Soil physical indicators of management systems in traditional agricultural areas under manure application

<div><p>ABSTRACT Studies of the successive application of manure as fertilizer and its combined effect with long-term soil management systems are important to the identification of the interdependence of physical attributes. The aim of this study was to evaluate changes in the physical properties of a Rhodic Kandiudox under management systems employing successive applications of pig slurry and poultry litter, and select physical indicators that distinguish these systems using canonical discriminant analysis (CDA). The systems consisting of treatments including land use, management and the application time of organic fertilizers are described as follows: silage maize under no-tillage (NT-M7 years); silage maize under conventional tillage (CT-M20 years); annual pasture with chisel plowing (CP-P3 years); annual pasture with chisel plowing (CP-P15 years); perennial pasture without tillage (NT-PP20 years); and no-tillage yerba mate (NT-YM20 years) and were compared with native forest (NF) and native pasture (NP). Soil samples were collected from the layers at the following depths: 0.0-0.05, 0.05-0.10, and 0.10-0.20 m, and were analyzed for bulk density, porosity, aggregation, flocculation, penetration resistance, water availability and total clay content. Canonical discriminant analysis was an important tool in the study of physical indicators of soil quality. Organic fertilization, along with soil management, influences soil structure and its porosity. Total porosity was the most important physical property in the distinction of areas with management systems and application times of manure for the 0.0-0.05 and 0.10-0.20 m layers. Soil aeration and micropores differentiated areas in the 0.05-0.10 m layer. Animal trampling and machinery traffic were the main factors inducing compaction of this clayey soil.</p></div

Morphological Diversity of Coleoptera (Arthropoda: Insecta) in Agriculture and Forest Systems

<div><p>ABSTRACT Coleopterans (Coleoptera) are major ecosystem service providers. However ecomorphological features that are comparable in a wide range of invertebrates within this group and in various environments must be found, to be able to study regions with different species, contributing to overcome difficulties of the taxonomic approach and understand the functioning of ecosystems. This research addressed the diversity of Coleoptera, using a methodology of ecomorphological traits, as well as their relation with the land use systems (LUS) and the soil properties. The following LUS were evaluated: no-tillage (NT), crop-livestock integration (CLI), pasture (PA), Eucalyptus stands (EST), and native forest (NF). Samples were collected using a 3 × 3 point grid (sampling points at a distance of 30 m), in winter and summer, in three municipalities on the Southern Santa Catarina Plateau, Brazil. Coleopterans were collected using the methodology recommended by the Tropical Soil Biology and Fertility Program, based on the excavation of soil monoliths, and on pitfall traps. To evaluate the biological forms (morphotypes) and ecomorphological groups, the ecomorphological index (EMI) methodology was adopted and the modified soil biological quality (SBQ) index was determined. At the same points, samples were collected to evaluate environmental variables (soil physical, chemical, and microbiological properties). Density data underwent nonparametric univariate statistical analysis and multivariate abundance to verify the distribution of coleopterans in the LUS, and the environmental variables were considered as explanatory. Regardless of the LUS, 14 morphotypes were identified, and adult coleopterans with epigean morphologic adaptations were more abundant than hemi-edaphic and edaphic coleopterans, respectively. Morphotype diversity was higher in the systems NF, EST, and PA in summer and in NT in winter. The reductions in SBQ index were not associated with a gradient of land use intensification (NF> EST> PA> CLI> NT), and the index was higher for NF and lower for EST. Principal component analysis (PCA) indicated a different distribution of invertebrates between the LUS. For the edaphic species, better adapted to life in the soil, a relation with NT and CLI was observed, due to more favorable pH values and phosphorus content. In the NF, a greater amount of morphotypes was identified, and the properties related to soil carbon dynamics contributed to explain this distribution. Separation at the morphotype level, taking adaptation level to soil life into consideration, has proved efficient to discriminate the LUS, mainly along with other explanatory environmental variables.</p></div

FLORISTIC COMPOSITION AND PHYTOGEOGRAPHY CONTEXTUALIZATION OF THE NATURAL REGENERATION OF AN ALLUVIAL FOREST LOCATED IN THE "PLANALTO SUL CATARINENSE" REGION, SC, BRAZIL

<div><p>ABSTRACT This study aimed at inventorying the natural regeneration of tree species in an Alluvial Araucaria Forest in the "Planalto Sul Catarinense" region, SC, Brazil; evaluating the dissimilarity between its adult and regenerative components; and verifying the natural regeneration floristic sharing among its different fragments. The regenerative component has been sampled and identified within 48 plots and classified according to the following height classes: Class 1, plants with height varying from 15 cm up to 1 m; Class 2, plants with height varying from 1 and 3 m; and Class 3, plants with height higher than 3 m and DBH (diameter at breast height) smaller than 5 cm. The floristic composition of adult individuals in the area and of regenerative individuals from other fragments has been obtained from the database of the Laboratory of Dendrology of CAV/UDESC. The structure of the regeneration was evaluated by phytosociological descriptors. Dissimilarity between the adult and the regenerative components has been determined by Jaccard, Sorensen and Bray-Curtis distances. The regeneration floristic sharing analysis of different areas was conducted by a dendrogram. A total of 818 individuals belonging to 59 species have been sampled, being Allophylus edulis (A.St.-Hil. et al.) Hieron. ex Niederl. the species with the greatest relative importance. Elevated similarity between the regenerative and adult components have been observed (from 0.24 to 0.43), suggesting a low floristic-structural turnover between components. The area under study have shown a greater floristic connection (<40% of dissimilarity) with other spatially close fragments, indicating that altitude and temperature are important ecological factors for its phyto-geographic compartmentalization.</p></div