Highest Importance Value Index Research Articles

Population structure, vegetation composition and economic potentials of Parkia timoriana in Meru Betiri National Park, East Java, Indonesia

Abstract. Hidayati AN, Zuhud EAM, Andarwulan N. 2020. Population structure, vegetation composition and economic potentials of Parkia timoriana in Meru Betiri National Park, East Java, Indonesia. Biodiversitas 21: 203-210. Kedawung (Parkia timoriana (DC.) Merr.) is one of rare medicinal plant species because it is only found in a small part of Indonesia. P. timoriana has high ecological and economic potential because it contains various active compounds such as anticancer. This study was aimed to investigate the population structure, vegetation community composition, and distribution, as well as the potential production and economic values of P. timoriana in rehabilitation zone in Meru Betiri National Park, East Java, Indonesia. The methods used were vegetation analysis, direct observation, and in-depth interviews with selected respondents using purposive sampling. We found that P. timoriana population at the study sites was only at tree and pole stages, while no sapling and seedling was found. This condition implies that regeneration of P. timoriana at the study sites was not happening which can threaten its sustainability in the future. P. timoriana dominated the vegetation at the studied sites which were indicated by the highest importance value index. Utilization of P. timoriana by the local community was by selling the seeds to medicinal industries or used as herbal medicine. While having conservation values, the management of P. timoriana stands in Andongrejo Resort also had the potential to generate economic values up to 17.6 billion rupiahs. Considering the great economic potential of P. timoriana and to ensure sustainability, so that nursery, breeding and regeneration of P. timoriana should be made in order to obtain the best quality seeds.

Diversity of Herbaceous Plant in The Utilization Block of Sumber Agung Tahura Wan Abdul Rachman Bandar Lampung

Diversity is a variety of species that are similarly formed and the abundance of a species. The purpose of this study is to determine the diversity and characteristics of herbaceous plants in Sumber Agung Resort Bandar Lampung Wan Abdul Rachman (WAR) forest park. The method used is a purposive sampling method at several points, done by direct observation using the Belt Transect method with plot size 1x1 m² with a distance between plot 100 m² then the picture of herbaceous plants taken as documentation material. The species is then taken for identification regarding some literature. Data analysis by measuring the parameters of vegetation using the analysis of density and frequency variables which then determine the Importance Value Index (INP). Observation of herbaceous plants was done by identifying and making herbarium. The results of the study are, there are 45 species of herbaceous plants that have been identified, consisting of 22 families. The highest density of herbaceous species that are found belongs to Asteraceae, Solanaceae, Araceae, Poaceae, Zingiberaceae, and Euphorbiaceae. Characteristics of herbaceous growth are influenced by air temperature, soil moisture, and soil pH. The highest Important Value Index (INP) in herbaceous plants belongs to Family Poaceae; Lophatherium gracile with an important value index (INP) 31.43%.

The Community Structure of Microalgae and Exploring its Potentially to Biofuel Producing in Ranu Grati, East Java Indonesia

Microalgae are microscopic autotrophic organisms which act as one of the biofuel-producing organisms. Ranu Grati is one of the volcanic lakes located in Pasuruan, East Java. Human activities around the waters are responsible for eutrophication of the water quality. The aim of this study was (1) described the profile of water quality and microalgae community structure, and (2) investigated microalgae potential as a producer of biofuels based on lipid content. Explorative research was carried out by taking a sample of water at a depth of 50 cm at 5 stations. Water quality parameters measured were DO, pH, BOD, TP, and TKN. Microalgae samples were taken by filtering 3 L of water using Plankton Nets. Plankton samples were identified and calculated using Haemocytometer. Furthermore, microalgae abundance, Important Value Index (IVI), diversity index, richness taxa, Evenness, and Richness index were determined. Species with the two highest IVI was determined the lipid levels use literature. The results showed that the waters of Ranu Grati had been contaminated with high organic matter (BOD levels 8.30-8.72 mg/L) with trophic status classified as mesotrophic to hypertrophic (TP 0.05-0.08 mg/L and TKN 0.23-0.32 mg/L). DO levels was high and have a range value 7.47-9.87 mg / L, while range of pH value 8.73-9.07. There were found 18 species of microalgae with varied 10-18 species in each station. Pollution status of Ranu Grati based on Shannon Wiener diversity index categorized as moderately polluted with range values 1.95-2.34. Value of microalgae evenness 0.77-0.86 indicated high uniformity with equally even distribution of species. Chlorella sp. and Scenedesmus sp. have the highest IVI and have a potential to produce biofuel with lipid levels 28 -32% (dry weight) and 12-14% (dry weight) respectively.

