ABSTRACT
Abstract The Sierra Madre del Sur (SMS) concentrates the greatest plant diversity in Mexico (9,524 species) and 10% of the endemism. And 8.3% of its surface is covered by Natural Protected Areas (NPAs). Strategies to create NPAs are based on identifying biodiversity hotspots to preserve the maximum number of species with the least resources. Areas with high biodiversity reflect geographic patterns and evolutionary processes useful for designing NPAs. The objectives were: were 1) to identify Priority Areas for Conservation (PACs) in the SMS based on taxonomic richness, endemism, and phylogenetic diversity, and 2) to seek the geographic congruence of the identified PACs with current NPAs. In a 10 × 10 km grid cell, indices of taxonomic richness, weighted endemism, and phylogenetic diversity were calculated for a set of 9,524 species. Furthermore, consensus areas of endemism were identified for a total of 1,133 endemic species. In the SMS, 33 consensus areas of endemism were rescued, and the taxonomic richness, weighted endemism, and phylogenetic diversity were heterogeneous and 94% correlated. Similarly, 27 PACs were identified. Three NPAs completely cover four PACs, 12 PACs are partially found in three NPAs, and in 38 Areas Voluntarily Designated for Conservation (AVDCs). Finally, 12 identified PACs are not found within any NPA. In the SMS it is necessary to promote the establishment of new NPAs or AVDCs that protect with high plant diversity.
Resumen La Sierra Madre del Sur (SMS) concentra la mayor diversidad vegetal en México (9,524 species) y el 10% del endemismo y el 8.3% de su superficie está cubierta por Áreas Naturales Protegidas (ANPs). Las estrategias para crear ANPs se basan en identificar hotspots de biodiversidad con la finalidad de preservar el máximo número de especies con la menor cantidad de recursos. Las áreas con alta biodiversidad reflejan patrones geográficos y procesos evolutivos útiles para el diseño de ANPs. Los objetivos fueron: 1) identificar Areas Prioritarias para la Conservación (APCs) en la SMS con base en la riqueza taxonómica, endemismo y diversidad filogenética, y 2) buscar la congruencia geográfica para las APCs identificadas con las ANPs actuales. En una cuadrícula de celdas de 10 × 10 km, se calcularon los índices de riqueza taxonómica, endemismo ponderado y la diversidad filogenética para un conjunto de 9,524 especies. Además, se identificaron áreas de consenso de endemismo para 1,133 especies endémicas. En la SMS, se rescataron 33 áreas de consenso de endemismo y la riqueza taxonómica, el endemismo ponderado y la diversidad filogenética fueron heterogéneos y estuvieron correlacionados en un 94%. Así mismo, se identificaron 27 APCs. Tres ANPs cubren en su totalidad cuatro APCs, 12 APCs se encuentran de manera parcial en tres ANPs y en 38 áreas destinadas voluntariamente para la conservación (ADVCs). Por último, 12 APC identificadas no se encuentran dentro de alguna ANP. En la SMS es necesario fomentar la creación de nuevas ANPs o ADVCs que resguarden los sitios con alta diversidad vegetal.
ABSTRACT
Aquatic macroinvertebrate diversity and composition in streams along an altitudinal gradient in Southeastern Brazil. A study concerning taxonomic richness and composition of the aquatic insect fauna in streams within the same catchment basin along an altitudinal gradient in Southeast Brazil, was conducted to test the hypothesis that there is a faunal discontinuity in the biocenotic composition, related to differences in altitude and latitude. In Southeastern Brazil, around latitude 22°, this faunal transition from rhithron to potamon biocenosis should occur at 500 m above sea level. Eighteen tributaries of the Mambucaba River, at Serra da Bocaina National Park, SP-RJ, Brazil, were studied. The streams were separated into 6 altitudinal zones (zone 1: above 1500 m; zone 2: 1200-1300 m; zone 3: 900-1000 m; zone 4: 400-700 m; zone 5: 100-300 m; and zone 6: 0-100 m) each including three streams. The aquatic insects were identified at the lowest possible taxonomic level. The highest richness was observed in altitudes between 1200-1300 m, while the lowest occurred in altitudes below 100 m. The Indicator Value method indicated taxa characteristic for four of the six altitudinal zones considered in this paper. Sorensen's Index and CCA results showed that distribution and composition of aquatic insect fauna of Serra da Bocaina National Park was influenced primarily by altitude and temperature rather than stream size. The absence of indicator species and the lower abundance in altitudes between 400-700 m suggest a transition from rhithral to potamal fauna, which is distinct at 200 m.
Riqueza de macroinvertebrados aquáticos em riachos ao longo de um gradiente altitudinal no Sudeste do Brasil. Um estudo da riqueza e composição da fauna de insetos aquáticos de uma bacia hidrográfica com ênfase no gradiente altitudinal foi conduzido com o objetivo de testar a hipótese de que existe uma descontinuidade na composição da fauna relacionada à altitude e latitude. Na região Sudeste do Brasil, próxima à latitude 22°, a transição da fauna ritral-potamal deveria ocorrer em torno de 500 m. Com este objetivo central foram estudados 18 afluentes do Rio Mambucaba, Parque Nacional da Serra da Bocaina, SP-RJ, divididos em 6 faixas altitudinais (faixa 1: acima de 1500 m; faixa 2: 1200-1300 m; faixa 3: 900-1000 m; faixa 4: 400-700 m; faixa 5: 100-300 m e faixa 6: 0-100 m), sendo amostrados três riachos por faixa de altitude. Os insetos aquáticos foram identificados até o menor nível taxonômico possível. A maior riqueza foi observada nas altitudes entre 1200-1300 m, enquanto a menor riqueza ocorreu em altitudes inferiores a 100 m. O teste de espécies indicadoras mostrou táxons característicos para quatro das seis zonas altitudinais consideradas no presente trabalho. Os resultados do índice de Similaridade de Sorensen e da CCA mostraram que a comunidade de insetos aquáticos do Parque Nacional da Serra da Bocaina foi influenciada primariamente pela altitude e temperatura mais do que o tamanho do rio. A ausência de táxons indicativos, associada a menor riqueza de táxons e menor abundância entre as altitudes de 400-700 m sugerem uma zona de transição da fauna ritral para a fauna potamal, a qual parece ser distinta a 200 m.