Soil indicators to assess the effectiveness of restoration strategies in dryland ecosystems

Abstract

Abstract. Soil indicators may be used for assessing both land suitability for restoration and the effectiveness of restoration strategies in restoring ecosystem functioning and services. In this review paper, several soil indicators, which can be used to assess the effectiveness of ecological restoration strategies in dryland ecosystems at different spatial and temporal scales, are discussed. The selected indicators represent the different viewpoints of pedology, ecology, hydrology, and land management. Two overall outcomes stem from the review. (i) The success of restoration projects relies on a proper understanding of their ecology, namely the relationships between soil, plants, hydrology, climate, and land management at different scales, which are particularly complex due to the heterogeneous pattern of ecosystems functioning in drylands.(ii) The selection of the most suitable soil indicators follows a clear identification of the different and sometimes competing ecosystem services that the project is aimed at restoring.

Combined deep sampling and mass-based approaches to assess soil carbon and nitrogen losses due to land-use changes in karst area of southwestern China

“…Globally, the large-scale conversions of natural ecosystems to croplands and other managed ecosystems have already resulted in historically large emissions of C into the atmosphere (as higher as 320 Pg C), since the dawn of settled agriculture (Lal, 2010). In turn, land degradation due to soil organic C (SOC) loss may damage ecosystem services and functions Costantini et al, 2016;Foley et al, 2005), directly affecting the hydrological and biogeochemical cycles in the earth system García-Díaz et al, 2016;Sonneveld et al, 2016). Thus, the changes in quality and quantity of SOC may inevitably influence the soil degradation, agricultural productivity and food security (Carter, 2002;Janzen, 2015;Srinivasarao et al, 2014).…”

Fallow Reduces Soil Losses and Increases Carbon Stock in Caatinga

“…Tang et al (2016) observed that areas with larger aboveground biomass have higher aggregate stability which has correlation with erosion-related variables, especially soil erodibility (Stanchi et al, 2016). The observed reduction of ΔOC and increased land cover may be an indication of an increase in the carbon stock in H F , which improved soil's physical conditions such as aggregate stability, infiltration, porosity and water storage capacity (Stanchi et al, 2016;Costantini et al, 2016).…”

“…However, studies have found that the time analyzed was not enough to allow the recovery of degraded lands (Manzano & Návar, 2000). Fallow is only effective on the long term (Costantini et al, 2016). According to Príncipe et al (2014), a period of at least 30 years is necessary for natural forests regenerate in semi-arid areas.…”

“…In cultivated and grazed areas, fallow is the oldest and least expensive land management practice for promoting environmental recovery and regeneration of vegetation, soil and fauna over the long term (Sousa et al, 2012;Mekuria & Aynekulu, 2013;Costantini et al, 2016). This management consists of reclamation of degraded land by means of resilience of the soil and vegetation alone.…”

“…This management consists of reclamation of degraded land by means of resilience of the soil and vegetation alone. The main indicators used to assess the restoration of a given area are organic matter, physical and chemical characteristics of the soil, water infiltration, soil and nutrient loss, soil compaction, vegetation, and patterns of succession in different semi-arid regions of the world (Manzano & Návar, 2000;Costantini et al, 2016;Tang et al, 2016). In the Brazilian semi-arid region, studies in degraded areas usually focus on soil loss and runoff (Medeiros & Araújo, 2014), but there are few studies reporting nutrient transportation (Freitas et al, 2013) and the necessary time period for soil restoration in degraded areas of Caatinga (Sousa et al, 2012).…”