自然生态小区建设指导原则及其建设内容探讨--以筠连县大雪山自然生态小区为例

自然生态小区是构建优美生态环境区域的生态“细胞工程”。它根据当地的自然状况和社会经济状况,以较小的经济和社会代价实现一定区域生态环境优美、生态文明有序、生态系统良性循环的社会经济生态综合体。由于自然生态小区的建设是新兴事物,其建设途径还有很多问题值得探讨。在自然生态小区建设投资方面,应当明确生态环境建设投资和生产赢利建设投资,对于前者应当以政府和政策性投资为主,而后者应当是在政策法规规范下的企业投资为主;在发展模式方面,应当促进环境友好的规模化高效益产业,包括有机绿色产业、地方特色产业、民族文化产业等;在效益分配方面,必须要充分考虑整个社区居民资源共享和利益合理分配,实现整个社区生态文明建设和经济发展目标的一致。     

Trait space of rare plants in a fire‐dependent ecosystem

The causes of species rarity are of critical concern because of the high extinction risk associated with rarity. Studies examining individual rare species have limited generality, whereas trait‐based approaches offer a means to identify functional causes of rarity that can be applied to communities with disparate species pools. Differences in functional traits between rare and common species may be indicative of the functional causes of species rarity and may therefore be useful in crafting species conservation strategies. However, there is a conspicuous lack of studies comparing the functional traits of rare species and co‐occurring common species. We measured 18 important functional traits for 19 rare and 134 common understory plant species from North Carolina's Sandhills region and compared their trait distributions to determine whether there are significant functional differences that may explain species rarity. Flowering, fire, and tissue‐chemistry traits differed significantly between rare and common, co‐occurring species. Differences in specific traits suggest that fire suppression has driven rarity in this system and that changes to the timing and severity of prescribed fire may improve conservation success. Our method provides a useful tool to prioritize conservation efforts in other systems based on the likelihood that rare species are functionally capable of persisting.     

Understanding local community attitudes toward industrial development in the Great Barrier Reef region World Heritage Area: are environmental impacts perceived to overshadow economic benefits?

Conflicts between industrial development and environmental conservation can be particularly acute when such development occurs in the vicinity of World Heritage sites. A key example is the Great Barrier Reef World Heritage Area (GBRWHA) in northeastern Australia, where a 2012 review by the World Heritage Council found that rapid port development inshore of the coral reef posed significant risks to local marine ecosystems. Such instances pose pressing challenges for decision‐makers seeking to manage World Heritage sites for multiple values and needs, including those of key stakeholder groups, such as local communities. There is increasingly a societal expectation that public decision‐making takes into account local views and priorities, and that companies seek a ‘social license to operate’. This research explored local community attitudes toward port development associated with the export of liquefied natural gas (LNG) and coal through the GBRWHA. Using data drawn from a survey and interviews, the research examined how a range of geographical factors, including proximity to gas infrastructure and the perceived impacts and risks of development to the local community, economy and environment shape community perceptions of the industry. Findings suggest that local attitudes toward gas and coal terminal development inshore of the GBRWHA are shaped predominantly by community perceptions of environmental impacts and risks associated with such infrastructure, in contrast to a broader public narrative that focuses largely on economic benefits. A complex combination of other factors, including social impacts, personal environmental values, community trust in industry, and equity in decision‐making and distribution of the risks and benefits of industrial development also contribute. Placed in a broader, global context, the findings have important implications for public decision‐making processes in Australia and elsewhere as they suggest that, for local communities, the perceived impacts of gas development on the environment may overshadow the benefits of industry.     

