Browsing by Autor "Alejandro Coca‐Salazar"

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Macromycete fungal diversity in the Andean Amazonian rainforest of the Sacta Valley, Cochabamba, Bolivia
(2023) Mario Coca Morante; Alejandro Coca‐Salazar; Olga Herrera Fernández; Casimiro Mendoza Bautista
Deforestation has affected the pre-Andean Amazonian tropical rainforests, as microregions are of relevant ecological and environmental importance for biodiversity conservation. Macromycetes are some of the organisms facing extinction owing to the alteration of which the natural tropical rainforests have been subjected. This work provides an inventory of the macromycetes inhabiting the last relicts of natural, unspoiled rainforest of the Department of Cochabamba, Bolivia, and reports the advancements made in their identification and classification. The inventory was taken in the permanently monitored plots established within the primary forest preserved by the San Simón University at the Valley of Sacta Fund. We found sixty-two different morphotypes, fifty-five of which are macromycetes and seven are not polypores. Fifty morphotypes were categorized as saprophytes living on dead trunks and branches and twelve morphotypes parasitizing living trunks of 17 tree species. Low macromycete species richness and the Shannon index (3.78) are indicative of low macrofungal diversity.
Plant communities on the islands of two Altiplanic salt lakes in the Andean region of Bolivia
(Pensoft Publishers, 2016) Alejandro Coca‐Salazar; Huber Villca; Mauricio Torrico; Fernando D. Alfaro
This paper reports a quantitative survey of the composition, diversity and structure of the plant communities on six islands of Uyuni and Coipasa salt lakes (Bolivia). Plant communities on each island were examined via the use of 10 transects, along which species richness and abundance were recorded. Seventy-one species were found in total, representing pteridophytes (6%), gymnosperms (1%), monocotyledons (14%) and dicotyledons (79%). About 21% of the species were endemic or faced some degree of threat. The calculation of Shannon-Wiener α-diversity indices and comparisons of community structure revealed similarities between the islands. Indeed these analyses suggest the existence of a single floral assemblage; however, small differences in the plant communities were visually identified during fieldwork. These islands are home to a considerable subset of the Altiplano’s flora and appear to have been little disturbed. They should therefore be the subject of surveillance/conservation programs.
Response of ammonia-oxidizing bacteria and archaea abundance and activity to land use changes in agricultural systems of the Central Andes
(Elsevier BV, 2020) Alejandro Coca‐Salazar; Agnès Richaume; Alessandro Florio; Monique Carnol
Soil properties and microbial processes in response to land‐use change in agricultural highlands of the <scp>Central Andes</scp>
(Wiley, 2021) Alejandro Coca‐Salazar; Jean‐Thomas Cornelis; Monique Carnol
Abstract Understanding changes in soil functions in response to land‐use change is important for guiding agricultural practices towards sustainable soil management. We evaluated the differences in soil properties (soil organic matter, water extractable carbon (C) and nitrogen (N), microbial biomass, pH KCL and exchangeable cations) and microbial processes (respiration potential, net N mineralization, net nitrification and metabolic potential of soil bacteria), as well as the relative importance of soil properties in explaining changes in processes under three land uses (potato crops, fallow fields and eucalyptus plantations) in the agricultural highlands of the Central Andes. Soils under potato crops were characterized by the highest net N mineralization and net nitrification rates, and extractable phophorus (P), and the lowest microbial biomass P. Conversion to eucalyptus plantations led to an increase in soil organic matter, water extractable C and microbial biomass, and a decrease in extractable P and metabolic diversity of soil bacteria. Higher exchangeable aluminium (Al) indicated soil acidification under eucalyptus. Fallow practices did not lead to major changes in soil properties and microbial processes, indicating that fallow practices for up to 6 years were too short to substantially contribute to soil fertility restoration. Hot water extractable carbon (HWC) showed the best relationship with soil processes (respiration potential, net N mineralization and net nitrification). Our results highlight the necessity of alternative management practices for maintaining soil fertility under potato crops, the drastic modification of soil properties and processes under eucalyptus plantations, and the potential of HWC as a proxy for monitoring land‐use‐induced changes in soil functions related to C and N cycling. Highlights Effects of conversion from potato crops to eucalyptus and fallow on soil properties and processes were assessed. Under eucalyptus, soil respiration increased; metabolic diversity and N transformations decreased. Short fallow periods did not result in soil fertility restoration. Hot water extractable C was the best indicator of changes in soil processes.
Wild potato species (&lt;i&gt;Solanum&lt;/i&gt; section Petota &lt;i&gt;Solanaceae&lt;/i&gt;) in the Tunari National Park, Andean Region of Cochabamba, Bolivia
(Scientific Research Publishing, 2014) Mario Coca Morante; Alejandro Coca‐Salazar
The Tunari National Park is located in the Tunari Mountain Range, part of the Cochabamba Range in the Bolivian Andes. The Park is home to species of wild potato (Solanum section Petota Solanaceae), but these are now threatened by human activity. The aims of the present study were: 1) to determine the distribution of wild potato species in the Park, and, 2) to determine the size of their populations. Collection routes were established within the Park, and the species present along them recorded in 2006, 2007 and 2008. Their population sizes were determined in 2008. Four wild potato species were identified: S. capsicibaccatum, S. berthaultii, S. brevicaule and S. toralapanum. S. capsicibaccatum was the most abundant and had the most extensive distribution, followed by S. berthaultii; these last two species are likely endemic. The other species, although probably also endemic, were much less widely distributed; some limiting factor(s) would therefore appear to be acting upon them. S. berthaultii showed variations in corolla shape (rotate, pentagonal and semi-stellate) and flower colour (whitish-lilac to blue-lilac). The remaining species showed no apparent intraspecific variation in their morphological characteristics.