Roy Vera-Velez

Dr. Roy Vera-Velez


Research Focus & Metrics

Academic Career Length

5Years (2022-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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25 January 2023 in Rangeland Ecology & Management
Verified
Journal Article
Closed access
RVRoy Vera-Velez
Roy Vera-Velez
SGSera A. Grover
Sera A. Grover
BBBrendan K. Bischoff
Brendan K. Bischoff
CCCameron Carlyle
Cameron Carlyle
ELEric Lamb
Eric Lamb

1 April 2022 in Canadian Journal of Plant Science
Verified
Journal Article
Closed access
RVRoy Vera-Velez
Roy Vera-Velez
ELEric G. Lamb
Eric G. Lamb
The forage value of native forbs is rarely considered in pasture mixtures, even though such species can make up a substantial proportion of the diet of cattle on native rangelands. Incorporating non-leguminous forbs into pasture grazing systems can provide additional ecosystem services such as pollination habitat, and ideally those forbs would also provide some forage value. We therefore assessed the seasonal variation in protein and fiber [neutral detergent fiber (NDF) and acid detergent fiber (ADF)] content of six common western Canadian native forb and sub-shrub species: yarrow (Achillea millefolium), smooth aster (Symphyotricum laeve), prairie crocus (Pulsatilla patens), prairie rose (Rosa arkansana), Canada goldenrod (Solidago canadensis), and American vetch (Vicia americana). The legume V. americana displayed the highest protein followed by S. canadensis and S. laeve. V. americana also has the highest fiber concentration through the growing season. S. canadensis and S. laeve had lower fiber content; thus, making them a good choice for addition in seed mixes to meet the energy and nutrient requirements of cattle. Forb protein and fiber content showed opposite trends during the growing season. Crude protein decreased while NDF and ADF increased as a general pattern tied to physiological stage and degree of senescence. The promising nutritional profile of some forb species suggests that these species should be considered in pasture mixes.

23 May 2024 in Agronomy
Verified
Journal Article
Open access
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RVRoy Vera-Velez
Roy Vera-Velez
RVRaul Armando Ramos Veintimilla
Raul Armando Ramos Veintimilla
JGJorge Grijalva-Olmedo
Jorge Grijalva-Olmedo
Mixed production systems play a vital role in the economic sustainability and ecological balance of agroecosystems. Cocoa and plantain are key crops in Ecuador but face phytosanitary challenges, like witches’ broom and black sigatoka diseases, especially when cultivated under monocropping systems. Combining habitat manipulation with adaptive pathogen management (APM) strategies can mitigate these challenges, but their efficacy in mixed cropping systems remains unclear. This study investigates disease and pest incidence in mixed cocoa–plantain systems during the establishment phase, focusing on the impact of spatial arrangements. Mixed agroecosystems showed a lower witches’ broom incidence in cocoa than monocultures. Whereas, in plantain, there was a consistent black sigatoka incidence across spatial arrangements but a lower infection rate per leaf within mixed systems. We found varied nematode populations with monocultures hosting the highest root damage due to phytoparasitic nematodes. Weevil populations were also influenced by spatial arrangements with monocultures among the highest. Overall, mixed agroecosystems influence disease and pest incidence, potentially hindering pathogen spread. Plantain–cocoa associations reduce disease incidence in cocoa but may not affect the overall incidence of black sigatoka in plantain, at least during the establishment phase. Continued monitoring is crucial for understanding the long-term impacts and microclimatic effects on pest populations that could offer sustainable pest management strategies, reducing the reliance on chemical pesticides.

6 January 2025 in Siembra
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Journal Article
Open access
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JOJorge Eduardo Grijalva Olmedo
Jorge Eduardo Grijalva Olmedo
PMPaola Mercedes Palate Moreta
Paola Mercedes Palate Moreta
RVRoy Vera-Velez
Roy Vera-Velez
RVRaul Armando Ramos Veintimilla
Raul Armando Ramos Veintimilla
JTJean-François Tourrand
Jean-François Tourrand
APArnulfo Rigoberto Portilla
Arnulfo Rigoberto Portilla
In the Andean hillsides of Ecuador, indigenous populations use land mainly for grazing sheep and cattle. Animal response depends exclusively on the quality of forage and the soil’s physical and chemical conditions. The objective of this research was to evaluate two scenarios for intensifying pastures based on perennial ryegrass (Lolium perenne) and white clover (Trifolium repens), used at rest periods of 45- and 60 days in sites between 3,000-3,400 m a.s.l. used for grazing sheep and cows. These scenarios were compared with a natural grassland based on a plant community composed of Stipa ichu, Holcus lanatus, Rumex acetocella, and Paspalum sp., used in a traditional system with rest periods of 60-75 days in sites between 3,500-3,700 m a.s.l. in the Chimborazo River micro-watershed. Soil sampling was conducted at both sites to determine the soil fertility profile. Regarding the forage component, chemical composition, animal carrying capacity, milk production, and estimated enteric CH4 emissions were determined. In sheep serum, Ca, P, and Mg profiles, and the activity of AST, ALT, and FA enzymes were analyzed. The data were analyzed using ANOVA and Tukey 5% as a means comparison test. The results showed a better physicochemical property of the soil at the lower altitude. The intensification of pasture management and grazing through the utilization of rest periods of 45 days or less may represent a productive and low-emission option.

12 November 2025 in Diversity
Verified
Journal Article
Open access
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RVRoy Vera-Velez
Roy Vera-Velez
RVRaul Armando Ramos Veintimilla
Raul Armando Ramos Veintimilla
The biosphere is undergoing critical transformations due to deforestation, agricultural expansion, and logging, which have led to biodiversity loss, degradation of ecosystem services, and climate change. In tropical forests such as the Ecuadorian Amazon, these pressures are especially severe because reductions in forest cover compromise key ecological processes. The purpose of this article is to analyze the relationship between shifting agriculture, food security, and conservation in the Ecuadorian Amazon, with emphasis on the agroforestry system known as the chakra practiced by Kichwa communities. This model integrates crops such as cacao, maize, and cassava with native trees, without chemical inputs, and constitutes a practice that is both culturally significant and environmentally sustainable. Whereas conventional shifting agriculture tends to reduce soil fertility and the forest’s regenerative capacity, chakras maintain important levels of floristic diversity, favor the conservation of endemic species, and provide ecosystem services such as carbon sequestration and nutrient regulation. In this sense, chakras represent a resilient yet context-dependent agroforestry alternative that connects food security and sovereignty, biological conservation, income, Indigenous identity, and climate-change mitigation, although their long-term sustainability remains influenced by market forces, land-use pressure, and policy support in tropical contexts.

9 March 2023 in Protoplasma
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Journal Article
Closed access
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JCJ. Hugo Cota-Sánchez
J. Hugo Cota-Sánchez
DFDenver J. Falconer
Denver J. Falconer
OAOdair J. G. de Almeida
Odair J. G. de Almeida
JSJarvis A. Stobbs
Jarvis A. Stobbs
RVRoy Vera-Velez
Roy Vera-Velez
NBNicholas A. Belliveau
Nicholas A. Belliveau