三峡库区消落带水淹初期主要优势草本植物生态位变化特征

根据三峡库区初期水位涨落情况,以空间代替时间法,连续两年对典型消落带区域地上植被进行调查,通过计算生态位宽度和生态位重叠来分析不同水淹时间下优势草本植物生态位的变化特征。结果表明,一年水淹区段在未水淹时,植物生态位宽度普遍较窄,此时生态位明显特化,而第二年水淹极大的增加了适应干湿变化的物种的优势度。水淹前生态位重叠值大于0.5的只有12对,小于0.2种对为189对,其中生态位重叠值为零的为103对;水淹后生态位重叠值大于0.5的有24对,小于0.2种对为53对,其中生态位重叠值为零的为6对,说明生境由干燥到湿润的变化,对湿润环境相对适应的物种存活,优势植物生态位重叠明显增加。经两年水淹区段中,第一年以毛马唐的生态位宽度最高,其余17种物种生态位宽度小于0.2的物种占优势物种的61%,第二年以雾水葛和鳢肠的生态位宽度较大,其余15种物种生态位宽度小于0.2的物种占优势物种的50%,共同出现的物种仅有8种。生态位重叠值大于0.5的种对由5对上升到17对,生态位重叠值为零的种对由10对减低到2对,说明连续水淹产生更加均一的生境类型,对资源要求相似的物种是增加的。     

Trait‐based prediction of extinction risk of small‐bodied freshwater fishes

Small body size is generally correlated with r‐selected life‐history traits, including early maturation, short‐generation times, and rapid growth rates, that result in high population turnover and a reduced risk of extinction. Unlike other classes of vertebrates, however, small freshwater fishes appear to have an equal or greater risk of extinction than large fishes. We explored whether particular traits explain the International Union for Conservation of Nature (IUCN) Red List conservation status of small‐bodied freshwater fishes from 4 temperate river basins: Murray‐Darling, Australia; Danube, Europe; Mississippi‐Missouri, North America; and the Rio Grande, North America. Twenty‐three ecological and life‐history traits were collated for all 171 freshwater fishes of ≤120 mm total length. We used generalized linear mixed‐effects models to assess which combination of the 23 traits best explained whether a species was threatened or not threatened. We used the best models to predict the probability of 29 unclassified species being listed as threatened. With and without controlling for phylogeny at the family level, small body size—among small‐bodied species—was the most influential trait correlated with threatened species listings. The k‐folds cross‐validation demonstrated that body size and a random effect structure that included family predicted the threat status with an accuracy of 78% (SE 0.5). We identified 10 species likely to be threatened that are not listed as such on the IUCN Red List. Small body size is not a trait that provides universal resistance to extinction, particularly for vertebrates inhabiting environments affected by extreme habitat loss and fragmentation. We hypothesize that this is because small‐bodied species have smaller home ranges, lower dispersal capabilities, and heightened ecological specialization relative to larger vertebrates. Trait data and further model development are needed to predict the IUCN conservation status of the over 11,000 unclassified freshwater fishes, especially those under threat from proposed dam construction in the world's most biodiverse river basins.     

How farmers develop local ecological knowledge for on-farm tree management: The perspectives of some farming communities of Ghana

Scientific insights into what it means to manage on-farm trees by local farmers, is an essential step towards documenting local ecological knowledge for sustainable landscape management. A study was therefore conducted in the Kumawu Forest District in the Ashanti Region of Ghana to assess how farmers conceptualise on-farm tree management and develop local knowledge for it. Using a case study approach, data were collected through informal interviews and focus group discussions with 120 farmers drawn from 15 communities who were involved in the management of three cropping systems; cocoa, maize and cassava-cocoyam-plantain mix. It was observed that the farmers regard on-farm tree management as a continuous process which occurs in three phases of the farming cycle; land preparation, crop cultivation and fallow management. For each of the three phases, farmers are guided by specific principles that ensure enough light penetration in-between tree crowns in the land preparation phase, suitable spacing between trees and crops in the crop cultivation phase and adequate tree regeneration in the fallow phase. The decisions made during the selection of tree species, spacing of trees adjudged suitable for any particular cropping system and recruitment of saplings prior to the fallow phase of farming constitute tree management. Farmers develop tree management knowledge by studying the physical characteristics of species, matching them to ecological functions they could perform and how they are likely to respond to treatments meant to control or enhance their development. Species are then subjected to trial and recommended or otherwise.     

