Climate and soil factors influencing seedling recruitment of plant species used for dryland restoration

Abstract

Abstract. Land degradation affects 10-20 % of drylands globally. Intensive land use and management, largescale disturbances such as extractive operations, and global climate change, have contributed to degradation of these systems worldwide. Restoring these damaged environments is critical to improving ecosystem services and functions, conserve biodiversity, and contribute to climate resilience, food security, and landscape sustainability. Here, we present a case study on plant species of the mining intensive semi-arid Pilbara region in Western Australia that examines the effects of climate and soil factors on the restoration of drylands. We analysed the effects of a range of rainfall and temperature scenarios and the use of alternative soil materials on seedling recruitment of key native plant species from this area. Experimental studies were conducted in controlled environment facilities where conditions simulated those found in the Pilbara. Soil from topsoil (T) stockpiles and waste materials (W) from an active mine site were mixed at different proportions (100 % T, 100 % W, and two mixes of topsoil and waste at 50 : 50 and 25 : 75 ratios) and used as growth media. Our results showed that seedling recruitment was highly dependent on soil moisture and emergence was generally higher in the topsoil, which had the highest available water content. In general, responses to the climate scenarios differed significantly among the native species which suggest that future climate scenarios of increasing drought might affect not only seedling recruitment but also diversity and structure of native plant communities. The use of waste materials from mining operations as growth media could be an alternative to the limited topsoil. However, in the early stages of plant establishment successful seedling recruitment can be challenging in the absence of water. These limitations could be overcome by using soil amendments but the cost associated to these solutions at large landscape scales needs to be assessed and proven to be economically feasible.

Beneficios de los acolchados de paja y poda como prácticas para la gestión forestal de los montes mediterráneos

“…En los ambientes forestales, el patrón espacial y temporal de la vegetación dominante tendrá una clara influencia sobre las pérdidas de suelo por erosión hídrica, pues influye de dos maneras: (i) interfiriendo en la energía asociada a los procesos erosivos (Thornes, 1990;Cerdà, 2001); y (ii) modificando las propiedades físico-químicas de los suelos que la albergan (Thornes, 1990;Castillo et al, 1997;Muñoz-Rojas et al, 2016c). Así, durante la estación seca mediterránea, la falta de agua en la matriz del suelo se traduce en una reducción drástica de los inputs de SOC y, por tanto, a largo plazo, en la pérdida de fertilidad de los mismos (Van Wesemael y Veer, 1992;Fons y Vallejo, 1997;Martínez-Murillo et al, 2016a;Muñoz-Rojas et al, 2016a).…”

Effects of topsoil treatments on afforestation in a dry Mediterranean climate (southern Spain)

“…2). Several studies have shown that inadequate soil water storage is the major limiting factor for the sapling establishment in semiarid areas (Haase and Rose, 1993;Whisenant et al, 1999;South, 2000;HuesoGonzález et al, 2015;Muñoz-Rojas et al, 2016c), and others have reported new techniques needed to increase the AWC in dryland soils (Tongway and Ludwing, 1996;Shachak et al, 1998). Ros et al (2006) showed that the addition of amendments (urban organic waste, green waste, manure, and sewage sludge) favored the development of vegetation cover in Spain because of increased soil moisture.…”

“…Vegetation plays a fundamental role in soil conservation (Thornes, 1990;Castillo et al, 1997;Cerdà, 2001;Muñoz-Rojas et al, 2016c). In Mediterranean ecosystems, increasing forest cover has been considered a common technique for mitigating the effects of desertification (Nykvist, 1983;Vallejo et al, 2000;Le Honeuérou, 2000).…”

“…It is assumed that the risk of mortality declines when the period of transplantation stress is passed and physiological attributes return to normal levels (Maestre et al, 2003). Thus, the most important period during afforestation is that during which the plants adjust their morphology and physiology to the new environmental conditions (Maestre and Cortina, 2002a;Maestre et al, 2002bMaestre et al, , 2003Hueso-González et al, 2015;Muñoz-Rojas et al, 2016c).…”

“…All the environmental factors involved in afforestation processes must be taken into account in determining the responses of plants (Navarro and Palacios, 2004). Burdett (1990) considered that climatic conditions and soil parameters play key roles in the initial stages following transplantation during afforestation.…”