Shifts from native to non-indigenous mussels: Enhanced habitat complexity and its effects on faunal assemblages     

《Marine environmental research》2013

Ecosystem engineers such as mussels may affect strongly both the structure of benthic assemblages and the ecosystem functioning. The black-pygmy mussel Limnoperna securis is an invasive species that is spreading along the Galician coast (NW Spain). Its current distribution overlaps with the distribution of the commercial native mussel species Mytilus galloprovincialis, but only in the inner part of two southern Galician rias. Here, we analysed the assemblages associated with clumps of the two mussel species and evaluated if the invasive species increased complexity of habitat. To measure complexity of clumps we used a new method modified from the “chain and tape” method. Results showed that the identity of the mussel influenced macrofaunal assemblages, but not meiofauna. L. securis increased the complexity of clumps, and such complexity explained a high percentage of variability of macrofauna. The shift in dominance from M. galloprovincialis to L. securis may alter habitat structure and complexity, affecting the macrofaunal assemblages with unpredictable consequences on trophic web relations.  相似文献   

Long-term changes in coral assemblages under natural and anthropogenic stress in Jakarta Bay (1920-2005)     

Sancia E.T. van der Meij  Suharsono 《Marine pollution bulletin》2010,60(9):1442-1454

Coral reefs in Jakarta Bay have been subjected to scientific studies since the 1920s. Also from that time on biological collections were made. The reefs in the Jakarta Bay have been under long-term natural and anthropogenic stress. With the biological collections and historical documents the coral species richness in Jakarta Bay around 1920 was reconstructed. New data from this bay and the adjacent offshore Thousand Islands archipelago were obtained during a 2005 research expedition. A comparison of the coral assemblages between 1920 and 2005 reveals a clear decline in species numbers. The most prominent results include the near-shore disappearance of species belonging to the families Acroporidae, Milleporidae, and to a lesser extent Poritidae. The overall coral species composition of the reefs has changed considerably, which is partly reflected in a strong decline in coral species richness. About half the number of species recorded in 1920 was found again in 2005.  相似文献   

Ecosystem service provision: an operational way for marine biodiversity conservation and management     

Cognetti G  Maltagliati F 《Marine pollution bulletin》2010,60(11):1916-1923

Since no extensive conceptual framework has been developed on the issues of ecosystem service (ES) and service provider (SP) in the marine environment, we have made an attempt to apply these to the conservation and management of marine biodiversity. Within this context, an accurate individuation of SPs, namely the biological component of a given ecosystem that supports human activities is fundamental. SPs are the agents responsible for making the ES-based approach operational. The application of these concepts to the marine environment should be based on an model different to the terrestrial one. In the latter, the basic model envisages a matrix of a human-altered landscape with fragments of original biodiversity; conversely, in the marine environment the model provides fragments where human activities are carried out and the matrix is represented by the original biodiversity. We have identified three main classes of ES provision: in natural, disturbed and human-controlled environments. Economic valuation of marine ESs is an essential condition for making conservation strategies financially sustainable, as it may stimulate the perceived need for investing in protection and exploitation of marine resources.  相似文献   

Urban environments as habitats for rare aquatic species: The case of leeches (Euhirudinea, Clitellata) in Warsaw freshwaters     

Pawe? Koperski 《Limnologica》2010,40(3):233-240

Reduced biological diversity in freshwater habitats situated in urban areas has been discussed in numerous studies. Certain municipal areas, however, can help save animal diversity of freshwater invertebrates. In the present study animals were collected or observed alive in 13 freshwater environments localized in Warsaw - the second largest city of Central Europe - in a densely populated, urban building complex close to the city, and also in suburban areas. Leech assemblages in all the environments under observation were numerically dominated by a few common species, but on the whole 19 species were collected or observed. The populations of six rare leech species inhabit both flowing and standing waters in Warsaw. Five of these species are on the Polish Red List of Species and one is strictly protected. The shallow Lake Powsinkowskie is the richest freshwater environment in the studied area in terms of species richness and rarity and also one of the richest lakes in Poland. Taxonomic diversity in the environments under study seems not to be directly related to the size of the water body or the level of degradation but rather to the habitat complexity, especially the diversity of the bottom in littoral zone. Certain freshwater habitats located inside this great urban complex still create good conditions for rare, highly specialized species.  相似文献   

Diversity of arbuscular mycorrhizal fungi in the rhizosphere of Asteriscus maritimus (L.) Less., a representative plant species in arid and saline Mediterranean ecosystems     

《Journal of Arid Environments》2013

Native arbuscular mycorrhizal fungi (AMF) from saline areas could be a critical issue for success in recovering areas affected by salinity, either in natural environments or in agricultural lands. Despite its important role, there is little information on the distribution and abundance of the different mycorrhizal associations in saline environments in European Mediterranean areas. In the present study the community of AMF is investigated in the rhizosphere of a representative plant species adapted to saline Mediterranean areas, Asteriscus maritimus. Samples of the rhizosphere of twenty plants were taken from the most arid region in Europe, Cabo de Gata Natural Park, in two different areas: a dune and a salt marsh. A total of 30 AMF species belonging to three classes, five orders, nine families and 13 genera within the phylum Glomeromycota were found from both sites. In the rhizosphere of the salt marsh spore densities were six times higher than in the dunes, although the diversity was similar in both systems. One new AMF species has been described in the dune and four species could not be unequivocally identified, suggesting possible new species.  相似文献   

Integrating landscape connectivity into the evaluation of ecosystem services for biodiversity conservation and its implications for landscape planning     