Diversity of Herbaceous Plant in The Utilization Block of Sumber Agung Tahura Wan Abdul Rachman Bandar Lampung

Diversity is a variety of species that are similarly formed and the abundance of a species. The purpose of this study is to determine the diversity and characteristics of herbaceous plants in Sumber Agung Resort Bandar Lampung Wan Abdul Rachman (WAR) forest park. The method used is a purposive sampling method at several points, done by direct observation using the Belt Transect method with plot size 1x1 m² with a distance between plot 100 m² then the picture of herbaceous plants taken as documentation material. The species is then taken for identification regarding some literature. Data analysis by measuring the parameters of vegetation using the analysis of density and frequency variables which then determine the Importance Value Index (INP). Observation of herbaceous plants was done by identifying and making herbarium. The results of the study are, there are 45 species of herbaceous plants that have been identified, consisting of 22 families. The highest density of herbaceous species that are found belongs to Asteraceae, Solanaceae, Araceae, Poaceae, Zingiberaceae, and Euphorbiaceae. Characteristics of herbaceous growth are influenced by air temperature, soil moisture, and soil pH. The highest Important Value Index (INP) in herbaceous plants belongs to Family Poaceae; Lophatherium gracile with an important value index (INP) 31.43%.

Vegetation Structure and Composition on Rafflesia zollingeriana Habitat in Meru Betiri National Park

Meru Betiri National Park (TNMB) has five forest formation, e.g. coastal forest, mangrove forest, swamp forest, rheophyte, and lowland rain forest. The study aims to analyze vegetation structure and composition on Rafflesia zollingeriana habitat and to map the distribution of trees in TNMB. Vegetation data, diameter at breast height, and canopy height obtained by using line-transect method and analyzed using vegetation analysis. The sampling method used purposive sampling. TNMB had 64 trees species with 1,366 seedlings and saplings, 257 poles, and 183 trees. Pancal kidang (Aglaia variegata) had the highest Important Value Index (IVI) amounting to 32.46%. The result showed that the community similarity index (IS) in two sample plots was 86.86%. Tetrastigma spp. is a liana as a host of Rafflesia zollingeriana, and only found pancal kidang, besuleh, welangan, magnolia flower, laban, and rauh trees.

Analysis of vegetation diversity at Salib Kasih tourism area of Simorangkir Julu Village, North Tapanuli Regency

Salib Kasih tourism area is a prime religious tourism area in North Sumatra which is located in the forest area of Simorangkir Julu Village, North Tapanuli Regency. Structure and composition of vegetation in this area are not widely known, while Salagundi (Roudholia teysmanii) only found on this area. Generally, people only see pine as the main component of its plant. Studying the dynamics of a forest and its characteristics is an essential prerequisite for managing forests sustainability, especially for the sustainability of Salagundi which is native species of this area. This study aimed to obtain the information about the structure, composition, and diversity of plant in this area and as based data to maintain the existence of its species. The sampling technique was carried out by a combination method between the path method and the plot line. Vegetation analysis was carried out to gather information about the number and type of species at each growth level, Important Value Index (IVI) and Shannon Wienner Diversity Index. The results of the study found that there were seventeen species in this area. The number of each growth level was 691 at seedling levels, 671 at sapling levels, 209 at pole levels, and 224 at tree levels. The highest IVI at seedling, pole and tree level was Pinus merkusii (60.55; 87.58; 113.58), while at sapling level was Syzygium racemosum (50.00). The diversity index at seedling and tree level was low (1.95 and 1.76), while at sapling and pole level, it was classified as medium (2.07 and 2.08). According to the result, the existence of Salagundi needs to be preserved.

