Soil nutrient fluxes and vegetation changes on molehills

Abstract

Abstract. The hypothesis that mole burrowing activity alters soil nutrient fluxes and that, as a response to the new conditions, a specialized guild of species develops on the molehills, was tested in an area located in the southwestern Spanish Pyrenees, on a spectrum of montane grassland communities that varies from xeric to temporally waterlogged. Evidence for an association between disturbance and nutrient availability was reported for nitrogen. Mole‐disturbed soils had elevated amounts of inorganic nitrogen compared to soils in surrounding pastures. At the first stages of mound revegetation, changes in nitrate flushes and in species competitive relationships following disturbance appeared to facilitate the establishment of ruderal and non‐mycorrhizal species. The diversity of the whole grassland was enhanced by the existence of these sets of species, abundant on mounds and rarer in the pasture. However, the difference was mainly quantitative, as exclusive colonizers of molehills were not found.

Plant Colonizers Shape Early N-dynamics in Gopher-mounds

“…In Europe, species from the same genera flourish in bare, nutrient-enriched soils, such as molehills and decline sharply at later stages of the revegetation process (Bonis et al, 1997;Canals and Sebastia`, 2000). The behavior of Cerastium and Aphanes is consistent with that of fugitive nutritional colonizers, taking advantage of the flush of available N released in recently disturbed areas to develop rapidly and produce seeds before being replaced by more N-efficient species (Grime, 1977;Redente et al, 1992).…”

“…In a species-rich grassland, disturbances may favor some plant species over others. Plant species that colonize disturbed areas are often nondominant and non-competitive species in undisturbed sites (Bonis et al, 1997, Canals andSebastia`, 2000). These species can rapidly make use of the resources released by disturbance (space, light, N) to develop and reproduce before being out-competed.…”

Burrowing by badgers (Meles meles) and foxes (Vulpes vulpes) changes soil conditions and vegetation in a European temperate forest

“…Locally, they cause the release of different resources such as nutrients, light and water (Goszczyn´ska and Goszczyn´ski 1977;Hobbs and Mooney 1985;Wilson and Tilman 1993;Huntly and Reichman 1994;Canals and Sebastia´2000;Kerley et al 2004;Borchard et al 2008), and reduce interspecific competition, allowing new species to establish (Wilson and Tilman 1993;Kinlaw 1999;Kyle et al 2007). On the landscape scale they add to habitat patchiness (heterogeneity), and in consequence boost species diversity (Veen and Olff 2011).…”

Quantification of landform heterogeneity and its relationship with ecological patterns in broad-scale post-mine rehabilitation

“…In response to a hurricane-like disturbance, the micro-topographic variability generated by the uprooting of trees facilitated germination and growth of vegetation (Carlton and Bazzaz, 1998) and species richness (Elliott et al, 2002) similar to restoration experiments that used pit-and-mound design as a tool to facilitate restoration, discussed previously in this chapter. These disturbances change the nutritional conditions of soils and direct the plant community structure (Canals and Sebastià, 2000) thereby increasing the diversity of plant species as well as that of microsite conditions (Gigon and Leutert, 1996).…”

“…For example, moisture holding capacity of soil, soil organic matter or soilnutrient availability are often used as indicators to assess the initiation of ecological processes (Swanson et al, 1988, Odeh et al, 1991, Zak et al, 1991, Canals and Sebastià, 2000, Hook and Burke, 2000, Sharma et al, 2000, Takyu et al, 2003, Sebastiá, 2004, Barka et al, 2011, Ott and van Aarde, 2014. Different indices that have capacity to inform about the recovery of complex ecological processes have been used in the past to indicate more advanced rehabilitation status.…”