Seasonal changes in vegetation and climate exert significant influences on soil fauna in natural and agricultural ecosystems. Additionally, evidence indicates that interactions between different plant layers promote soil fauna diversity through the variety of resources available. The objective was to assess the edaphic fauna in traditional land use systems, agroforestry systems and natural vegetation, under the influence of rainfall seasonality and plant strata in the semiarid region of Brazil. For this purpose, six types of land use were selected: agroforestry; silvopastoral; slash and burn with intensive use without fallow; slash and burn with six years of fallow; slash and burn with nine years of fallow; and a system representing the natural vegetation of the Caatinga. Edaphic fauna was collected using pitfall traps in the dry and rainy seasons. A total of 43,363 individuals of the edaphic fauna were collected and grouped into taxa, determining abundance, diversity and functional groups. The results revealed higher abundance and diversity of edaphic fauna in the rainy season across all land use systems, but significantly higher numbers in systems with tree strata. The greater the abundance, richness and diversity of trees, the higher the diversity of edaphic fauna (Shannon Index - H: 0.7 < H- < 1) for the seasonal effect. Agroforestry systems were intermediate in the diversity of edaphic fauna (H- < 0.8) compared to other systems. Systems with greater heterogeneity in tree and herbaceous strata were the ones that most increased the diversity and activity of functional groups of edaphic fauna (H < 0.8; 0.5 < r < 0.9). In semiarid conditions, more attention should be given to agricultural production systems with greater tree diversity and interaction between tree and herbaceous strata to conserve the biodiversity of edaphic fauna and improve the soil health.

Context The failure of the Fund & atilde;o dam devastated a large area of the Atlantic Forest, causing damage to and loss of riparian forests. Considering all the ecological roles of a terrestrial and freshwater community, it is necessary to understand the functioning of riparian forests and their regenerative potential, which will be decisive in selecting actions to restore these ecosystems, especially Atlantic Forest remnants. Aims We evaluated the flora and structure of the regenerating stratum in three riparian vegetation remnants along the Rio Doce basin to support the propagation and restoration of the affected environments. Methods Plots of 5 m x 5 m were made in each area, totalling 77 sampling units. In these plots, all woody individuals with a diameter at soil height (DSH) of at least >= 1 cm and diameter at breast height (1.3 m from the soil) of at least <5 cm were marked, measured (in height and DSH), sampled and identified. Key results A total of 275 species distributed in 47 families were sampled, with Fabaceae the most diverse family and Siparuna guianensis Aubl. the most abundant species. Variation in beta diversity was significant, and composition analysis showed that plots of each area tended to cluster. Principal component analysis and linear models showed that the edaphic parameters were not related to the richness and abundance of species in the sampled areas. Conclusions The areas sampled here serve as a reference for the restoration of impacted areas. Implications This study represents an important step towards knowing the species in reference areas for an active and efficient restoration in impacted areas.

Questions: Are there changes in species composition of the oceanic, Low-Arctic tundra vegetation after 40 years? Can possible changes be attributed to climate change? Location: Ammassalik Island near Tasiilaq, Southeast Greenland. Methods: Species composition and cover of 11 key vegetation types were recorded in 110 vegetation survey plots in 1968-1969 and in 11 permanent plots in 1981. Recording was repeated in 2007. Temporal changes in species composition and cover between the surveys were tested using permutation tests linked with constrained ordinations for vegetation types, and Mann-Whitney tests for individual species. Changes in vegetation were related to climate change. Results: Although climate became warmer over the studied period, most of the vegetation types showed minor changes. The changes were most conspicuous in mire and snowbed vegetation, such as the Carex rariflora mire and Hylocomium splendens snowbed. In the C. rariflora mire, species number and cover of vascular plants and cover of bryophytes increased, whereas in the H. splendens snowbed species numbers of vascular plants, bryophytes, and also lichens increased. Lichen richness increased in the Carex bigelowii snowbed and cover of bryophytes in the Salix herbacea snowbed. No such changes occurred in the Alchemilla glomerulans meadow, Alchemilla alpina snowbed and Phyllodoce coerulea heath. There was no change of species composition within the Salix glauca scrub, A. alpina snowbed, lichen grassland and the Empetrum nigrum and Phyllodoce coerulea heaths. Most changes resulted from increasing frequency or cover of some species; there were very few decreasing species. Most of the increasing species indicate drier substrate conditions. Conclusions: Only minor changes in species composition and cover were detected in the vegetation types studied. These changes were probably caused by milder winters and warmer summers during the years before the 2007 sampling. Climate warming may have reduced the duration of snow cover and soil moisture, particularly in snowbed and mire habitats, where species composition change was most pronounced. However, its magnitude was insufficient to cause a major change in species composition. Thus, on the level of plant community types, tundra vegetation near Tasiilaq was rather stable over the last 40 years.