Biology subjects

Dangles, O.

Publications and source records attributed to Dangles, O..

2 recordsLinked to original sources

bioRxiv2024

Community density patterns estimated by species distribution modeling: the case study of an insect virus interaction

O_LITime delays complicates the analysis of trophic dependence, which requires large time series data to study local associations. C_LIO_LIHere we propose using species distribution modeling. This approach removes confounding time lag effects and allows using data obtained separately in the different species. C_LIO_LISince the approach is correlative, it cannot be interpreted in terms of causality. C_LIO_LIWe apply the method to the interaction between the invasive potato moth Tecia solanivora and its granulovirus PhoGV in the Northern Andes. Host density was analyzed based on 1206 pheromone trap data from 106 sampled sites in Ecuador, Colombia and Venezuela. Virus prevalence was evaluated in 15 localities from 3 regions in Ecuador and Colombia. glm models were optimized for both variables on bioclimatic variables. Predicted virus prevalence was not significantly correlated to host density in the sampled virus sites. Across the climatic range covered by the study, correlation was R=-0.053. Of the total population of insect in this range, 26% were expected to be infected. C_LIO_LIInfection status was also analyzed for spatial structure at different scales: storage bag, storage room, field, locality, country. Locality and storage bag explained respectively 8% and 26% of the total deviance in infection status in glm analysis. Field and storage structure differed within locality but not always in the same direction. C_LIO_LIThis basic method may help studying statistical relationships between species density across a number of trophic models making use of existing non sympatric data, with none or limited additional sampling effort. C_LI

ecology↗

bioRxiv2020

The response of culturally important plants to experimental warming and grazing in Pakistan Himalayas

The response of wild plants towards climate warming is taxa specific, but overgrazing could also be a determining factor for the alpine ecosystems. Overgrazing and climate warming are important drivers of alpine grassland degradation worldwide. Local indigenous peoples will be the first impacted by such degradation due to impacts on animal production and the availability of local medicinal plants. Studies on plant responses to overgrazing and climate change are rarely performed to assess threats to these biological and cultural systems. Long-term observations or manipulative experiments are promising, but rarely use strategies to evaluate the sensitivity and vulnerability of such ecosystems to climatic change. We studied the combined effects of overgrazing and increased temperatures on culturally important medicinal plants of Khunjerab National Park, Pakistan. Three experimental treatments were used (control, warming through an open-top chamber, and exclusion of grazing animals vs. the control). These experimental plots were installed at different elevations (3352-4969 m) and were monitored routinely. Grazing reduced vegetation cover & biomass by 2.3% and 6.26%, respectively, but that was not significant due to the high variability among study plots. However, warming significantly increased the overall percentage cover and biomass of all target plant species, ranging from 1{+/-}0.6% in Bistorta officinalis to 18.7 {+/-} 4.9% in Poa alpina. Thus, warming may increase the availability of therapeutic plants for indigenous people while overgrazing would have deteriorating effects locally. This research illustrates that vegetation sensitivity to warming and overgrazing is likely to affect man- environment relationships, and traditional knowledge on a regional scale.

ecology↗