Conservation of newt guilds in an agricultural landscape of Belgium: the importance of aquatic and terrestrial habitats

Abstract

ABSTRACT1. Amphibians are declining worldwide in response to local and global pressures. Pond-breeding species are particularly vulnerable to environmental change because they rely on two components of the landscape: aquatic and terrestrial habitats. Agricultural practices are changing rapidly at world and local scales. As a consequence, farm ponds and their surrounding terrestrial landscapes will probably be affected.2. This study investigated the main habitat determinants for the occurrence of four species of newts (genus Triturus) inhabiting the Pays de Herve, a rural area in Belgium. Newt occurrence was determined for 258 ponds and the effect of habitat on distribution determinants was evaluated using generalized linear models.3. Newts were found in 42% of the ponds. Contrary to expectations, the distribution of newts was not positively associated with a high density of ponds. However, a low occurrence of newts and the low water depth of many ponds suggest a low quality of habitats. Proximity to forest, deep water, and an absence of fish in ponds are factors that significantly favour newts, but terrestrial habitat requirements vary among species.4. These results indicate the necessity of maintaining both forest and meadow patches in close proximity to ponds inhabited by newts, and of controlling fish introduction in those ponds. These findings stress the importance of conservation and management of terrestrial and aquatic habitats for maintaining amphibian diversity.

Conservation biology of the great crested newt in managed boreal forests in Finland

“…The decline has been linked to the loss and degradation of terrestrial and aquatic habitats (Stuart et al 2004, Beebee andGriffiths 2005), poor dispersal abilities (Sinsch 1990, Gibbs 1998, Kovar et al 2009), diseases, introduced species (Beebee and Griffiths 2005, Denoël and Lehmann 2006, Denoël and Ficetola 2008, high mortality rates in inhospitable terrains (Fahrig et al 1995, Carr and Fahrig 2001, Stevens et al 2006, Eigenbrod et al 2008, Cosentino et al 2011, and a fairly narrow tolerance of abiotic conditions (Semlitsch 2000, Houlahan andFindlay 2003) which also makes amphibians vulnerable to changes in terrestrial habitats.…”

“…In Europe, 59 % of amphibian species have declining populations, and nearly a quarter of amphibian species are considered threatened (Houlahan et al 2000, Denoël and Ficetola 2008, Temple and Cox 2009. The main drivers of the decline are habitat loss and degradation, as indicated by the fact that more than 60 % of freshwater habitats have an unfavorable conservation status in Europe (European Commission 2009, Temple andCox 2009).…”

“…This status calls for intensive research on the environmental factors that govern the distribution and abundance of newt populations, which is a prerequisite for effective conservation and management planning (Edgar and Bird 2006, Denoël and Ficetola 2008, Gustafson et al 2011. In Europe, the species is currently classed as critically endangered in the Czech Republic (Vlašín 2003), Austria (Gollmann 2007) and Belgium (Belgian Species List 2015), endangered in Finland (Terhivuo and Mannerkoski 2010), Switzerland (Schmidt and Zumbach 2005), Hungary (Vlašín 2003) and Slovakia (Vlašín 2003) and vulnerable in Norway (Dolmen 2010), Estonia (Red Data Book of Estonia 2008), the Netherlands (Creemers 2003) and Romania (Cogălniceanu and Rozylowicz 2015).…”

“…Although the great crested newt has been the subject of several studies (Edgar and Bird 2006, Karlsson et al 2007, Denoël and Ficetola 2008, Gustafson et al 2011, our knowledge of the species' habitat requirements is still incomplete. First, the majority of the studies have been conducted in Central and Western Europe, where the species occurs in a human-modified landscape that is affected by agricultural intensification, expansion of infrastructure and fish stocking (e.g.…”

“…First, the majority of the studies have been conducted in Central and Western Europe, where the species occurs in a human-modified landscape that is affected by agricultural intensification, expansion of infrastructure and fish stocking (e.g. Joly et al 2001, Edgar and Bird 2006, Denoël and Ficetola 2008. In these studies, the quality of forested vegetation on the surrounding breeding ponds has rarely been investigated in detail.…”