English

Wabero forest is one of the very few remnant moist evergreen montane forests in Southeast Ethiopia. However, basic data on vegetation structure and composition of the forest that could provide valuable information for possible conservation measures is lacking. The main objective of this study, therefore, was to investigate the woody species composition, vegetation structure and regeneration status of the forest. In the study 30 quadrants of 20 m by 20 m were used for woody species data and 5 m by 5 m for sapling and seedling in a nested form. The sample quadrants were laid down along transects at a distance of 300 m from each other. Diameters at breast height (DBH), basal area, frequency and importance value index were used for analysis of vegetation structure. In the study, a total of 47 woody plant species belonging to 43 genera and 33 families were recorded. The major families were Rubiaceae and Rutaceae each represented by four species followed by Sapindaceae, Moraceae and Oleaceae each represented by three species. The rest of the 28 families were represented by one or two species, only. The mean density of all the woody species recorded in the study site was 21,737 ha-1. Diospyros abyssinica, Podocarpus falcatus, Strychnos mitis, Celtis africana and Coffea arabica were found to be the most dominant and frequent species with the highest importance value index. Results of regeneration status of the forest, which was analyzed by comparing number of seedling and sapling with mature trees, revealed that the forest is under good regeneration status. Therefore, based on the results of the study, awareness creation and implementation of participatory forest management strategy is recommended in order to sustain the forest.   Key words: Basal area, diameters at breast height (DBH), importance value index, Montane forest, woody species composition.

Floristic composition in ecotone forests in northern Brazilian Amazonia: preliminary data.

BackgroundEcotone has been defined as “a multi-dimensional environmentally stochastic interaction zone between ecological systems with characteristics defined in space and time, and by the strength of the interaction” (Hufkens et al. 2009). This is a known concept to define transitional zones between two or more ecological communities, ecosystems or biotic regions. Ecotone forests, dispersed in northern Brazilian Amazonia, are natural formations which have been largely affected by anthropogenic impacts, such as deforestation and fire. Maracá Ecological Station, State of Roraima, Brazil, is a protected area with extensive representations of ecotone forests in this region of the Amazonia. Forest inventories and floristic surveys are important as they extend our knowledge (1) of forest structure and tree species composition and (2) of tree and palm species ecology in this region of the Amazonia. Both improve our ability to predict changes in plant diversity, considering the future scenarios of climate change in comparison with previous surveys performed in Maracá.New informationWe present a forest inventory carried out in 129 plots (10 m x 50 m; 6.45 ha in total) dispersed in a grid (5 km x 5 km) located in a forest zone ecotone in the eastern part of Maracá Ecological Station. All stems (tree + palm) with diameter at breast height ≥ 10 cm were recorded, identified and measured. A total of 3040 stems were recorded (tree = 2815; palm = 225), corresponding to 42 botanic families and 140 identified species. Seven families and 20 genera contained unidentified taxa (12.2%). Sapotaceae (735 stems; 10 species), Leguminosae (409; 24) and Rubiaceae (289; 12) were the most abundant families. Peltogyne gracilipes Ducke (Leguminosae), Pradosia surinamensis (Eyma) T.D.Penn. (Sapotaceae) and Ecclinusa guianensis Eyma (Sapotaceae) were the species with the highest importance value index (~ 25%). The dominance (m2 ha-1) of these species corresponds to > 36% of the total value observed in the forest inventory. Our dataset provides complementary floristic and structure information on tree and palm in Maracá, improving our knowledge of this Amazonian ecotone forest.