Systematic Temporal Patterns in the Relationship Between Housing Development and Forest Bird Biodiversity

As people encroach increasingly on natural areas, one question is how this affects avian biodiversity. The answer to this is partly scale‐dependent. At broad scales, human populations and biodiversity concentrate in the same areas and are positively associated, but at local scales people and biodiversity are negatively associated with biodiversity. We investigated whether there is also a systematic temporal trend in the relationship between bird biodiversity and housing development. We used linear regression to examine associations between forest bird species richness and housing growth in the conterminous United States over 30 years. Our data sources were the North American Breeding Bird Survey and the 2000 decennial U.S. Census. In the 9 largest forested ecoregions, housing density increased continually over time. Across the conterminous United States, the association between bird species richness and housing density was positive for virtually all guilds except ground nesting birds. We found a systematic trajectory of declining bird species richness as housing increased through time. In more recently developed ecoregions, where housing density was still low, the association with bird species richness was neutral or positive. In ecoregions that were developed earlier and where housing density was highest, the association of housing density with bird species richness for most guilds was negative and grew stronger with advancing decades. We propose that in general the relationship between human settlement and biodiversity over time unfolds as a 2‐phase process. The first phase is apparently innocuous; associations are positive due to coincidence of low‐density housing with high biodiversity. The second phase is highly detrimental to biodiversity, and increases in housing density are associated with biodiversity losses. The long‐term effect on biodiversity depends on the final housing density. This general pattern can help unify our understanding of the relationship of human encroachment and biodiversity response. Patrones Sistemáticos Temporales en la Relación entre Desarrollos Urbanos y la Biodiversidad de Aves de Bosque     

Application of environmental risk assessment for strategic decision-making in coastal areas: case studies in China

Environmental risk assessment (ERA) is a powerful technical tool for analyzing potential and extreme adverse environmental impacts, and has found wide application in supporting decision-making processes over the last two decades. However, to date there has been no interrelated application of ERA to support the processes of strategic decision-making (SDM), especially in coastal areas.

In this paper, we attempt to verify the feasibility of the proposed integrated ERA–SDM approach and its methodology by applying it to two case studies (in Xiamen Bay and Luoyuan Bay) of the principal coastal functional zoning (PCFZ, a kind of SDM and similar to the coastal and marine spatial planning in western). The results show that the integrated ERA–SDM approach could integrate ERA into the entire SDM process, directly support the PCFZ, and avoid or mitigate dire environmental risk that can be introduced by SDM processes.     

湖岸缓冲带反硝化作用的研究进展

反硝化作用是湖岸缓冲带去除硝酸盐的重要途径。湖岸缓冲带是联系陆地与湖泊生态系的纽带，不仅为许多动植物提供适宜生境，而且通过反硝化作用能去除地下水中的硝酸盐，提高湖泊水质。概述不同检测反硝化速率的方法，并对比各种方法的优点与缺点。阐述反硝化作用的影响因素：厌氧环境、有机碳、湖岸坡度、缓冲带坡度、pH与温度、硝酸盐浓度。介绍反硝化速率模型的研究开发状况。最后，提出了目前国内外反硝化研究中存在的不足及发展方向。     

Combined Effects of Levels of Protection and Environmental Variables at Different Spatial Resolutions on Fish Assemblages in a Marine Protected Area

Abstract: The links between species–environment relations and species’ responses to protection are unclear, but the objectives of marine protected areas (MPAs) are most likely to be achieved when those relations are known and inform MPA design. The components of a species’ habitat vary with the spatial resolution of the area considered. We characterized areas at two resolutions: 250 m² (transect) and approximately 30,000 m² (seascape). We considered three categories of environmental variables: substrate type, bottom complexity, and depth. We sought to determine at which resolution habitat characteristics were a better predictor of abundance and species composition of fishes and whether the relations with environmental variables at either resolution affected species’ responses to protection. Habitat features accounted for a larger proportion of spatial variation in species composition and abundances than differences in protection status. This spatial variation was explained best by habitat characteristics at the seascape level than at the transect level. Species’ responses to protected areas were specific to particular seascape characteristics, primarily depth, and bottom complexity. Our method may be useful for prioritizing marine areas for protection, designing MPAs, and monitoring their effectiveness. It identified areas that provided natural shelter, areas acting as buffer zones, and areas where fish species were most responsive to protection. The identification of such areas is necessary for cost‐effective establishment and monitoring of MPAs.