Conservation Value of Cacao Agroforestry Systems for Terrestrial Herbaceous Species in Central Sulawesi, Indonesia Daniele Cicuzza 1 and Michael Kessler Institute of Systematic Botany, Zollikerstrasse 908008, University of Zurich, Switzerland Yann Clough Agroecology Institute, G ¨ ottingen University, Waldweg 26 D-37073 G ¨ ottingen, Germany Ramadhanil Pitopang Department of Biology, Tadulako University, 94118 Palu, Sulawesi, Indonesia Daniela Leitner Department of Landscape Ecology, Goldschmidtstrasse 5 D-37077, G ¨ ottingen University, Germany and Sri S. Tjitrosoedirdjo Department of Biology, Jl. Raya Darmaga Kampus IPB Darmaga Bogor 16680, Bogor Agricultural University, Indonesia ABSTRACT Tropical secondary forest and agroforestry systems have been identified as important refuges for the local species diversity of birds and other animal groups, but little is known about the importance of these systems for terrestrial herbs. In particular, few studies report how the conversion from tropical forest to technified cacao plan- tation affects the species richness and the community structure of herbs. We conducted surveys in 43 cacao plantations along the border of the Lore Lindu National Park in Central Sulawesi, ranging from agroforests to technified cacao, categorizing the plantations as rustic cacao, planted shade cacao, and technified cacao. We recorded 91 herb species. Of the 74 species determined to species level, 21 were also found in natural forests, while 53 were recorded only in agricultural habitats. Araceae was the most forest-dependent plant family while Asteraceae included the highest number of nonforest species. Overall, the presence of forest species was confined to moderately intensively managed rustic and planted shaded plantations. Distance from the forest, which has been identified as a crucial parameter for the diversity and composition of other taxa in cacao agroforests, only played a minimal role for herbs. Our study suggests that native forest herbs maybe more vulnerable to forest conversion than animal groups. The intensification of cacao plantation management increases the presence of weedy species to the detriment of native forest species. Key words: cacao; Sulawesi; terrestrial herbs; tropical forest. IN THE FACE OF ONGOING TROPICAL FOREST DESTRUCTION AND DEGRA- DATION, secondary forests and agroforestry systems are becoming increasingly important habitats for tropical biodiversity (Perfecto & Vandermeer 2008). Cacao and coffee plantations, in particular, of- ten retain a tall canopy of mixed tree species and are therefore con- sidered to structurally resemble natural forests to some degree, providing important habitats for birds (Sodhi et al. 2005, Clough et al. 2009), amphibians and reptiles (Wanger et al. 2009), bats (Faria et al. 2006), bryophytes (Ariyanti et al. 2008), and trees (Zapfack et al. 2002, Sambuichi & Haridasan 2007). Different an- imal and plant groups, however, react differently to habitat factors and are therefore represented idiosyncratically in agroforestry sys- tems (Steffan-Dewenter et al. 2007, Kessler et al. 2009). A full assessment of the conservation potential of agroforestry systems thus needs to account for as many taxonomic and ecological groups as possible. Ground-living herbaceous plants have largely been ignored in biodiversity assessments of agroforestry systems, even though herbs can make up a considerable proportion of plant diversity in tropical forests (Gentry & Emmons 1987) and also provide food or struc- tural habitats for a wide range of animals (Bos et al. 2007b, H¨ ohn et al. 2009, Wanger et al. 2009). Furthermore, herbs may act as direct competitors to cultivated plants and act as reservoirs for pathogens and herbivores (Entwistle 1972, Siebert 2002). To our knowledge, herbs in cacao agroforestry systems have only been cur- sorily studied in Brazil (Faria et al. 2007), Cameroon (Bobo et al. 2006), and Indonesia (Steffan-Dewenter et al. 2007, Ramadhanil et al. 2008). These studies have shown that the abundance and di- versity of terrestrial herbs is often higher in agroforestry systems than in natural forests. Many herbaceous plants in agricultural sys- tems, however, are widespread, weedy, and often alien species (Backer 1973), and the conservation value of agroforestry systems to native species is unknown. The importance of flowering herba- ceous plants has not been explicitly studied in cacao plantations, though their importance for increasing the presence and diversity of Received 18 March 2010; revision accepted 24 October 2010. 1 Corresponding author; e-mail: daniele.cicuzza@systbot.uzh.ch BIOTROPICA 43(6): 755–762 2011 10.1111/j.1744-7429.2010.00741.x r 2011 The Author(s) 755 Journal compilation r 2011 by The Association for Tropical Biology and Conservation