Identification of types and important value of aquatic vegetation and their potential to improve water quality in irigation canals of Mulyasari Village, Banyuasin District

Irrigation has an important role as a source of irrigating rice fields. Irrigation water is often contaminated by waste from anthropogenic activity. Indications of pollution in irrigation channels because the use of pesticides or other chemicals in agricultural land can be observed based on the number and type of vegetation that grows in the irrigation canal. Vegetation that grows in these waters is also believed to have the potential to improve the quality of water as phytoremediation. This study aims to determine the characteristics of vegetation, identify species that grow around the irrigation canals, and calculate the importance of aquatic and riparian vegetation in the irrigation channels of Mulyasari Village, Banyuasin Regency and analyze the potential of aquatic and riparian vegetation. to improve water quality. The method used to determine the station in this study is purposive sampling method. Vegetation analysis was carried out at 4 station points, research was conducted at low tide.. A bamboo quadrate plot having measurement of 1m x 1m with a perpendicular stake is used for data collection on aquatic vegetation, its type is observed and recorded. The results of the study found 6 types of vegetation, namely: Eleucharis dulcis, Hydrilla verticillata, Nymphae alba, Swersia hexandra Sw, Eleucharis acicularis, and Eleusine indica. Aquatic vegetation is dominated by flowering vegetation with linear leaf type. This study also shows that aquatic or riparian vegetation such as Eleucharis acicularis are the species that dominate canal waters with the highest Important Value Index is 46.51-81.22%, while Eleusine indica is a type of vegetation that tends to be rarely found (the average important value index is 10.86-19.84 %). Based on this, it was concluded that aquatic vegetation such as Eleucharis acicularis, which was found in the irrigation channel was the dominant vegetation in the canal. This vegetation has the potential as a phytoremidiation agent because of its role in maintaining the balance of the aquatic ecosystem so that it can improve the quality of water and can also be used as organic fertilizer, biofilter, and absorbent toxic elements. Eleucharis dulcis can improve the quality of water during the dry season by absorbing toxic dissolved ompounds.

Early natural regeneration patterns of woody species within gaps in a temperate secondary forest

Forest gaps are important small-scale disturbances that initiate forest succession. However, natural regeneration patterns within gaps remain unclear, especially in temperate secondary forests. In this study, three-dimensional graphic systems were established to show the whole regeneration patterns of woody species with different shade tolerance in natural gaps. Furthermore, all gaps were classified into three size classes, and each gap was divided into two parts, canopy gaps (CGs) and gap peripheries (GPs). A total of 34 woody species were found in the 41 surveyed gaps, but almost no tree species had a high importance value index (≥ 0.100). Total plant density decreased from the small gaps to the large gaps, showing a density trend similar to that of shade-tolerant species. Total species richness peaked in the medium gaps, which indicated that medium gaps could provide moderate environments for most woody species. Both the species richness and plant density of shade-tolerant species were lower in CGs than in GPs, regardless of gap sizes. In contrast, both the species richness and plant density of shade-intolerant species were higher in CGs than in GPs. Interestingly, intermediate shade-tolerant species exhibited a “doughnut” regeneration pattern in the large gaps, which indicated that they could neither compete with shade-intolerant species in CGs nor invade GPs occupied by shade-tolerant species. Our findings suggest that gap formation could benefit woody species regeneration, but subsequent treatments based on gap silviculture are needed to eliminate low-value species and manage target tree species, which would help accelerate the restoration of secondary forests.

Status and distribution of Red Panda (Ailurus fulgens fulgens) in Simsime community forest of Papung VDC of Taplejung district, Nepal

