Runoff-related agricultural impact in relation to macroinvertebrate communities of the Lourens River, South Africa

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A combined microcosm and field approach to evaluate the aquatic toxicity of azinphosmethyl to stream communities.

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Fate and effects of Azinphos-Methyl in a flow-through wetland in South Africa

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Ponds and the importance of their history: an audit of pond numbers, turnover and the relationship between the origins of ponds and their contemporary plant communities in south-east Northumberland, UK

An increasing focus of interest in ponds over the last two decades arose largely because of concerns at the loss of ponds in intensively developed landscapes. In the UK, pond numbers declined from approximately 800,000 in the nineteenth century to 200,000 by the 1980s. Since then pond numbers have started to increase. The focus on overall pond numbers overlooks the importance of the history and origins of different pond types. This study combines a detailed map based audit of pond numbers in south-east Northumberland, UK, recorded at seven time intervals since the mid nineteenth century with a survey of contemporary plant communities in ponds with known and distinct histories to examine changes to numbers of ponds and communities associated with ponds with different origins. 222 ponds were recorded in the study area in the midnineteenth century, 257 in 2005/08. However, only 23 of the original ponds had survived with substantial losses and gains at all the map survey dates linked to changed land use from agriculture to coal mining then development of nature reserves and golf courses. Contemporary ponds on nature reserves, golf courses and subsidence ponds supported rather different plant communities to each other, with non-native invasives in golf and nature reserve sites, whilst individual reserves differed from one another perhaps due to intentional planting. Surviving old farm ponds were usually degraded. The results show that the history of ponds in a region can create an important cultural biodiversity which pond conservation strategies should incorporate

The temporal dynamics of temporary pond macroinvertebrate communities over a 10-year period

Ponds support a rich biodiversity. This arises in part because of the number and heterogeneity of ponds spatially throughout the landscape. Studies of ponds suggest that distinct communities develop within individual ponds but most examples are based on shortterm 1- or 2-year surveys which cannot identify the effects of historic events upon contemporary communities. This study reports the development and turnover of the early summer macroinvertebrate communities in thirty small temporary ponds fromtheir creation in 1994 over 10 years to 2004. Distinct pioneer communities established in the first year of the ponds’ creation, the first 3 years dominated by a fauna associated with long summer dry phases. Then a sustained period of inundation lasting 27 months from summer 1997–1999 resulted in establishment of many taxa associated with permanent ponds and loss of some temporary pond species. The re-establishment of summer dry phases in 1999 was associated with the loss of some but not all of the permanent water taxa and re-colonisation by some temporary water species creating new communities combining these different elements. The communities were not a linear successional sequence; the communities that re-assembled following resumption of dry phases reflected the contingent history of each pond and the effects of historic events. The longer term nature of the study showed that the characteristic heterogeneity of pond invertebrate communities occurs through time as well as spatially and that the richness and variety of contemporary communities, which is often hard to explain fromsnap-shot studies, is partly the result of historic events