Effectiveness of Dung Beetles as Bioindicators of Environmental Changes in Land-use Gradient in Sulawesi, Indonesia

Bioindicators have been widely accepted as useful tools for monitoring and detecting changes in the environment or habitat condition. By using bioindicators, it is possible to assess the impact of human activities on the biota, instead of examining the entire biota. In this paper we analyzed diversity of dung beetles (Coleoptera: Scarabaeidae) across land use gradient inCentral Sulawesi and tested the suitability of dung beetles as bioindicators for environmental changes. Ninety baited pitfall trapswere placed and several habitat parameterswere measured at five land-use types ranging from natural forest to cacao agroforestry systems to open areas in 2009 and 2012. The effectiveness of dung beetles as bioindicators of environmental changes was evaluated by the IndVal method, a method combining the specificity and fidelity of certain species with particular types of habitat or environmental conditions. Surprisingly, the results showed that the diversity of dung beetles in two types of cacao plantations were similar to the forest sites and were significantly higher than the open cultivated area. Of the 16 dung beetles species analyzed only four species could be suggested as indicator (characteristic) species while the majority of collected species were categorized as detector species. Two of them (Copris saundersi and Onthophagus forsteni) were associated with natural forest and cacao agroforestry system, thus were suggested as the indicator of shaded and cooler habitats whereas O. limbatus and O. trituber can be suggested as indicator of unshaded and warmer habitats (bare land area).Keywords: bioindicators, diversity, Scarabaeidae, habitat preferences, IndVal

Kajian Jenis Pengorok Daun (Liriomyza SP.) (Diptera: Agromizydae) pada Berbagai Tanaman Inang di Lembah Palu

Hama pengorok daun merupakan hama pendatang dari benua Amerika Latin yang masuk ke Indonesia sekitar tahun 90 an dan dilaporkan keberadaannya di Palu, Sulawesi Tengah sekitar tahun 2005. Hama ini memiliki banyak tanaman inang atau bersifat polifagus. Tujuan penelitian adalah untuk mengetahui jenis-jenis pengorok daun pada berbagai tanaman inang di Lembah Palu. Penelitian di laksanakan di Kelurahan Boyaoge, Kelurahan Pengawu (Kecamatan Palu Barat) dan Desa Langaleso (Kecamatan Dolo) dan di Laboratorium Hama dan penyakit tumbuhan Fakultas Pertanian Universitas Tadulako yang berlangsung pada bulan Juli sampai Oktober tahun 2012. Karakter morfologi yang diamati adalah warna scutellum, pola warna tergit pada abdomen dan warna tungkai. Selain itu, diamati juga ciri serangan Liriomyza pada tanaman inangnya. Berdasarkan hasil identifikasi yang telah di lakukan di Laboratorium didapatkan 5 (lima) spesies lalat penggorok daun, yakni Liriomyza brassicae pada tanaman Sawi; Tomat dan Kembang kol, Liriomyza bryonae pada tanaman Sawi, Liriomyza chinensis pada tanaman Bayam, Liriomyza huidobrensis pada tanaman Kacang Panjang dan Liriomyza sativae pada tanaman Tomat dan Kemangi. Kelima spesies Liriomyza tersebut selain berbeda secara morfologi juga menunjukkan ciri serangan yang berbeda pada tanaman inangnya

Effectiveness of Dung Beetles as Bioindicators of Environmental Changes in Land-use Gradient in Sulawesi, Indonesia

Bioindicators have been widely accepted as useful tools for monitoring and detecting changes in the environment or habitat condition. By using bioindicators, it is possible to assess the impact of human activities on the biota, instead of examining the entire biota. In this paper we analyzed diversity of dung beetles (Coleoptera: Scarabaeidae) across land use gradient inCentral Sulawesi and tested the suitability of dung beetles as bioindicators for environmental changes. Ninety baited pitfall trapswere placed and several habitat parameterswere measured at five land-use types ranging from natural forest to cacao agroforestry systems to open areas in 2009 and 2012. The effectiveness of dung beetles as bioindicators of environmental changes was evaluated by the IndVal method, a method combining the specificity and fidelity of certain species with particular types of habitat or environmental conditions. Surprisingly, the results showed that the diversity of dung beetles in two types of cacao plantations were similar to the forest sites and were significantly higher than the open cultivated area. Of the 16 dung beetles species analyzed only four species could be suggested as indicator (characteristic) species while the majority of collected species were categorized as detector species. Two of them (Copris saundersi and Onthophagus forsteni) were associated with natural forest and cacao agroforestry system, thus were suggested as the indicator of shaded and cooler habitats whereas O. limbatus and O. trituber can be suggested as indicator of unshaded and warmer habitats (bare land area)

