The geomorphologic forcing of wild boars

Abstract

Among the main invasive species, the wild boar (Sus scrofa) is the most responsible for soil degradation in Europe and many Italian regions. At the same time, the stable presence of this species in agricultural areas has induced a conflict with humans, causing economic losses, environmental degradation and also social issues. A clear quantification of the potential damages (in terms of soil bioturbation) of this species at large scale is, however, still obscure. The purpose of this research is to analyse the role of wild boars as a geomorphologic agent, presenting a general diagnostic framework regarding the geomorphic impact of this species, classifying and mapping potential sediment hotspots and their likely connection to rivers and road networks. Accordingly, a record of wild boar damage types is first presented, and their possible interaction with hydrological and geomorphological processes is described. Then, a pilot case study is discussed on mapping and quantifying wild boar damages in a hilly agricultural landscape located in northeast Italy. The wild boar damages were geolocalized using a geographical positioning system (GPS) in two years of intensive field campaigns among agricultural fields involved in wild boar damaging activities. For each damaged area (total 406), several measures of soil erosion depth were taken and the degradation surface of interest mapped for a total of 10 150 measures. The volume of removed soil was then estimated, considering the average depth of damages previously recorded. Finally, the Index of Connectivity was applied to provide a classification of the considered damages based on their connection to both river and road networks. The results indicate that the ongoing uncontrolled wild boar expansion may not affect crops only or be a risk for people, but can also increase soil erosion, with a potential connection to hydrographic networks and human infrastructures. © 2019 John Wiley & Sons, Ltd.

Estimating soil degradation in montane grasslands of North-eastern Italian Alps (Italy)

“…Nearly 1500 measures were collected using a simple meter stick. The measuring methodology is simple and is based on multiple depth measurements along transects at a variable distance in order to represent the depth variability of the surveyed area (see also Gudino-Elizondo et al., 2018; Mauri et al., 2019; Salesa et al., 2019 for further details and applications). In order to be more accurate, a metal bar helped to keep the meterstick perpendicular and also to represent the pre-erosion level (when placed across non-eroded spot) of the investigated surface.…”

“…With regards to zoogenic erosion, several animal species can concur on soil erosion with a large variability of activity. For example, we can have several typologies of erosion induced by grazing animals like deer (Kumbasli et al., 2010), tunnelling activities of mole-rats (Zuri and Terkel, 1997), exposure of soil particle by earthworms (Hazelhoff et al., 1981), erosion in riverbanks by Coypu ( Myocastor coypus ) (Sofia et al., 2017), and soil degradation due to wild boar ( Sus scrofa ) activity (Mauri et al., 2019).…”

Biogeomorphology, quo vadis? On processes, time, and space in biogeomorphology

“…Mauri et al . (2019) and Román‐Sánchez et al . (2019a, 2019b) employ new techniques in quantifying the contribution of biota on sediment transport.…”

“…At a larger scale, several efforts are aimed at investigating the effects of animal burrowing on sediment transport (e.g. Yoo et al, 2005;Haussmann, 2017;Mauri et al, 2019;Román-Sánchez et al, 2019a, 2019b. Vegetation is also at the heart of hillslope research, with studies exploring the effects of trees and plants on soils and geomorphology (e.g.…”

Wild boar recognition using convolutional neural networks

“…Wild boars spread diseases, 4 are a threat to native species, 5 and destroy natural habitats by destabilizing river banks, thus reducing water flow. In addition, they have become an economic problem as they are able to damage large crops 6 …”