An Analysis of Forest Restoration 120 Years after Reforestation on Badlands in the Southwestern Alps

Abstract

We report the results of descriptive and functional analyses of a representative forest and watershed in the southwestern Alps, where the Forest Service has attempted reforestation of badlands for erosion control since 1860, relying on the non-native Pinus nigra ssp. nigra (Austrian black pine). One hundred twenty years after the first tree plantings, the plant communities are still early seral assemblages for the most part, with Austrian black pine occurring alone in the canopy. In contrast, most of the marly soils have physically recovered part of their total depth, with layers of fragmented and altered material equal to 50 cm, but their structure and chemical fertility is still poor. Autogenic soil restoration is proceeding however, largely engineered by earthworms (up to 49 individuals and 27 g/m 2 ). Two dominant species are presumed keystone: Lumbricus terrestris and Octolasion cyaneum (Lumbricidae). The reestablishment of indigenous tree species is apparently not inhibited by site fertility or lack of nearby seed pools. We hypothesize that ex-cessive stand density is responsible for the poor regeneration because it discourages the birds and rodents that control seed dissemination. Mortality of pines due to infestation by Viscum album subsp. austriacum (mistletoe) is creating large openings and should be specially managed. One hundred twenty years after the first plantings, the nineteenth-century vision that restoration of badlands was ecologically feasible is validated, as is the strategy to establish pioneer tree species. Here Austrian black pine acts as a nurse stand and enables the return of indigenous broad-leaved trees and a wide array of herbaceous species as well. However, our results clearly indicate that appropriate silvicultural tactics should now consist of tree thinning to promote the true restoration of native biodiversity and ecosystem functions.

Responses of soil moisture in different land cover types to rainfall events in a re-vegetation catchment area of the Loess Plateau, China

“…One of the most pressing tasks of this project involves the recovery of the vegetation because of its crucial role in soil conservation (Wei et al, 2012). Re-vegetation can result in the increase of vegetation cover (Xin et al, 2008), improvement of soil nutrient levels (Zhou et al, 2008) and recovery of soil physical properties (Vallauri et al, 2002). However, re-vegetation also aggravated water scarcity (Wang et al, 2011a), which was one of the most prominent issues related to sustainable development.…”

Catchment based hydrology under post farmland abandonment scenarios

“…Many mountainous areas of the Mediterranean region have undergone natural revegetation of former agricultural land along with extensive afforestation programs by national forest services to improve the use of abandoned land as a resource and to control hydrological and soil erosion processes (Ortigosa et al, 1990;Vallauri et al, 2002). Because few studies to date have assessed the implications of these programs on hydrological response (Richard and Mathys, 1999;Chirino et al, 2001;Piégay et al, 2004), it remains unclear whether the hydrology of an afforested area is comparable to that of a natural forest, with differences in soil and forest canopy properties.…”

Governance of Land Use Planning to Reduce Fire Risk to Homes Mediterranean France and California

“…Demographic shifts from rural to urban areas after World War II led to the abandonment of farmland and the expansion of forests into formerly cultivated areas. Aggressive reforestation efforts also shifted degraded farmland and pastures to trees [38,39].…”

“…Demographic shifts from rural to urban areas after World War II led to the abandonment of farmland and the expansion of forests into formerly cultivated areas. Aggressive reforestation efforts also shifted degraded farmland and pastures to trees [38,39]. As a result, 38% of the southern French landscape (including 15 Mediterranean departments) 1 is now forested, most of which is young forest less than 60 years old (Figure 1a).…”