Shrubland management in Northwestern Patagonia: an evaluation of its shortterm effects on multiple ecosystem services

Abstract

Sustainable management of natural resources is one of the greatest challenges that humanity is facing today. Part of the global energy demand is supplied by woody biomass whose production needs to ensure the maintenance of structures and functions that forests provide through biodiversity and ecosystem services. The general objective of this chapter is to review the effects of shrubland management for woody fuel production on biodiversity and different ecosystem services (ES) in northwestern Patagonia shrublands. This revision is based on results obtained from a field experiment evaluating a harvesting intensity gradient in three contrasting site qualities. Regrowth biomass production increases with harvesting intensity, and increments are higher at the high- and medium-quality sites. Consequently, the highest extraction intensity is the selected alternative for firewood production as economic metrics indicate. Wood energy density of shrubland species is higher than that observed in other woody species commonly used as fuels, highlighting the potential for energy supply in these ecosystems. Effect of harvesting on biodiversity varies with site quality: it is negative at the low-quality site and positive at the high-quality site, and biodiversity is maximized at intermediate harvesting intensity at the medium-quality site. Regarding the fire protection ES, the effects are general: firewood harvesting reduces both fuel continuity and live fuel moisture content at all three sites. Litter cover, associated with soil formation ES, also decreases with harvesting intensity in all the sites, but the size effect depends on both site quality and time since intervention. When integrating the multiple ES, it is concluded that northwestern Patagonia shrublands could provide bioenergy ensuring biodiversity and ES, but the optimal level of intervention will depend on site conditions and decision-maker’s preferences.