Environmental indicators reflective of road design in a forested landscape

Abstract

Abstract. Roads cause both chemical and physical disturbance at the time of creation and through the maintenance of the road. However, none have fully considered the extent of above-and below-ground impacts related to roads. Our study seeks to fill this gap with three objectives: (1) quantify differences in the nematode community by road-use intensity, (2) estimate distance of environmental impact of roads using nematode community indices, and (3) relate nematode communities to abiotic soil and aboveground plant communities for a relatively comprehensive environmental assessment of the spatial footprint of roads on the landscape. Soil and plant samples were co-located at six distances from the road edge (shoulder, sideslope, ditch, backslope, 10 m from forest edge, and 50 m from road crown) for each of 10 transects perpendicular to each of three road types (highways, two-lane paved, and gravel). There were differences in all nematode community measures based upon distance as a main effect, correlating with patterns of plant communities. Nematode community index values reflect increased disturbance closer to the road, particularly at the shoulder, with later ecological succession and a shift in the decomposer food web with increased distance from the road and in reference forest sites. In contrast, chemical properties of soil were influenced more by road type and the two-way interaction of road type and topography. Salt concentrations were greatest by two-lane paved roads, while heavy metal concentrations were greatest near highway roads. This study is one of the most comprehensive assessments of environmental impact by roads, providing data for accurate transportation system models. The results suggest that conscious design and management of the forest buffer and intentional inclusion of a ditch as a roadside feature may minimize pollutant movement and protect surrounding landscapes.

Soil Nematode Fauna and Microbial Characteristics in an Early-Successional Forest Ecosystem

“…Significant correlations were identified using a Monte Carlo permutation test between the two resemblance matrices. Our approach was modelled after the application of the CoCA to identify associations between the plant communities and the soil microbial communities [47] and between the plant communities and the soil nematode communities [48]. All multivariate analyses were performed using CANOCO (version 5.04) [49].…”

“…Areas damaged by windstorms are usually cleared; disturbed stands are harvested for economic (recouping financial losses before wood quality deteriorates) and sanitary (damaged trees can attract insects that can attack undisturbed trees in their neighborhood) reasons. Removal of the forest canopy dramatically alters the site microclimate, mainly light and water conditions [3], that lead to changes in the composition, diversity, and habitat structure of understory plant species, which have potential implications for the soil biota [48]. Any disturbance of the soil will lead to a succession in bacteria and fungi and the associated food web, with an initial decrease and then an increase in biodiversity [50], in agreement with the authors of Reference [16] who found that the characteristics of microbial activity (basal respiration, microbial biomass, N mineralization, and catalase activity) were significantly lower in the acidic soil of a cleared site of a Lariceto-Piceetum coniferous forest immediately after a windstorm.…”

Análisis de indicadores ambientales espacio-temporales de agua, suelo y vegetación

“…Investigaciones recientes muestran que los indicadores ambientales presentan datos y comparaciones útiles para contribuir en la sostenibilidad de la naturaleza, en la toma de decisiones y formulación de políticas ambientales (Alphan, 2017;Neher et al, 2017;Nowak y Schneider, 2017;Pratama et al, 2017) y constituyen una herramienta básica de información y seguimiento de los procesos que se originan en el medio natural, social y económico (Xu y Zhang, 2013;Asumadu-Sarkodie y Owusu, 2017;Sinha et al, 2017).…”

“…Los indicadores ambientales dan seguimiento al impacto ambiental biofísico y socioeconómico, reconocidos como una necesidad fundamental a nivel local, regional, nacional e incluso internacional (Neher et al, 2017;Sinha et al, 2017). Evalúa el impacto ambiental mediante herramientas innovadoras y precisas para predecir las consecuencias del desarrollo (Klug y Kmoch, 2015;Arnaiz-Schmitz et al, 2017;Han et al, 2017) proporcionando información útil para la planificación al presentar datos y comparaciones actualizados (Alphan, 2017;Gao et al, 2017;Luo et al, 2017;Bao y Zou, 2018).…”

“…Con base a lo anterior, se determinó que los indicadores ambientales son herramientas básicas de información y seguimiento de procesos que se dan en el medio natural, social y económico, para conocer el estado y la tendencia de los recursos naturales (Xu y Zhang, 2013;Asumadu-Sarkodie y Owusu, 2017;Sinha et al, 2017). Además, proporcionan información de forma sencilla y fácil de entender estadísticamente; a través, de un modelo o conjunto de supuestos que relacionan el indicador con fenómenos más complejos (Walz, 2015;Neher et al, 2017) comunicando información científica y técnica sustentada en la problemática ambiental (Schindler et al, 2015;Turner et al, 2016).…”