Ramadhanil Pitopang

BIODIVERSITY INDICATOR GROUPS OF TROPICAL LAND-USE SYSTEMS: COMPARING PLANTS, BIRDS, AND INSECTS

Tropical landscapes are dominated by land-use systems, but their contribution to the conservation of biodiversity is largely unknown. Since changes in biodiversity in response to human impact are known to differ widely among taxonomic groups and guilds, there is a need for multidisciplinary collaboration of plant, vertebrate, and invertebrate experts. We used inventories of trees, understory plants, birds (subdivided into endemics, insectivores, frugivores/nectar feeders), butterflies (endemics, fruit feeders), and dung bee- tles in Sulawesi (Indonesia) to characterize a gradient from near-primary to secondary forests, agroforestry systems, and annual crops. As expected, overall species richness tended to decrease within this gradient of increasing habitat modification, but, in contrast to pre- vious studies, we found the species richness between most taxonomic groups to be signif- icantly correlated (36 out of 38 pairwise comparisons). However, on average only 48% of the variance could be explained (within the five main groups), and only a few taxonomic groups/guilds turned out to be good predictors for others: for example, trees for fruit- and nectar-feeding birds (88% explanation) and fruit-feeding butterflies (83%), endemic birds for endemic butterflies (72%), and frugivorous/nectar-feeding birds for fruit-feeding but- terflies (67%). Although biodiversity of land-use systems showed taxonomic group- and guild-specific differences, most groups were affected in a similar way by habitat modifi- cation. Near-primary forest sites proved to be of principal importance for conservation; however, land-use systems such as secondary forests (for understory plants, birds, and butterflies) and agroforestry systems (for butterflies) supported relatively high numbers of species and might play a significant role for biodiversity conservation in tropical landscapes.

Combining high biodiversity with high yields in tropical agroforests

Local and landscape-scale agricultural intensification is a major driver of global biodiversity loss. Controversially discussed solutions include wildlife-friendly farming or combining high-intensity farming with land-sparing for nature. Here, we integrate biodiversity and crop productivity data for smallholder cacao in Indonesia to exemplify for tropical agroforests that there is little relationship between yield and biodiversity under current management, opening substantial opportunities for wildlife-friendly management. Species richness of trees, fungi, invertebrates, and vertebrates did not decrease with yield. Moderate shade, adequate labor, and input level can be combined with a complex habitat structure to provide high biodiversity as well as high yields. Although livelihood impacts are held up as a major obstacle for wildlife-friendly farming in the tropics, our results suggest that in some situations, agroforests can be designed to optimize both biodiversity and crop production benefits without adding pressure to convert natural habitat to farmland.

Tree diversity in primary forest and different land use systems in Central Sulawesi, Indonesia

We studied the tree communities in primary forest and three different land use systems (forest gardens, ca. 5-year-old secondary forests, cacao plantations) at 900–1200 m elevation in the environs of Lore Lindu National Park, Central Sulawesi. The primary forests had ca. 150 tree species ≥10 cm diameter at breast height (dbh) per hectare, which is unusually high for forests at this elevation in southeast Asia. Basal area in the primary forest was 140 m2 ha−1, one of the highest values ever recorded in tropical forests worldwide. Tree species richness declined gradually from primary forest to forest gardens, secondary forests, and cacao plantations. This decline was paralleled by shifts in tree family composition, with Lauraceae, Meliaceae, and Euphorbiaceae being predominant in primary forests, Euphorbiaceae, Rubiaceae and Myristicaeae dominating in the forest gardens and Euphorbiaceae, Urticaceae, and Ulmaceae in the secondary forests. Cacao plantations were composed almost exclusively of cacao trees and two species of legume shade trees. Forest gardens further differed from primary forests by a much lower density of understorey trees, while secondary forests had fewer species of commercial interest. Comparative studies of birds and butterflies demonstrated parallel declines of species richness, showing the importance of trees in structuring tropical forest habitats and in providing resources.

Tree diversity in sub-montane and lower montane primary rain forests in Central Sulawesi

