Ethanol (EtOH) 70% is commonly used in collections to preserve and store many unprepared soft-bodied Chalcidoidea. Specimens air-dried directly from alcohol, however, often suffer from collapse of some body parts, making subsequent observation of their morphology difficult or even impossible. We propose an inexpensive method for processing and dry-mounting specimens of Chalcidoidea, using a chemical process including amyl acetate. Four treatments using amyl acetate at different concentrations and exposure times were evaluated for specimens of Eulophidae, Mymaridae, Encyrtidae, Aphelinidae, Pteromalidae, and Trichogrammatidae. Treatment with amyl acetate resulted in specimens of consistently higher quality. Based on our results, treatment of specimens for 1 h with 50:50 amyl acetate and ethanol mixture, followed by treatment for 1 h with 100% amyl acetate, yielded specimens adequate for morphological observations for most of the families. Further experiments are required, however, to optimize this approach for Trichogrammatidae and Eulophidae. This method is a relatively simple, inexpensive, and safe alternative to other methods commonly used for restoring Chalcidoidea preserved in alcohol.

The objective of this work was to evaluate the soil macrofauna and the bioindicator taxonomic groups associated with different land uses in the Colombian Amazon. Twelve agroforestry arrangements were studied and compared with to the native forest and pasture. For each land use, six monoliths were randomly selected and divided into four layers (litter, and 0-10, 10-20, and 20-30 cm soil depths). The variables considered in the analysis of land use effects were: individuals per square meter, order richness, Shannon’s diversity index, and Pielou’s evenness index. The greatest values for soil macrofauna density and diversity occurred in the forest, in contrast with the pasture. The principal component analysis distinguished land use according to macrofauna diversity, separating the native forest from the other land uses. The cluster analysis indicated the potential of some agroforestry systems to conserve the values of soil macrofauna density and diversity similar to those of the forest. According to the analysis of indicator value, five taxonomic groups (Diplura, Pseudoscorpionida, Araneae, Chilopoda, and Gastropoda), identified as bioindicators, are associated with preserved sites because of the sensitivity of their populations.

Silvopastoral systems (SPS), an integrated farming system in which tropical grasses are combined with trees and shrubs, have been implemented in the last years in the Amazon region in order to mitigate the impacts generated by the traditional cattle ranching system. However, despite the multiple SPS’s benefits to soil and ecosystem, there is a paucity of comprehensive studies revealing the potential soil health (SH) restoration through SPS. Here, by developing an overall SH index using local native vegetation (Amazon rainforest) as a reference, we aimed to assess SH changes induced by the land transition from the traditional livestock production system to the SPS in the Colombian Amazon region. A chronosequence conformed by three areas: (i) native vegetation, (ii) traditional pasture and (iii) silvopastoral system was established in two study sites located in the Colombian Amazon, specifically in Caquetá State, the second hotspot of deforestation in the Amazon Basin. The results indicated high soil compaction and loss of macrofauna diversity and richness due to pasture management, causing a loss of 9% of soil capacity to function. In contrast, by integrating 31 soil indicators, our SH assessment revealed that SPS was an effective strategy for the recovery of SH, impacting positively multiple soil functions related to nutrient dynamics, water retention and supply, and biological activity.

Conversion from Amazon forest to low-management pasture or agriculture causes not only degradation of aboveground vegetation but also negative changes in soil properties and ecosystem services. This study aimed to evaluate the impact of physical soil degradation on termite community changes in three contrasting land uses (natural regeneration, rubber plantations, and silvopastoral systems). Soil physical quality was assessed through a set of physical variables, such as bulk density, porosity, soil macro-aggregation state, Visual Evaluation of Soil Structure (VESS) and penetration resistance, which were summarized in an overall synthetic indicator of physical quality. Besides, transects of 20 × 2 m were established in each land use; each transect was divided into four sections of 5 m to search and collect termites during 1 hour in each section; likewise, termites were collected from blocks of soil 25 × 25 × 10 cm (length, width, and depth, respectively) adapted from the Tropical Soil Biology and Fertility (TSBF) method. In total, 60 transects were evaluated, 20 in each land use. A total of 41 species were collected across the three land uses evaluated: natural regeneration presented 60% of the collected species (25 species), silvopastoral systems 53% (22 species), and rubber plantations 39% (16 species). Additionally, composition species from the silvopastoral, agroforestry systems, and natural regeneration were different, and a close association between these last land uses was observed. Soil physical characteristics showed significant variations between land uses. The rubber plantations presented lowest values of soil physical quality, while the natural regeneration showed high soil physical quality. These changes affected termite community and lead to changes in its composition with disproportionate loss of some species; however, there are some that can acclimate well to the decline in the soil physical quality.