Impact of Cropping Methods on Biodiversity in Coffee Agroecosystems in Sumatra, Indonesia

Cooperative management and its effects on shade tree diversity, soil properties and ecosystem services of coffee plantations in western El Salvador

“…These findings contradict Romero-Alvarado et al (2002), who found no correlations between shade tree density and diversity and soil nutrient content, pH levels or coffee yields. In contrast, Gillison et al (2004) found strong correlation between species richness and plant functional types (PFT) or guilds, and soil conditions. This seems in line with some of our results on the effects of tree density over certain soil properties (organic matter, total N, and pH and Mg concentrations), although we did not analyze community composition by guild or type.…”

“…An increasing number of investigations that have utilized this approach have provided important contributions to our understanding of the complex social and ecological context in which tropical shade coffee agroecosystems exist (e.g., Gillison et al 2004;Potvin et al 2005;Gordon et al 2007;Soto-Pinto et al 2007;Bacon et al 2008;Guadarrama-Zugasti 2008;Trujillo 2008). These integrated studies can provide useful information to guide policy makers and farmers in their efforts to develop shade coffee landscapes and institutional systems that adequately manage and conserve a variety of ecosystem services.…”

“…Our contradictory findings, concerning the effects of shade trees on soil properties, point to the need for further research in order to better understand the complex biophysical interactions occurring in these plantations. Important questions include: identifying optimal tree densities; teasing out the effects of species composition; and testing the use of plant functional types, as proposed by Gillison et al (2004). All of these variables need to be directly assessed in terms of coffee yield and the socioeconomic priorities of growers, in order to provide insight that can both inform research and prove useful to farmers.…”

“…Although we know from other systems that plant species composition can have significant impacts on availability and recycling of key nutrients in agroecosystems (Leblanc et al 2007;Redel et al 2007), and greater plant species diversity can increase nutrient use efficiency and reduce nutrient leaching (Tilman et al 1996;Schroth et al 2001), there has been little work on interactions between the agroecosystem properties of shade coffee systems and their collective impact on soil characteristics. A notable exception analyzed the effects of plant functional types (PFTs) and species assemblages on soil properties and other factors of coffee agroecosystems in Indonesia (Gillison et al 2004).…”

The impacts and opportunities of oil palm in Southeast Asia: What do we know and what do we need to know?

“…Not surprisingly, research demonstrates that the natural flora and fauna which occur in oil palm plantations are greatly impoverished when compared to lowland rainforests (e.g., PORIM 1994; Gillison 2002;Peh et al 2006) and even disturbed natural forest ( Figure 13; Fitzherbert et al 2008). Extensive field research carried out in oil palm frontier areas on the island of Sumatra has concluded that oil palm plantations result in a significant reduction in biodiversity if plantations replace natural forests, secondary forests, agroforests, or even degraded forests and scrubby unplanted areas (Gillison and Liswanti 1999;Maddox 2007). …”