Red Panda (Ailurus fulgens fulgens), globally an endangered species of Himalaya, were studied in Simsime community forest of Papung Village Development Committee (VDC) in Taplejung district. It was carried out to assess status, habitat characteristics and threats to Red Panda. Three transects were laid out along the contours and their total length was 2200 m. The altitude of these transects varied from 2800–3400m. While moving along the transect line, the signs such as pellets, footprints and nests of Red Panda were searched and the GPS points were recorded in those places where the signs were observed. The habitat was assessed simultaneously to describe its characteristics in this community forest. Square plots of 10m * 10m, 4m * 4m and 1m*1m were laid out to assess trees, shrubs and herbs, respectively along contour lines at an altitudinal interval of 200 m between 2800 m and 3400 m and the plots were spaced at a distance of 100 m. Diameter at breast height (DBH) of major tree species (Juniperus spp., Pinus spp., Acer spp. and Rhododendron spp) was measured in the plots. The signs were found in Simsime community forest at an altitude of 3026 m, 3125 m and 3127 m. Overall sign encounter rate for this community forest was 1.36/km. Acer spp. had the highest Importance Value Index (IVI) and Arundinaria malingers the major bamboo species with highest relative frequency (RF). Based on direct field observation, major threats to Red Panda were found to be grazing and bamboo cutting in which majority of the respondents agreed.

Assessing Forest Structure and Composition along the Altitudinal Gradient in the State of Sikkim, Eastern Himalayas, India

Understanding the structure and composition of native forests is a prerequisite in developing an adaptive forest management plan for Himalayan forest ecosystems where climate change is rapid. However, basic information on forest structure and composition are still limited in many places of the Eastern Himalayas. In this study, we aimed to understand the diversity, structure, and composition of forests and their variations along an altitudinal gradient in Himalayan forests. The study was conducted in the Indian federal state of Sikkim, Eastern Himalayas. We carried out a comprehensive and comparative evaluation of species diversity, stand basal area, and stem density along the altitudinal gradient from 900 m a.s.l. to 3200 m a.s.l. We used stratified random sampling to survey eighty-three plots each 0.1 ha in forest communities that occurred along the altitudinal gradient: (a) lower (900–1700 m) altitude forest (N = 24), (b) mid (1700–2500 m) altitude forests (N = 37), and (c) higher (2500–3200 m)altitude forests (N = 22). We measured and identified all living trees with a >3 cm diameter at breast height in each plot. We counted 10,344 individual plants, representing 114 woody species belonging to 42 families and 75 genera. The family Fagaceae and its species Lithocarpus pachyphyllus (Kurz) Rehder. were reported as the most dominant forest trees with the highest Importance Value Index. The Shannon diversity index was recorded as being the highest for the low-altitude forests, whereas measures of structural diversity varied among forests along with altitude: the mid-altitude forests recorded the highest stem density and the high-altitude forests showed the highest mean stem DBH (diameter at 1.3 m height). One significant finding of our study was the disparity of the size class distribution among forests along the altitudinal gradient. Overall, we found a reverse J-shape distribution of tree diameter signifying the uneven-agedness. However, we showed, for the first time, a complete lack of large trees (>93 cm DBH) in the lower altitude forests. Our study highlights conservation concerns for the low-altitude forests that record high species diversity, although lacked large-diameter trees. We anticipate that our study will provide a comprehensive understanding of forest diversity, composition, and structure along the altitudinal gradient to design conservation and sustainable management strategies

Tree Species Diversity, Richness and Similarity in Disturbed and Undisturbed Forest of Ketambe Research Station, Southeast Aceh regency

