Population structure, growth and production of the surf clam Donax hanleyanus (Bivalvia: Donacidae) from northern Argentinean beaches

The surf clams Mesodesma mactroides Reeve, 1854 and Donax hanleyanus Philippi, 1847 are the two dominating species in macrobenthic communities of sandy beaches off northern Argentina, with the latter now surpassing M. mactroides populations in abundance and biomass. Before stock decimation caused by exploitation (during the 1940s and 1950s) and mass mortality events (1995, 1999 and 2007) M. mactroides was the prominent primary consumer in the intertidal ecosystem and an important economic resource in Argentina. Since D. hanleyanus was not commercially fished and not affected by mass mortality events, it took over as the dominant species, but did never reach the former abundance of M. mactroides. Currently abundance and biomass of both surf clams are a multiple smaller than those of forty years ago, indicating the conservation status of D. hanleyanus and M. mactroides as endangered. Therefore the aim of this study is to analyse the population dynamics (population structure, growth and reproductive biology) of D. hanleyanus and M. mactroides, and to compare the results with historical data in order to detect possible differences within surf clam populations forty years ago and at present.

Epiphytic orchid diversity found on trees and shrubs in coffee cultivated Afromontane rainforest, SW Ethiopia

The moist evergreen Afromontane forest of SW Ethiopia has become extremely fragmented and most remnants are intensively managed for cultivation of coffee (Coffea arabica). We investigated the distributions of epiphytic orchids in shade trees and their understory in forests with contrasting management intensity to determine biodiversity losses associated with coffee cultivation and to determine the capacity of coffee shrubs to act as refugia for orchid species. We studied epiphytic orchids in managed forests and natural forests and recorded orchid diversity and abundance in different tree zones of 339 trees and in the understory. Coffee management was associated with a downward shift of orchid species as orchid species were occurring in significantly lower tree zones in managed forest. The number of shrubs in the understory of managed forest was not higher than in natural forests, yet orchid abundance was higher in the understory of managed forests. Local extinctions of epiphytic orchids and species losses in the outer tree zones (a contraction of habitat) in managed forests are most likely driven by losses of large, complex-structured climax trees, and changes in microclimate, respectively. Coffee shrubs and their shade trees in managed forests are shown here to be a suitable habitat for only a limited set of orchid species. As farmers continue to convert natural forest into managed forest for coffee cultivation, further losses of habitat quality and collateral declines in regional epiphytic orchid diversity can be expected. Therefore, the conservation of epiphytic orchid diversity, as well as other components of diversity of the coffee forests, must primarily rely on avoiding coffee management intensification in the remaining natural forest. Convincing farmers to keep forest-climax trees in their coffee forest and to tolerate orchids on their coffee shrubs may also contribute to a more favorable conservation status of orchids in Ethiopian coffee agroecosystems.

Bird species recorded in an untrained observer survey (UOS) and an expert observer survey (EOS) in 2011 in SE Peru

To evaluate the potential of community-based bird surveys in the tropics, we compared the species richness and abundances of bird functional groups that would be detected by a basic untrained observer (untrained observer survey, UOS) to a comprehensive bird species list compiled by a professional bird guide, in a coffee agroforestry landscape in the Peruvian East Andean foothills and compared functional signatures to global functional signatures of tropical bird assemblages. The submitted data comprises the transect counts of the UOS, the comprehensive bird list, ecological data of the recorded birds and information regarding the conservation status of the recorded birds from the IUCN Red List.

Mapped distribution of intertidal habitats in Australia between 1999 and 2014, link to data in ArcGIS format (29 MB)

Shorebirds have declined severely across the East Asian-Australasian Flyway. Many species rely on intertidal habitats for foraging, yet the distribution and conservation status of these habitats across Australia remain poorly understood. Here, we utilised freely available satellite imagery to produce the first map of intertidal habitats across Australia. We estimated a minimum intertidal area of 9856 km**2, with Queensland and Western Australia supporting the largest areas. Thirty-nine percent of intertidal habitats were protected in Australia, with some primarily within marine protected areas (e.g. Queensland) and others within terrestrial protected areas (e.g. Victoria). In fact, three percent of all intertidal habitats were protected both by both marine and terrestrial protected areas. To achieve conservation targets, protected area boundaries must align more accurately with intertidal habitats. Shorebirds use intertidal areas to forage and supratidal areas to roost, so a coordinated management approach is required to account for movement of birds between terrestrial and marine habitats. Ultimately, shorebird declines are occurring despite high levels of habitat protection in Australia. There is a need for a concerted effort both nationally and internationally to map and understand how intertidal habitats are changing, and how habitat conservation can be implemented more effectively.