《Applied geography (Sevenoaks, England)》2013

This paper examines the integration of landscape connectivity and ecosystem services. It is based on the assumption that if a habitat within a landscape has a more significant role in connecting with other habitats, it would have a higher ecosystem services value for biodiversity conservation. The Shenzhen River watershed, a cross-border region shared by the city of Shenzhen and the Hong Kong Special Administrative Region in China, was used as a case study. An area-based functional connectivity index, known as the possibility of connectivity (PC), was implemented to examine the temporal and spatial dynamics of the value of ecosystem services for biodiversity conservation over the period from 1988 to 2008. To evaluate the effectiveness of the PC index, a comparison was made between the conventional assessment method for ecosystem services and the proposed method. Results suggest that our proposed method can identify significant reduction of ecosystem services that was not only due to the decrease of habitat size, but also caused by the damage of connectivity among habitat patches. Also, it can identify sites which should have a high priority in restoring the ecosystem services for biodiversity conservation. In conclusion, this study provides a way to consider landscape connectivity in the evaluation of ecosystem services which is essential for landscape planning and nature conservation.  相似文献   

Wild things in urban places: America's largest cities and multi-scales of governance for endangered species conservation     

《Applied geography (Sevenoaks, England)》2013

Endangered species live inside the world's most densely populated cities. In the United States, the Fish and Wildlife Service is responsible for the protection and recovery of endangered species – wherever those species are found. Unfortunately, very little is known about urban endangered species policy or programs. This paper presents a comparative analysis of the five largest cities in the United States and examines issue of governance around conservation. Cities have a responsibility to steward the environment, but through the 1973 Endangered Species Act, the Fish and Wildlife Service has a legal mandate to protect endangered species throughout the country. Thus, this paper asks: What is the USFWS doing inside cities to recover endangered species? What are cities doing? Conservation is a shared duty but it is not clear that anyone is taking responsibility for urban endangered species.  相似文献   

辽河三角洲湿地生物多样性功能评价     

王金爽 《湿地科学与管理》2013,(2):38-39

在辽河三角洲湿地生物多样性调查的基础上,对辽河三角洲生物多样性进行评价,主要包括物种多样性和生态系统多样性。按照生物多样性评价标准,辽河三角洲湿地生物多样性处于一般水平,需要加大湿地生物多样性的保护力度。  相似文献   

Potentially harmful World Bank projects are proximate to areas of biodiversity conservation importance     

《Global Environmental Change》2021

For many countries in the global south the World Bank is a key funder of development. A subset of the activities it funds have the potential to cause harm to biodiversity. Currently, however, little is known about the spatial coincidence of Bank-funded projects and important areas for biodiversity. Using a dataset of World Bank projects funded between 1995 and 2014, we examine the relationship between potentially harmful project activities and the ranges of globally threatened birds, mammals, and amphibians, Key Biodiversity Areas, protected areas, and biodiversity hotspots. We find that 5 by 5 km cells containing a project activity are more likely to contain a Key Biodiversity Area, or a biodiversity hotspot, and have on average greater richness of globally threatened species, than those without. This relationship was statistically significant even after considering human population and country-level socio-economic effects except in the case of Key Biodiversity Areas. We also found limited evidence that activities are systematically placed within countries to avoid the ranges of threatened species or Key Biodiversity Areas. By contrast, we found a negative relationship between project activities and protected areas globally and within most countries, which may be evidence that potentially harmful activities are placed to avoid protected areas. Our findings raise questions about whether the Banks environmental safeguards have adequately translated into avoidance of highly diverse areas. Given the size of the World Bank’s lending portfolio and its role in setting industry best practice our results are concerning for conservation efforts.  相似文献   

Ecological and functional roles of mycorrhizas in semi-arid ecosystems of Southeast Spain   总被引：4，自引：0，他引：4  

J.M. Barea  J. Palenzuela  P. Cornejo  I. Sánchez-Castro  C. Navarro-Fernández  A. Lopéz-García  B. Estrada  R. Azcón  N. Ferrol  C. Azcón-Aguilar 《Journal of Arid Environments》2011,75(12):1292-1301

Mycorrhizas are worldwide symbiotic associations established between certain soil fungi and most vascular plants and are fundamental in optimizing plant fitness and soil quality. Mycorrhizal symbioses improve the resilience of plant communities against environment stresses, including nutrient deficiency, drought and soil disturbance. Since these stresses are paramount in the degradation of semi-arid ecosystems in the SE Spain, a series of basic, strategic and applied studies have been made to ascertain how the activity and diversity of mycorrhizal fungi affect plant community composition, structure and dynamics in this region. These investigations are reviewed here in terms of: (i) analysing the diversity of mycorrhizal fungi; (ii) assessing the ecological and functional interactions among plant communities and their associated mycorrhizal fungal populations; and (iii) using mycorrhizal inoculation technology for the restoration of degraded semi-arid areas in Southeast Spain. Disturbance of the target semi-arid ecosystems decreases the density and diversity of mycorrhizal fungust populations. Nevertheless, the mycorrhizal propagules do not disappear completely suggesting a certain degree of stress adaptation, and these remaining, resilient ecotypes are being used as plant inoculants. Numerous field experiments, using plant species from the natural succession inoculated with a community of indigenous mycorrhizal fungi, have been carried out in revegetation projects in the semi-arid Iberian Southeast. This management strategy improved both plant development and soil quality, and is a successful biotechnological tool to aid the restoration of self-sustaining ecosystems. However, despite a 20-year history of this work, we lack a comprehensive view of the mycorrhizal potential to improve the composition, diversity, structure and functionality of drought-adapted plant communities in the Region.  相似文献