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Introduction: Coffee is a highly mycotrophic plant, its interaction with arbuscular mycorrhizal fungi has been studied among different tropical countries. The majority of the published works indicates that coffee is benefited from the mycorrhizal association, where the AMF confers protection against pathogens and diseases, increases water absorption, as well as it increases the adaptation of the plant at transplant from nurseries to the main plantation. Objective: A review was made where we summarized and analyze the research reports of AMF with coffee from at least the past 10 years, focused on AMF global species distribution, nutritional benefits of the association and interaction with pathogens. Methods: We retrieved available bibliographic data from coffee producer countries in public databases. We considered published works from 2000 to 2019, nevertheless, we included classic papers on the topic, outside that period, mainly the ones performed in Brazil since 1986. We organized the number of reported species per country, we look for synonyms, grouped them by family, genera and species. The reports that only reported genera or where ambiguous were used as reference but not considered for the final analysis. We summarized the reports of the benefits of the AMF interaction in coffee, as well as pathogen tolerance. Results: The collected data shows that there are more than 100 AMF species associated with coffee, which represents more than a third part of the total of reported species worldwide. We found that Colombia has the highest richness, but it also has the highest number of published reports. Conclusions: This information shows the benefits of the incorporation of AMF to coffee plantation programs, because these fungi are a key element in coffee plant nutrition, nevertheless, the coffee variety should be considered when introducing AMF, as not all associations has been efficient. [ABSTRACT FROM AUTHOR]

Holothuria grisea, despite not being considered a commercial resource has been the subject of illegal extractions in Colombia, a fact that becomes more serious due to the empty of biological information of these organisms. For this reason the density population and size structure of H. grisea were evaluated in three sectors south of the gulf of Morrosquillo from April to November 2015. To this end, three circular transects were located each month in each sampling site covering an area of 300 m², where individuals were counted and measured in situ. The average density of H. grisea in the study area was 0.4 ind m-2, with the highest values in the La Ahumadera (1.09 ± 0.11 ind m-2) and the lowest values in Banco de Arena (0.02 ± 0.004 ind m-2). The analysis of variance showed a significance in the values of density and size of H. grisea in the studied sectors. The species presented a unimodal distribution of sizes with an average size of 13.5 ± 0.9 cm with a minimum size of 2.5 and a maximum of 30 cm, intermediate sizes generally showed a higher representativeness throughout this study (77.2%). The biological aspects presented in this paper are of great importance for the conservation of this species and corresponds to an advance in the knowledge of the Holothuroidea class in the Colombian Caribbean. [ABSTRACT FROM AUTHOR]

Forests structural differences could result of environmental variations at different scales. Because soils are an important component of plant's environment, it is possible that edaphic and structural variables are associated and that, in consequence, spatial autocorrelation occurs. This paper aims to answer two questions: (1) are structural and edaphic variables associated at local scale in a terra firme forest of Colombian Amazonia? and (2) are these variables regionalized at the scale of work? To answer these questions we analyzed the data of a 6ha plot established in a terra firme forest of the Amacayacu National Park. Structural variables included basal area and density of large trees (diameter≥10cm) (Gdos and Ndos), basal area and density of understory individuals (diameter<10cm) (Gsot and Nsot) and number of species of large trees (sp). Edaphic variables included were pH, organic matter, P, Mg, Ca, K, A1, sand, silt and clay. Structural and edaphic variables were reduced through a principal component analysis (PCA); then, the association between edaphic and structural components from PCA was evaluated by multiple regressions. The existence of regionalization of these variables was studied through isotropic variograms, and autocorrelated variables were spatially mapped. PCA found two significant components for structure, corresponding to the structure of large trees (G, Gdos, Ndos and sp) and of small trees (N, Nsot and Gsot), which explained 43.9% and 36.2% of total variance, respectively. Four components were identified for edaphic variables, which globally explained 81.9% of total variance and basically represent drainage and soil fertility. Regression analyses were significant (p<0.05) and showed that the structure of both large and small trees is associated with greater sand contents and low soil fertility, though they explained a low proportion of total variability (R2 was 4.9% and 16.5% for the structure of large trees and small tress, respectively). Variables with spatial autocorrelation were the structure of small trees, Al, silt, and sand. Among them, Nsot and sand content showed similar patterns of spatial distribution inside the plot. Rev. Biol. Trop. 59 (3): 1307-1322. Epub 2011 September 01. [ABSTRACT FROM AUTHOR]