Diversity of arthropods and decreased seed weight for various cocoa plantation systems

Cocoa farmers in Palolo sub-district conducted cocoa cultivation by implementing three cocoa cropping systems, including the cocoa cropping system without using shade trees (A1), using a number of permanent shade trees (A2), and using natural forests as the shade trees (A3). The aim of the study was to determine the diversity of arthropods and decreased seed weight in the three cocoa cultivation systems. The sampling of arthropods used pitfall traps, light trap, and Yellow Fan Trap. The found 2684 arthropod individuals represented 12 orders, 47 families and 106 species. Diversity index and abundance index were the highest for cocoa crop ecosystem A2 (2.9 and 13.1). The largest decrease in weight of cocoa seeds was found in the A1 locations (8.34%) and the lowest in the A3 locations (3.61%). We recommend that cocoa cultivation should use protective trees

Bird observation and sampling in tropical agroforestry landscapes of the Napu Valley in Central Sulawesi, Indonesia

We investigated the local bird community in Central Sulawesi (Indonesia), with focus on insectivorous species in the agroforestry landscapes adjacent to the Lore Lindu National Park. All study sites were situated at the northern tip of Napu Valley in Central Sulawesi, Indonesia. After an initial mapping of the study area, we selected 15 smallholder cacao plantations as sites for our study in March 2010. These sides were mainly used for bird and bat exclosure experiments. All sited were situated along a local gradient (shade availability on each plantation) and a landscape gradient (distance to primary forest), which were independent from each other. In September 2010 and from February until June 2011, we assessed the bird community on our 15 study sites using monthly point count and mist netting sampling. Point count (20 minutes between 07 am and 10 am and in between the net checking hours) and mist netting surveys (12 hours, between 05:30 am and 17:30 pm) were conducted simultaneously but only once per month on each study site, to avoid habituation of the local bird community to our surveys. Further, point counts were conducted at least 100 m apart from the mist netting sites, to avoid potential disturbance between the two methods. We discarded all observations beyond 50 m (including those individuals that flew over the canopy) from the statistical analysis, as well as recaptures of individuals within identical mist netting rounds

Bird predation experiments in tropical agroforestry landscapes of the Napu Valley in Central Sulawesi, Indonesia

We performed bird predation experiments (dummy experiments), using artificial prey and bird community data to investigate the importance of predator diversity vs. predator identity in cacao agroforestry landscapes. All sample sites were situated at the northern tip of Napu Valley in Central Sulawesi, Indonesia. After an initial mapping of the study area, we selected 15 smallholder cacao plantations as sites for our exclosure experiments in March 2010. For our predation experiment, we selected 10 (out of 15) study sites and 5 cacao trees per site for the application of artificial prey for birds (dummy caterpillars made of plasticine). Our study trees (numbered from 1 to 5 per site) were randomly chosen and we kept spacing of at least two unmanipulated cacao trees between two study trees to avoid clumped distribution. To quantify both daytime/diurnal predation and night-time/nocturnal predation (e.g. birds vs. bats), we applied 7 caterpillar dummies on all study trees and controlled them for predation marks in the early morning (05:00-06:00 am), in the evening (17:00-18:00 pm) and in the early morning on the next day (completing one survey round). In total, we performed four survey rounds per study site (in June and July 2011). The caterpillar dummies were always applied in the same order and on three different parts of each cacao study tree: One 'control dummy' (located on first branching of the cacao tree); 3 'branch dummies' (located on one main branch coming from first branching; 20-25 cm between single dummies) and 3 'leaf dummies' (3 medium aged cacao trees adjacent to main branch were selected and single dummies placed in the center of each cacao leaf). The different positions were chosen to control for different foraging modes of predators (e.g. branch gleaners versus leaf gleaners). During day- and nighttime surveys, we controlled if the dummy caterpillars were still present in their original position, if they were absent and could not be relocated on the ground or if they were fallen to the ground, but could still be recorded. Eaten dummies were counted as 1 mark usually, except for those dummies, where two or more different kind of arthropods had eaten parts of the dummy (2 marks or more). Other predation marks were added to this number. For each dummy, we counted the total number of different predation marks. We focused on predation marks that could be identified with certainty (based on preliminary observations and/or literature): marks of birds, rodents and snails. Finally, we analysed the relationship of bird predation marks and bird community parameters (abundance vs. diversity), as well as effects of local and landscape management on the avian predation success