Tree species richness in disturbed and undisturbed site of Ketambe Research Station Ketambe, Southeast Aceh regency, Indonesia has been studied from March to May 2018. Research sites were determined using purpossive sampling method. Tree samples were recorded within a plot measuring 400 m2 for each sites with a total of 40 plots. Ecological parameters measured in this study were: Density (D), Relative density (RD), Frequency (F), Relative frequency (RF), Dominance (Do), Relative dominance (RDo), Importance Value Index (IVI), Shannon’s diversity index (H’), Margalefs index (R1), and Evenness (E). Estimation of biomass (B) carbon stock (CS) was conducted using allometric equation. Physico-chemical characteristics measured were: air temperature (°C), soil acidity (pH), light intensity (lx), air humidity (%), total organic N (%), and phosphate quantity (ppm) as secondary data. Our study found 79 tree species belonging to 30 families, 61 species in undisturbed site and 47 species in disturbed site. An important species with the highest Importance Value Index (IVI) was Dysoxylum sp.3 in undisturbed site and Macaranga tanarius in disturbed site. The biodiversity was more diverse in undisturbed site (H’ = 3.70; R1 = 10.93) than disturbed site on the whole study area (H’ = 3.47; R1 = 9.10). The values of evenness (E) varied between 0.66–0.68 among sites. Estimation of tree biomass and carbon stock followed the similar trend with a total of B = 971.299 Mg/ha and CS = 485.649 Mg/ha on the whole study area. The present study revealed that some vital tree species exist in forest area of Ketambe Research Station as carbon sinks along with their high biodiversities from both disturbed and undisturbed regions. The information on tree species diversity may provide a baseline information for conservation of the biodiversity in this area.

Floristic Composition, Distribution, and Association of Pandanus (Pandanaceae) in Bukit Duabelas National Park Jambi

Pandanus species is widely distributed over Bukit Duabelas National Park in Jambi. Suku Anak Dalam (SAD), a local community living in Bukit Duabelas National Park area, use the natural fibers from Pandanus for many necessities, such as plaiting, building materials, and performing mytological rituals. This study aimed to examine floristic composition, distribution patterns, and association of pandanus species in Bukit Duabelas National Park. Sampling was conducted using a striped line, with a plot of 35 sample plots. Dominance of species was calculated using dominant type of important Value Index (IVI) based on the density, frequency, and dominance of sample plot enumeration. Distribution patterns was analyzed using the Morisita Index, while association patterns were measured by Contingency tables and Chi-square tests. Floristic composition was mostly found in the seedling strata consisting of 106 species. The species with highest important value index (IVI=14.53) was Palaquium gutta. There were two species of Pandanus (Benstonea kurzii and Benstonea atrocarpa) were spread in groups and three species of pandanus (Pandanus labyrinthicus, Pandanus furcatus, and Pandanus immersus) were spread evenly. The pandanus species found was associated with Benstonea kurzii was Litsea sp1. This present study suggested that the conservation of pandanus species should be conducted as a piece of rehabilitation of tropical forests in Bukit Duabelas National Park.

Structure of The Treelets and Shrub Vegetation in Tropical Sub-Mountain Forest of Mount Salak Bogor, West Jawa, Indonesia

We study the structure, indicator species and diversity of treelets and shrubs vegetation in tropical sub-mountain forests of Mount Salak Bogor, West Java. There were 4 vegetation groups at Bray-Curtis distance 0.6 - 0.8, namely groups 1, 2, 3, and 4, each consist of 13 plots, 17 plots, 8 plots, and 22 plots. One way Permanova test shows that the vegetation group is different in terms of structure and composition of vegetation. Dicranopteris dichotoma (Thunb.) Bernh., Athyrium sorzogonense (Presl.) Milde., and Cinchona officinalis L., are the species with the highest Important Value Index in all plots. Indicator species are not found in group 2. There are 8 combined vegetation groups that have indicator species. The one-way Kruskal-Wallis test shows the difference in Shannon-Wienner diversity index (H’) (Kruskal-Wallis χ2 = 20.541, df = 3, p-value = 0.0001311 ), Simpson’s index (D) (Kruskal-Wallis χ2 = 23.855, df = 3, p-value = 2.678e-05), Pielou’s evenness index (J’) (Kruskal-Wallis χ2 = 14.315, df = 3, p-value = 0.002506) and Species Richness (S) (Kruskal-Wallis χ2 = 17.868, df = 3, p-value = 0.0004683) among vegetation groups. Post hoc test with Games Howel shows group 2 and 4 have differences in all parameters of diversity. The values of H’, D, and S between group 1 and 4 are different. The difference in S values also appears between group 3 and 4.

