n = 8)。(4)据历史资料记载, 6种未见分布报道的牛科动物主要分布在西藏、新疆、云南, 分别是阿尔泰盘羊(Ovis ammon)、哈萨克盘羊(O. collium)、大额牛(Bos frontalis)、野水牛(B. arnee)、爪哇野牛(B. javanicus)和缅甸斑羚(Naemorhedus evansi)。(5)中华斑羚、赤斑羚(Naemorhedus baileyi)、中华鬣羚、岩羊、北山羊(Capra sibirica)、野牦牛(Bubalus arnee)在IUCN公布的分布区外有新分布记录, 建议及时修订和更新。本研究首次对中国牛科动物的分布以及种群现状进行了较客观和全面的评价, 为后续调查需要重点关注的物种和区域以及未来的研究提供参考。  相似文献   
999.
Plant hotspot areas are the areas that are very rich in plant species diversity. These areas have a priority for conservation. To highlight the plant diversity for nature conservation purposes a case study in Al Baha region, Saudi Arabia is presented, in which the importance of the natural vegetation and flora of one of the hotspot areas of Saudi Arabia is evaluated through the explanation of its natural plant species. A survey study has been conducted in an area of 167.6 km2, a 97 sample each with 20X20 m were laid out covering the whole ecological zones of the study site. Data of flora, vegetation cover and topography were gathered from each sample site. The study revealed about 319 plant species belonging to 228 genera and 75 families. Two species were found endemic to Saudi Arabia, 14 were endemics to Arabian Peninsula, and five were regional endemics that are only found in East Africa and Arabian Peninsula, while 39 species are rare and endangered.  相似文献   
1000.
Empirical evidence for increases in the reproductive potential (egg output per unit area) of coral reef fish in no-take marine reserves (NTMRs) is sparse. Here, we inferred the development of reproductive potential in two species of protogynous reef fishes, Chlorurus bleekeri (Labridae: Scarinae) and Cephalopholis argus (Epinephelidae), inside and outside of Philippine NTMRs. We estimated key reproductive parameters and applied these to species-specific density and length data from 17 NTMRs (durations of protection 0–11 years) and paired fished sites (controls) in a space-for-time substitution approach. For C. argus, we also used density and length data collected almost annually over 29 years from a NTMR and an adjacent control at Apo Island. The results suggest that C. bleekeri can develop 6.0 times greater reproductive potential in NTMRs than controls after 11 years of protection, equivalent to approximately 582,000 more eggs produced 500 m−2 inside NTMRs. Enhancement of reproductive potential in C. argus was not evident after 11 years in the space-for-time substitution. At Apo Island NTMR, reproductive potential of C. argus increased approximately 6-fold over 29 years but NTMR/control ratios in reproductive potential decreased through time (from 3.2 to 2.4), probably due to spillover of C. argus from the NTMR to the control. C. argus was estimated to produce approximately 113,000 more eggs 500 m−2 inside Apo Island NTMR at the 29th year of protection. Ratios of reproductive potential between NTMR and controls in C. bleekeri and C. argus were often greater than corresponding ratios in density or biomass. The study underscores the importance of species-specific reproductive life history traits that drive variation in the development of larval fish subsidies that originate from NTMRs.  相似文献   
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