Benefits of straw and pinus mulch as forest management practices in Mediterranean forests

Abstract

In semiarid conditions, re-vegetation programs are associated with a high level of sapling mortality. For the proper management of Mediterranean forest environments, alternative low cost afforestation methods that ensure the survival of seedlings and have minimal environmental impact are needed. One way to improve soil conditions is to apply organic amendments to the soil. This study assessed the effects of two types of organic mulching on the afforestation success of a degraded Mediterranean semiarid area. The soil treatments tested were: i) afforestation in soil amended with straw mulch (10 Mg ha-1); ii) afforestation in soil amended with mulch containing chipped branches of Aleppo Pine (Pinus halepensis Mill.) (10 Mg ha-1); iii) control plots with no amendments were used and considered as afforested in natural conditions. The afforestation plan was performed following the same species and pattern of plantation in each plot. We hypothesized that in the context of dry-Mediterranean climatic conditions the use of organic amendments would enhance plant establishment and ensure successful afforestation. The results showed that afforestation success increased when soils were amended with straw and pine tree mulch. The amendments had no effect on soil organic carbon. However, both treatments showed an increase in the average soil water content respect to the control conditions. Thus, the available water content in soils amended with mulch was higher than in the control during most of the duration of the experiment, and, consequently, there was less water stress following afforestation. This was well related with the increment in sapling survival rates founded in straw and pine mulch treatments.

Keywords

• reforestación
• acolchados orgánicos
• condiciones semiáridas
• agua útil
• suelos mediterráneos