The tree diversity of sub-montane and lower montane primary forests is studied in plot-based inventories on two sites in Lore Lindu National Park, Central Sulawesi. Out of 166 species in total, 50 % are new records for Sulawesi (19 %) or the Central Sulawesi province (31 %). Species richness decreases with altitude. In the submontane forest, the highest Family Importance Values (FIV) are reached by the Lauraceae, Fagaceae, Sapotaceae, Moraceae and Euphorbiaceae. In the lower montane forest, the Fagaceae are of major importance (FIV 71.9), followed at some distance by the Myrtaceae, Elaeocarpaceae and Lauraceae. For each site, a group of important families is identified that is of minor importance or absent on the other site. The comparison of basal area (BA), number of species and FIV with published plot-based studies in sub-montane and lower montane primary forests in Malesia (Borneo, Sulawesi, Papua New Guinea) reveals: 1) with 35.4 and 37.1 m² ha-1, the BA is comparable to that measured in Borneo and Papua New Guinea, but does not support previous findings of extremely high BA in Sulawesi forests; 2) species richness is comparable to that in Borneo and other Sulawesi forests, but lower than in Papua New Guinea; 3) decrease in diversity with altitude is in accordance with findings in Borneo; 4) in sub-montane forests, the Lauraceae are generally important; the Sulawesi studies are closely related to those from Papua New Guinea; 5) the lower montane forests have the Fagaceae and Myrtaceae as most important families in common.

Can joint carbon and biodiversity management in tropical agroforestry landscapes be optimized

Managing ecosystems for carbon storage may also benefit biodiversity conservation, but such a potential ‘win-win’ scenario has not yet been assessed for tropical agroforestry landscapes. We measured above- and below-ground carbon stocks as well as the species richness of four groups of plants and eight of animals on 14 representative plots in Sulawesi, Indonesia, ranging from natural rainforest to cacao agroforests that have replaced former natural forest. The conversion of natural forests with carbon stocks of 227–362 Mg C ha−1 to agroforests with 82–211 Mg C ha−1 showed no relationships to overall biodiversity but led to a significant loss of forest-related species richness. We conclude that the conservation of the forest-related biodiversity, and to a lesser degree of carbon stocks, mainly depends on the preservation of natural forest habitats. In the three most carbon-rich agroforestry systems, carbon stocks were about 60% of those of natural forest, suggesting that 1.6 ha of optimally managed agroforest can contribute to the conservation of carbon stocks as much as 1 ha of natural forest. However, agroforestry systems had comparatively low biodiversity, and we found no evidence for a tight link between carbon storage and biodiversity. Yet, potential win-win agroforestry management solutions include combining high shade-tree quality which favours biodiversity with cacao-yield adapted shade levels.

Biodiversity patterns and trophic interactions in human-dominated tropical landscapes in Sulawesi (Indonesia): plants, arthropods and vertebrates

The need to capture primary production in order to sustain and improve economic livelihoods has lead to increasing conversion of natural habitat and intensification of agricultural practices in many parts of the world including most tropical regions. Understanding how these processes affect ecosystems and their functioning, in particular in the high-diversity ecosystems of the tropics, has become a key issue in ecological research. In this chapter, our focus is on the agriculture-forest landscapes of Central Sulawesi, Indonesia, an island widely known for its endemic yet still poorly known flora and fauna. The rise of the region to one of the largest cacao producing areas in the world is at the core of recent land-use change and intensification processes. Covering plants (trees, rattan palms, herbs, bryophytes) and several invertebrate (ants, dung beetles, cacao insect herbivores, fruit-feeding butterflies, parasitic Hymenoptera, spiders) and vertebrate groups (amphibians, birds, murids, reptiles), we give an in-depth overview of the determinants of biodiversity in cacao landscapes, including both management and landscape-scale variables into our analyses. Results show that shaded agroforests host a rich community of species. By adopting a large-scale study design we showed that proximity of natural forest is a key predictor for species richness of plants, invertebrates and vertebrates alike. Endemics and forest specialists benefit most from indigenous shade tree cover and proximity to natural forest. Importantly, several functionally important groups such as insectivorous and seed-dispersing birds benefit from tall shade trees, shade tree diversity and proximity to forest edge, while parasitoid diversity is greatest close to natural forests. Available data on the effects of landuse change in cacao landscape of Central Sulawesi is increasing. Change in landscape configuration and management practices are being clearly reflected in the composition of species communities, with likely impacts on ecosystem services such as pest control and pollination. More knowledge is needed especially in terms of species interactions and ecosystem functioning, but also on how existing knowledge can contribute to effective conservation in human-dominated landscapes outside protected areas.

Tree species diversity relative to human land uses in tropical rain forest margins in Central Sulawesi