The amphibians and reptiles of the Lore Lindu National Park area, Central Sulawesi, Indonesia

Thomas Cherico Wanger, Iris Motzke, Shahabuddin Saleh and Djoko T. Iskandarhttp://www.salamandra-journal.com/index.php?option=com_docman&Itemid=7

Avian species identity and predation success in tropical cacao agroforestry of the Napu Valley in Central Sulawesi, Indonesia

Avian ecosystem services such as the suppression of pests are considered being of high ecological and economic importance in a range of ecosystems, especially in tropical agroforestry. But how bird predation success is related to the diversity and composition of the bird community, as well as local and landscape factors, is poorly understood. The author quantified arthropod predation in relation to the identity and diversity of insectivorous birds, using experimental exposure of artificial, caterpillar-like prey on smallholder cacao agroforestry systems, differing in local shade management and distance to primary forest. The bird community was assessed using both mist netting (targeting on active understory insectivores) and point count (higher completeness of species inventories) sampling. The study was conducted in a land use dominated area in Central Sulawesi, Indonesia, adjacent to the Lore Lindu National Park. We selected 15 smallholder cacao plantations as sites for bird and bat exclosure experiments in March 2010. Until July 2011, we recorded several data in this study area, including the bird community data, cacao tree data and bird predation experiments that are presented here. We found that avian predation success can be driven by single and abundant insectivorous species, rather than by overall bird species richness. Forest proximity was important for enhancing the density of this key species, but did also promote bird species richness. The availability of local shade trees had no effects on the local bird community or avian predation success. Our findings are both of economical as well as ecological interest because the conservation of nearby forest remnants will likely benefit human needs and biodiversity conservation alike

Avian species identity drives predation success in tropical cacao agroforestry

Avian ecosystem services such as the suppression of pests are considered to be of high ecological and economic importance in a range of ecosystems, especially in tropical agroforestry. However, how bird predation success is related to the diversity and composition of the bird community, as well as local and landscape factors, is poorly understood. We quantified arthropod predation in relation to the identity and diversity of insectivorous birds using experimental exposure of artificial, caterpillar-like prey in 15 smallholder cacao agroforestry systems differing in local shade-tree management and distance to primary forest. The bird community was assessed using both mist-netting (targeting active understorey insectivores) and point counts (higher completeness of species inventories). Bird predation was not related to local shade-tree management or overall bird species diversity, but to the activity of insectivorous bird species and the proximity to primary forest. Insectivore activity was best predicted by mist-netting-based data, not by point counts. We identified the abundant Indonesian endemic lemon-bellied white-eye Zosterops chloris as the main driver of predation on artificial prey.Synthesis and applications. The suppression of arthropods is a major ecosystem service provided by insectivorous birds in agricultural systems world-wide, potentially reducing herbivore damage on plants and increasing yields. Our results show that avian predation success can be driven by single and abundant insectivorous species, rather than by overall bird species richness. Forest proximity was important for enhancing the density of this key species, but did also promote bird species richness. Hence, our findings are both of economical as well as ecological interest because the conservation of nearby forest remnants will likely benefit human needs and biodiversity conservation alike. The suppression of arthropods is a major ecosystem service provided by insectivorous birds in agricultural systems world-wide, potentially reducing herbivore damage on plants and increasing yields. Our results show that avian predation success can be driven by single and abundant insectivorous species, rather than by overall bird species richness. Forest proximity was important for enhancing the density of this key species, but did also promote bird species richness. Hence, our findings are both of economical as well as ecological interest because the conservation of nearby forest remnants will likely benefit human needs and biodiversity conservation alike