Population structure of Cotylelobium melanoxylon within vegetation community in Bona Lumban Forest, Central Tapanuli, North Sumatra, Indonesia

Abstract. Susilowati A, Rachmat HH, Elfiati D, Kholibrina CR, Kusuma YS, Siregar H. 2019. Population structure of Cotylelobium melanoxylon within vegetation community in Bona Lumban Forest, Central Tapanuli, North Sumatra, Indonesia. Biodiversitas 20: 1681-1687. In many forests stand, Cotylelobium melanoxylon is hard to find in the wild at present day because its bark has been intensively harvested for traditional alcoholic drink and sold by kilogram in traditional market in North Sumatra and Riau. This activity has put the species into serious threats of their existence in their natural habitat. We conducted study to determine the population structure of the species at seedling to tree stage in Bona Lumban Forest, Central Tapanuli. We used purposive sampling by making line transect at forest area where C. melanoxylon naturally grow. There were four transects with each transect consisted of five plots in which nested plots were established to record data at four growth stages, resulting in 80 plots in total. The result showed that the Important Value Index (IVI) for C. melanoxylon were 66.33, 17.65, 11.82, 12.90; Diversity Index (H) were 2.9, 1.90,2.88, 2.53 and 12.90, Index of evenness (E) were 0.844, 0.534, 0.85, 0.935 and the Index of Richness (R) were 5.71, 7.13, 5.37, 3.67 for the stage tree, pole, sapling, and seedlings, respectively This result demonstrates that C. melanoxylon still grows naturally in Bona Lumban at all stages from tree to seedling. However, there might be a problem in its natural regeneration as there is big difference of its high IVI at tree stage compared to IVI value for its younger stages. The regeneration status of C. melanoxylon was also classified into fair. This might be generated from the condition that the existing mature trees remaining were no longer productive and healthy due to excessive harvesting for its bark.

Searching for potential wood biomass for green energy feedstock: A study in tropical swamp-peat forest of Kutai Kertanegara, Indonesia

Abstract. Amirta R, Haqiqi MT, Saparwadi, Septia E, Mujiasih D, Setiawan KA, Sekedang MA, Yuliansyah, Wijaya A, Setiyono B, Suwinarti W. 2019. Searching for potential wood biomass for green energy feedstock: A study in tropical swamp-peat forest of Kutai Kertanegara, Indonesia. Biodiversitas 20: 1516-1523. Recently, much attention has been focused on finding suitable plant species, from different forest ecosystems, having the potential to be used as sources of renewable energy. Most of such information was reported from the lowland forest area and only limited information is available regarding swamp-peat forest species, including their energy potency. Therefore, in this paper, plant diversity and energy potency of swamp-peat forest wood biomass were studied to reveal their potential as green energy feedstock. Physico-chemical characterization of wood biomass was performed using the American Society for Testing and Material (ASTM) protocols. Twenty-seven species of plants, consisting of 23 trees and 4 shrubs, belonging to 19 families were identified, amongst which Shorea balangeran had the highest importance value index (87.72%). The results showed that T. obovata exhibit the highest suitability to be used as energy feedstock indicated by the highest energy production of 4.60 MWh per ton of dry biomass, followed by L. indica (4.56 MWh/ton), D. excelsa (5.52 MWh/ton), F. rukam (4.20 MWh/ton), P. galeata (3.66 MWh/ton), S. caudatilimbum (3.61 MWh/ton), A. elmeri (3.59 MWh/ton), G. nervosa (3.49 MWh/ton) and G. bancana (3.42 MWh/ton). The high density of wood species correlated with the high value of energy potency. In contrast, the fast-growing tree and shrub species, such as K. hospita (1.76 MWh/ton), C. odorata (1.36 MWh/ton) and O. sumatrana (1.17 MWh/ton), showed lower energy potency. The most dominant plant species, S. balangeran gave only 2.96 MWh energy per ton of dry biomass and it was classified in the middle group of plant species suitable as green energy feedstock, along with other species, such as C. brachiata, C. rotundatus, P. javanicum, V. umbonata, L. speciosa, V. pinnata, and A. longifolius. Due to suitable energy properties, growth rate and also adaptability of this woody biomass, they can be exploited to support sustainable supply of biomass feedstock for the green electricity program in the study area.

