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Carlos Frankl Sperber Kazuiyuki Nakayama Maria Júlia Valverde Frederico de Siqueira Neves 《Basic and Applied Ecology》2004,5(3):241-251
In Brazil, cacao is mostly planted beneath shade trees. The diversity of shade trees varies from monospecific to highly diverse canopies, characteristic of pristine Atlantic Forest. This study evaluates the relationships between family richness of Hymenoptera-Parasitica and Chrysidoidea, and tree species richness and density, the species richness of herbaceous understorey, and the area and age of the cacao agroforestry system. We sampled 16 cacao agroforestry systems, with canopy diversity ranging from one to 22 tree species per hectare, in three seasons: summer (March), winter (August) and spring (November). Parasitoids were sampled using eight Malaise-Townes traps per site. Tree species richness and density were enumerated within 1 ha at each site, and herbaceous plant species richness was calculated in eight 1 m2 plots, within the hectare. The number of parasitoid families increased with tree species richness and density in spring and summer, but decreased in winter. Neither species richness of herbaceous plants nor area and age of the system affected parasitoid family richness. We suggest that the increase of parasitoid diversity with tree species richness and density in warmer seasons reflects increasing heterogeneity and availability of resources. The decrease in parasitoid family number with tree density in winter may be due to local impoverishment of resources, leading to parasitoid emigration to neighbouring forest remnants. This result implies that a higher diversity of shade trees will help to maintain high parasitoid levels and, in consequence, higher levels of natural enemies of cacao pests, particularly in the warmer seasons. This prediction is borne out in the experience of cacao producers. The proper management of shade tree diversity will play a vital role in maintaining the sustainability of cacao agroforestry production systems in the tropics and, concurrently, will maintain high biodiversity values in these locations. 相似文献
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Bat and Bird Assemblages from Forests and Shade Cacao Plantations in Two Contrasting Landscapes in the Atlantic Forest of Southern Bahia, Brazil 总被引:3,自引:0,他引:3
Deborah Faria Rudi Ricardo Laps Julio Baumgarten Maurício Cetra 《Biodiversity and Conservation》2006,15(2):587-612
In the core region of Brazilian cocoa production, shade cacao plantations (so-called cabrucas) are important components of
regional landscapes, constituting potential habitat for a vast array of the regional biota. This research focuses on the ability
of cabrucas to harbor bird and bat species in two nearby districts – Una and Ilhéus – with contrasting landscapes. At Una,
cabrucas represent less than 6% of the land and are surrounded by large tracts of forest, whereas at Ilhéus these shade plantations
are the landscape's dominant feature. Bird and bat communities were richer in cabrucas located in Una compared to nearby forest,
while cabrucas from the Ilhéus landscape were significantly poorer in species than nearby forest fragments. However, bird
assemblages in cabrucas were characterized by the loss of understory specialists and the increase of more open area and generalist
species, whereas forest dwellers still comprised most of the bat species reported in cabrucas. Species richness and composition
differed between the two landscapes. Forest fragments and cabrucas from Ilhéus harbored fewer forest-dwelling species than
similar habitats in Una. Our study shows that cabrucas support high species richness of birds and bats from the native assemblages
but are no surrogates for intact forests, since the presence and representativeness of some forest species apparently depends
on the existence of nearby forests. A landscape dominated by cabrucas with a minor portion of native forest is unlikely to
ensure long-term conservation of many target species, particularly those of major conservation concern. 相似文献
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Jacques H. C. Delabie Benoît Jahyny Ivan Cardoso do Nascimento Cléa S. F. Mariano Sébastien Lacau Sofia Campiolo Stacy M. Philpott Maurice Leponce 《Biodiversity and Conservation》2007,16(8):2359-2384
By maintaining a forest-like structure, shaded cocoa plantations contribute to the conservation of ants that usually live
in the soil, leaf litter or canopy of tropical forests. Here we synthesize the available information on the diversity and
community structure of ants in shaded cocoa plantations in the Atlantic forest region of Brazil, compare ant assemblages in
cocoa agroforests with forests and other forms of agriculture, and discuss how these shaded plantations contribute to the
conservation of the ants in the Atlantic Forest region. We also discuss ants of economical importance and of special interest,
including Camponotus, Dolichoderus, Gnamptogenys, Pachycondyla, Pseudomyrmex and other litter dwelling genera. We discuss the situation of the tramp ant Wasmannia auropunctata in the Bahian cocoa-producing region where it is considered as native, and that of the two cryptobiotic genera Thaumatomyrmex and Typhlomyrmex, as well as that of proven and possible endangered army ant and Ponerini species. A total of 192 ant species from four strata
were found in extensive sampling of a cocoa plantation with a relatively simple shade canopy (comprised primarily of Erythrina). Species richness in the cocoa plantations corresponded roughly to that of low diversity native forests, and species composition
of cocoa plantations was most similar to native habitats (forest and mangroves) while ant composition in other agricultural
habitats was most similar to that of urban areas. Although occurrences of Wasmannia auropunctata were similar in cocoa plantations and forests, abundance of Thaumatomyrmex and Typhlomyrmex, generally thought to be rare ants, was relatively high in cocoa plantations. These results, from cocoa plantations with
relatively simple shade, demonstrate the importance of cocoa for ant conservation in the Atlantic forest region of Brazil.
It is likely that cocoa plantations with a greater number of vegetation strata and higher tree species richness (such as traditional
cabruca plantations) provide even more important habitat for ants generally and for ant species of conservation concern. 相似文献
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Deborah Faria Mateus Luís Barradas Paciencia Marianna Dixo Rudi Ricardo Laps Julio Baumgarten 《Biodiversity and Conservation》2007,16(8):2335-2357
The traditional shade cacao plantations (cabrucas) of southern Bahia, Brazil, are biologically rich habitats, encompassing
many forest-dwelling species. However, a critical question for the conservation management of this specific region, and the
highly fragmented Atlantic forest in general, is to what extent the conservation value of cabrucas relies on the presence
of primary forest habitat in the landscape. We investigated the relative importance of cabrucas and forests for the conservation
of five diverse biological groups (ferns, frogs, lizards, birds and bats) in two contrasting landscapes in southern Bahia,
one dominated by forest with some interspersed cabrucas, and one dominated by cabrucas with interspersed forest fragments.
The community structure (richness, abundance and diversity) of all biological groups differed between cabrucas and forests,
although these differences varied among groups. A high number of forest species was found in the cabrucas. However, there
were pronounced differences between the two landscapes with regard to the ability of cabrucas to maintain species richness.
Irrespective of the biological group considered, cabrucas located in the landscape with few and small forest fragments supported
impoverished assemblages compared to cabrucas located in the landscape with high forest cover. This suggests that a greater
extent of native forest in the landscape positively influences the species richness of cabrucas. In the landscape with few
small forest fragments interspersed into extensive areas of shade cacao plantations, the beta diversity of birds was higher
than in the more forested landscape, suggesting that forest specialist species that rarely ventured into cabrucas were randomly
lost from the fragments. These results stress both the importance and the vulnerability of the small forest patches remaining
in landscapes dominated by shade plantations. They also point to the need to preserve sufficient areas of primary habitat
even in landscapes where land use practices are generally favorable to the conservation of biodiversity. 相似文献
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