Influence of soil and elevation on roadside cryptogam diversity in the tropical Andes

Background: The deforestation caused by road construction is one of the main drivers for both biodiversity and function loss in tropical ecosystems. Terricolous cryptogams are pioneers in colonizing roadside and they are limited by environmental and edaphic factors, thus, cryptogams may act as pioneers for ecosystem rehabilitation at roadside.Methods: This research was aimed at determining the diversity and composition of terricolous cryptogams, as well as their relationship with elevation and soil properties among roadside of the tropical Andes of Ecuador, in order to establish indicator species of this anthropized ecosystems. Five elevations were selected and in each one 50grids of 20 cm×30 cm were sampled(250 in total along the road), where occurrence, cover and identification of every cryptogam species were recorded. To evaluate the effect of elevation and soil properties on cryptogam richness, a linear model was conducted. Species composition among elevations was compared by non-metric multidimensional scaling(NMDS), and their relationship with the environmental variables through a correlation with adjusted axes was performed. A total of 72 species were recorded, those being 44 bryophytes and 28lichens. Species richness and composition of terricolous cryptogams were influenced by elevation and soil properties, thus the richness is higher at elevations E1, E2 and E3(2600, 2200 and 1800 m a.s.l.), differing from low elevations E4 and E5(1400 and 1000 m a.s.l.). Higher elevations with specific soil conditions(e.g bulk density, nitrogen and silt) harbored different cryptogam communities than those in lower elevations.Conclusions: A combination of both elevation and soil properties are shaping the colonization by terricolous cryptogams commnunities. As such, 18 species were identified as the best indicators for all sets of environmental conditions at the roadside, which can therefore be considered for monitoring ecological processes in tropical areas. Use of biocrusts for restoration is an emerging field. If implemented in the study region, elevation and soil drivers may help to better chose the more suitable cryptogam species to manage and stabilize roadside in tropical roads.

Conversion of Andean montane forest to exotic forest plantation modifies soil physicochemical properties in the buffer zone of Ecuador's Podocarpus National Park

Background:Andean montane forests(AMF)are biodiversity hotspots that provide fundamental hydrological services as well as carbon storage and sequestration.In recent decades,southern Ecuador AMFs have been seriously threatened by increased logging and conversion to forest plantations with exotic species.In this context,our main objective was to evaluate the effects of AMF conversion to forest plantations on soil physicochemical properties in the buffer zone(Bz)of the Podocarpus National Park(PNP),in southern Ecuador.For this purpose,random samples were taken at a depth of 0-10 cm in four plots in each contrast zone and analyzed for bulk density,porosity,textural class,leaf litter depth,soil pH,as well as the contents of organic matter(SOM),soil organic carbon(SOC),total nitrogen,and available phosphorus and potassium.Results:The results indicate that the conversion of AMFs produces an increase in bulk density and a decrease in SOM,SOC,and total nitrogen contents,thus modifying soil properties,which could result in a decrease in water regulation capacity and produce an increased risk of soil erosion.This accelerates degradation processes,as well as threatens shortages of the drinking water supply.Conclusions:This study can help decision-makers to implement soil management plans in the Bz of the PNP,based on the implementation of new regulations,where the conservation of AMF is promoted.In addition,it is recommended to apply environmental restoration strategies in the anthropized areas of the AMF,as well as in the areas with exotic eucalyptus and pine plantations.