Weeds community structure on the rice field (Oryza sativa L.) in bulusari village, Sayung district, Demak regency

Rice weeds are disturbing plants that grow together with rice and otherwise well-controlled, it will reduce the quantity and quality of crops. The aim of this research is to analyze the community structure of weed rice in 8-week-old. Benefits of this research are expected to provide information about the types of rice weeds and their characteristics. Research was conducted in June 2018 in Bulusari Village, Sayung District, Demak Regency; and Ecology and Biosystematics Laboratory, Biology Departement, Diponegoro University. Method of this research is a random sampling method used a plot sized 1 m x 1 m as many as 18 plots. Results of the research were the highest Important Value Index is Echinochloa colonum (L) Link species and rice weed diversity index is low.

The Composition and Important Value Index of Trees for Wildlife Feed in Bacan Island, South Halmahera

Forests provide protection, food, and habitats for wild animals such as monkeys, birds, bats, squirrels, and weasels that depend on the fruits and seeds from the trees. Due to human’s activities, the functions of the forest in Bacan Island have decreased significantly in terms of numbers, kinds, and important value index. Local people have conversed forests into agricultural lands. As a result, the existence of natural resources especially trees, which supply nutrients for wild animals such as monkeys, birds, bats, squirrels and weasels, is being threatened. The current study aimed to investigate the composition and important value index of every type of plants used for wildlife feed. An inventory method was employed in plots of 20 m × 20 m for tree-level observation. This method would be useful to obtain the list of plant composition for wildlife feed and to determine some vegetation parameters including the density, domination, frequency, and important value index of the plants. This research showed that Duobanga moluccana, Drancontomelon dao, Bacacaurea anguilata Merr, Theobroma cacao, Mangifera indica, Canarium casferum, Myristica fatua and Myristica sperciosa are the composition of plants that could supply nutrients for the wild animals. The highest important value index (IVI) (52.78%) was observed in Drancontomelon dao. Medium IVI which ranged from (31.47-44.42%) was reported by Duobanga moluccana, Bacacaurea anguilata Merr, Theobroma cacao, Canarium casferum, Myristica fatua and Myristica sperciosa. Meanwhile, the lowest IVI (29.52%) was found in Mangifera indica.

KEANEKARAGAMAN JENIS VEGETASI TINGKAT POHON DI HUTAN ADAT GUNUNG SOKA DUSUN PADANG SEBATIK KECAMATAN AIR BESAR KABUPATEN LANDAK

Forest is an ecosystem unit in the form of a stretch of land containing biological natural resourcesdominated by trees in its natural environment which can not be separated from the life of indigineous communities. This study aims to find out the diversity of vegetation types of stand composition trees in Gunung Soka Indigenous Forest. This study used transect method and the transect lineswere determined purposively. There were 4 (four) transect lines with 500 m lenght, 10 m wide to the left and 10 m wide to the right. The observation plot was 20 m, and there were 25 plots, so the total was 1 ha. There were 100 plots to study with 4 transect line so the total area was 4 ha. The result show that there are 23 trees vegetation consists of 13 family, 741 of individual trees in Gunung Soka Indigenous Forest. The highest important value index (INP) was found in engkabang bukit (Shorea pinanga Scheff.) with a value of 82,25, while the lowest important value index was found in keraci (Quercus lucida Roxb.) with a value of 1,42. The Dominance index (C) of trees vegetation is 0,17525 or C = 1 ,which shows that there are more than one dominant tree. The Diversity index (DS) of trees vegetation is closte to 1, which shows moderate diversity of species. The Highest species Abundance index (e) of tree vegetation was found in line 1 with a value of 0,9493, meanwhile the lowest value was found in line 2 with a value of 0,5764.Kata Kunci : Diversity,indigenous forest, tree vegetation