Conservation of the diversity of shade-tolerant plants of agricultural mosaics in the eastern Amazon

With the increase in deforestation associated with the need to reconcile conservation and food production, agricultural mosaics are of great importance in maintaining biodiversity. This study aimed to compare the shade-tolerant plants diversity partition pattern and the conservation value (CV) presented by land-use types found in three vertical strata (upper, middle, and lower) of six agricultural mosaics in the eastern Amazon. Additionally, we hypothesized that agricultural mosaics with lower forest cover, with lower heterogeneity of land-uses, and drier areas have lower shade-tolerant plants diversity, and CV of land-use types. Plant surveys were carried out in family farming mosaics with fixed plots; a matrix of species abundance per plot was set up for each mosaic and stratum. Additive partition and absolute contribution analyze were applied to each matrix; and CV of the land-uses for gamma richness was calculated. Factors were tested using generalized linear models and simple linear regression. Our results indicate that there is a diversity pattern that is repeated in the strata and agricultural mosaics. Beta diversity, especially among land-use types, is the one that most contributes to the diversity. Habitat heterogeneity is very important for the conservation of shade-tolerant species, but it is not the number of different land-use types but what these land-uses are. Land-uses with low CV do not add diversity to the mosaic. Consequently, the quality of the environmental matrix is very important. This information will be useful in providing baseline data on the management of agricultural mosaics in the eastern Amazon.