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| Author(s): |
Mario José Marques Azevedo
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | Campinas, SP. |
| Institution: | Universidade Estadual de Campinas (UNICAMP). Instituto de Biologia |
| Defense date: | 2013-02-22 |
| Examining board members: |
Fernando Roberto Martins;
Marco Antonio Portugal Luttembarck Batalha;
Flavio Antonio Maës dos Santos
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| Advisor: | Roque Cielo Filho; Fernando Roberto Martins |
| Abstract | |
The resource utilization patterns and ecological niche theory are important in understand how communities are assembled. The way how resources are apportioned between species are showed in its abundance distribution. Abundance and diversity are outcome of process that structure communities. The pattern frequently found is a "hump-back" relationship between diversity and productivity. Competitive processes are inferred in determination of diversity along productivity gradient. Due to species abundance are outcome of biological interaction, models of species abundance distribution (SAD) allow us to infer how niche are apportioned. We use Tokeshi's SADs models and dominance and evenness index to test, using regression, how richness, biomass and evenness change along stress nutrition gradient defined by aluminium concentration in soil. We verified a negative linear pattern between richness and nutrition stress gradient with semideciduous forest fragment at extreme of lesser stress gradient and cerradão at opposite extreme gradient. The biomass showed a "U" shape pattern along the same gradient. The index and SADs models showed similar result measuring dominance of few species at extremes of gradient, however only Evar index measured more evenness between extremes of gradient. Our results allow inferring that such gradient war important to define community richness and biomass. The models and index allowed testing the patterns of niche apportionment, however its do not allowed us confirm the process of niche apportionment (AU) | |