The large-scale exploitation and conversion of tropical forests causes growing concern about the continued existence of the rich biodiversity of these forests. In the framework of the interdisciplinary STORMA project in Lore Lindu National Park area in Central Sulawesi, we studied tree diversity in six different land use types in the margins of submontane rain forest: undisturbed forest, forest with rattan extraction, selectively logged forest, cacao forest gardens, cacao plantations with mixed canopy of planted trees, and cacao plantations with a monospecific canopy. By analyzing such a finely subdivided use gradient it was attempted to answer the question how human usage and biodiversity conservation in the study area may be reconciled. Tree species (dbh > 10 cm) were sampled in 24 plots of 0.25 ha in all six land use types (4 replicates each). In total, 251 tree species (143 genera, 59 families) were recorded. Number of tree species per 0.25 ha was 51–63 in primary forest and gradually decreased towards the studied cacao systems. However, when native and cultivated tree species were considered separately, significant differences were detected among plantation types in terms of tree diversity. Tree endemism in forest plots totalled ca. 15% and was in good accordance with endemism in woody plants of Sulawesi. The number of endemic species was strongly reduced in cacao systems, although percentage endemism did not decline significantly in cacao forest gardens. Roughly one third of tree species in the forest plots were of economic importance as commercial timber trees; timber diversity was little affected by moderate human use of the forest but was significantly reduced in cacao forest gardens and dropped to near zero in other plantation types. The mean basal area of 57 m2 (36–80 m2) per ha in natural forest was lower than the previously recorded value from the study area but is still almost double as high as the mean value typical for tropical lowland forests in Southeast Asia.

Terrestrial herb communities of tropical submontane and tropical montane forests in Central Sulawesi, Indonesia

Although the diversity of terrestrial herbs is high tropical forests and although herbs may play important roles, e.g., as competitors of tree seedlings, most tropical botanical research to date has focused on trees. We studied the diversity, taxonomic composition, and biogeographical relationships of terrestrial forest herbs at two sites of tropical mountain forest at different elevations (Pono: 1000 m, Bariri: 1400 m) in Central Sulawesi. The study was conducted in 400 plots of 5 × 5 m2 (200 for each site). At Pono, we recorded 91 angiosperm herb species in 28 families, and 112 ferns and lycophytes in 15 families whereas at Bariri we found 77 angiosperms in 25 families and 94 ferns and lycophytes in 20 families. At both sites, the most species-rich angiosperm families were Araceae, Orchidaceae, and Zingiberaceae. The species numbers recorded by us are much higher than those reported in any previous tropical forest herb inventories and point to a previously underappreciated richness of plant assemblages on Sulawesi. Biogeographically, significantly more fern species reached their western than eastern distributional limits on Sulawesi, showing that the zoogeographical Wallaces line separating continental Asia and its shelf islands from the Moluccan region also holds for spore-dispersed plants.

Tree Composition in Secondary Forest of Lore Lindu National Park, Central Sulawesi, Indonesia

Indonesia is a country of megadiversity and ranks 5th on the list of the world’s richest countries in terms of biological diversity. The rich diversity of Indonesia is evidenced by the rain forests of Lore Lindu National Park (229,177 ha), Central Sulawesi, which may contain about 150 species of trees (> 10 cm dbh) in one hectare at ca. 1000 m elevation (Kessler et al. submitted). More than 2000 species of woody plants have been recorded from Sulawesi in a recent census (Kesler et al. 2002).

Uji Efektivitas Ekstrak Daun Kirinyuh (Chromolaena Odorata (L.) R. M. King Dan H. Rob) Sebagai Herbisida Alami Terhadap Perkecambahan Biji Kacang Hijau (Vigna Radiata (L.) R.Wilczek) Dan Biji Karuilei (Mimosa Invisa Mart. ex Colla)

Penelitian uji efektivitas daun kirinyuh ( chromolaena odorata (L.) R. M. King & H.Rob) sebagai herbisida alami terhadap perkecambahan biji kacang hijau ( Vigna radiata (L.) R. Wilczek) dan biji karuilei ( Mimosa invisa Mart. Ex Colla) dilaksanakan pada bulan Juli sampai September 2016, di Laboratorium Bioteknologi Jurusan Biologi Fakultas Matematika dan Ilmu Pengetahuan Alam, Universitas Tadulako. Penelitian ini disusun berdasarkan model Rancangan Acak Lengkap (RAL) terdiri dari 6 perlakuan dan 3 kali pengulangan dengan konsentrasi ekstrak P0 = 0% P1 = 15% P2 = 20% P3 = 25% P4 = 30% P5 = 35%. Variabel pengamatan meliputi daya kecambah (persentase perkecambahan), laju perkecambahan, panjang hipokotil dan berat basah. Hasil penelitian ini menunjukan bahwa pemberian ekstrak daun kirinyuh Chromolaena odorata berpengaruh dalam menghambat perkecambahan biji kacang hijau Vigna radiata dan biji karuilei Mimosa invisa . Pengambatan perkecambahan biji karuilei M . invisa dan kacang hijau V . radiata dimulai dari konsentrasi 15% sampai 35%. Hasil skrining fitokimia daun C . Odorata positif mengandung senyawa metabolit sekunder, yaitu saponin, tanin, flafonoid, alkaloid dan fenilok.