Highest Importance Value Index Research Articles

The structure and diversity of vegetation treelets of tropical mountain forest on mount Bawakaraeng

The study about the diversity and structure of treelet vegetation in three slope areas on the mountainous forest of mount Bawakaraeng, Regency of Gowa, Province of South Sulawesi had been done. There were 17 species of treelets throughout the study area, from 13 families and 16 genera. The Asteraceae family has the highest number of species with 3 species, followed by Fabaceae and Solanaceae which each has 2 species. Pteridium aquilinum, Chromolaena odorata, Breynia oblongifolia, and Pogostemon cablin are the species with the highest important value index. The number of treelet species ranges from 15-16. Treelet species were mostly found in the flat slope area. The Shannon-Wiener diversity index (H’) ranges from 2,033-2,161 and was found to be highest on steep slopes and lowest on flat slopes. The H’ has the same tendency as Simpson’s Diversity Index and Evenness Index of Pielou (E) and reverse relationship with Simpson’s Dominance Index.

Plant diversity in agroforestry system and its traditional use by three different ethnics in Central Sulawesi Indonesia

This paper discusses the result of the study on plant diversity in the Agroforestry system and its traditional uses by the three different ethnicities in Banggai Regency, Central Sulawesi, Indonesia. The basic data of traditional plants used by each of the ethnic groups in the research site wer collected through an in-depth interview initiated by an informed consent using a questionnaire containing open-ended questions—fifty (50) respondents from each of the ethnic groups representing different jobs. The result showed that the highest number of plant species was found in research site B, bu the highest number of individual plants was noted in research site A. The highest Important Value Index (IVI) of tree, poles, sapling a,nd seedling level of plant species differed among the three research sites. When viewed from the perspective of traditional plant use, the highest ICS of plants utilized by the three ethnics was “coconut” (Cocos Nucifera L). The number ofthe utiliplantslant was different among the three ethnics. Tao Taa Wana people have utilized about 43 plant species, 27 of which were used for medicines, 20 for foods, 2 for natural dying, 18 for fuels, 6 for building materials, 5 for ritraditionaluonal ceremonies. In research site B (Singkoyo), 52 plant spe es have been extensively used by Javanese people for a wide range of culturally related activities, 28 species were used as medicine, 32 for food, 17 for fuel, 7 for building materials, and 10 for ornaments. Unlikely, in site C (Mentawa, 39 plant species were used traditionally by Balinese people; 18 of which were used for medicines, 18 for food, and 13 for ritual ceremonies).

Health assessment of vegetation composition in the reclamation area of PT Natarang Mining, Tanggamus Regency, Lampung Province

Reclamation is a recovery activity in mining areas, one of which is revegetation. The success of revegetation plants can be seen from the health of the composition and structure of the vegetation when the trees are six years old and over. This study aims to determine the health of the vegetation composition (location, type, and level of tree damage) in the reclamation area of PT Natarang Mining, Tanggamus Regency, Lampung Province. The location of this research is in the area around the main office of PT Natarang Mining, Way Linggo Forest, Bandar Negeri Semuong, Tanggamus Regency, covering an area of 2.97 Ha. The research was conducted through vegetation analysis using the circular plot method and assessing the health of the vegetation composition based on the damage index at the plot level. The results showed that tree vegetation obtained 12 species. The most common tree species found was Falcataria moluccana (Sengon) which amounted to 22 individuals. The most significant contribution of tree species indicated by the highest importance value index was Falcataria moluccana. The location of most damage found in most of the plots was at the bottom of the stem (code 3) and the bottom and top of the stem (code 4). Types of open wound damage (code 03) and gall rust (code 26) were the most dominant causes of damage, with an average damage rate of 35% and 22%, respectively. The health value of the vegetation composition has a value range of 1.20 – 2.00. The average health value of the vegetation composition is 1.50, which is included in the medium category.

Comparative assessment of dominant macrophytes and limnological parameters of Dal lake and Chatlam wetlands in the Union territory of Jammu & Kashmir, India

The aim of the study was to analyze and compare the physico-chemical properties of water, with respect to the anthropogenic stresses on the growth and dominance of aquatic macrophytes at the four selected sites in Dal lake and Chatlam wetlands, during the year 2020. We have identified 12 species of macrophytes from the Dal lake and 20 species from the Chatlam wetlands. Highest importance value index (IVI) was observed in Nymphoides peltata (48.98) during summer and the lowest IVI was in Mentha sp . (1.93) during winter in the Chatlam wetlands. On the contrary, in Dal lake the highest IVI values were reported for Azolla sp. (175.34) during summer and lowest for Hydrocharis dubia (10.60) during winters. The average values of Biological oxygen demand (BOD), Chemical oxygen demand (COD), nitrate nitrogen, ammoniacal nitrogen and orthophosphate content in Chatlam were 19.85 ± 0.91(mg/l), 62.5 ± 1.29 (mg/l), 516.25 ± 1.10 ( μ g/l), 291.75 ± 1.55 ( μ g/l) and 136.75 ± 0.47 ( μ g/l) respectively. While in Dal lake, the observed values of these parameters were 27.5 ± 1.49 (mg/l), 61.75 ± 0.85 (mg/l), 636.5 ± 1.04 ( μ g/l), 137 ± 1.31( μ g/l), and 44.6 ± 0.18 ( μ g/l), respectively. We found that the Chatlam wetland (sub-urban area) harbored more macrophytic diversity than the Dal lake (urban). Unplanned development and agricultural activities in the catchment area have significantly contributed to the cultural eutrophication. In lieu of these findings we propose that joint efforts of the researchers, government and the non-governmental organizations be put in for the sustainable conservation of these two wetlands. • Identification of dominant aquatic macrophytes in Dal and Chatlam lakes. • Analysis of the effect of anthropogenic activities on aquatic macrophytes. • Analysis of the physico-chemical properties of water in Dal and Chatlam lakes. • Conservation strategies on eco-restoration of the two lakes.

Composition, community structure, and vertical distribution of epiphytic ferns on Cyathea junghuhniana in Gede-Pangrango National Park, Indonesia

Abstract. Hasanah U, Hadisunarso, Praptosuwiryo TN. 2021. Composition, community structure, and vertical distribution of epiphytic ferns on Cyathea junghuhniana in Gede-Pangrango National Park, Indonesia. Biodiversitas 22: 4968-4976. Epiphytic ferns are a significant component of tropical forests worldwide and contribute significantly to the high species diversity found in tropical regions. Tree ferns are important phorophytes for the establishment and occurrence of epiphytic fern species in tropical forests. The first detailed description of the diversity and abundance of epiphytic ferns on the tree fern Cyathea junghuhniana (Kunze) Copel. in a natural forest of Indonesia is provided. This study aimed to determine the species composition, richness, abundance, community structure, and vertical distribution of epiphytic ferns growing on the tree fern C. junghuhniana in the mountain forest of Gede-Pangrango National Park, West Java, Indonesia. The 35 tree fern caudices of at least 3 m height were selected by purposive random sampling. Each tree fern was divided into intervals of 1 meter from ground level to a height of three meters, thus obtaining 105 one-meter samples of the epiphytic fern community on tree fern caudices stratified according to height. The Importance Value Index (IVI) was estimated for each species of epiphyte based on the frequency of occurrence on caudices. The 35 tree fern caudices hosted 760 fern epiphytes belonging to 12 species of 9 genera and 6 families. The highest species richness occurred in Polypodiaceae. The species with the highest Importance Value Index (IVI = 1.24 %) was Nephrolepis davallioides (Sw.) Kunze, with increasing frequency from bottom to top of the caudex.

Secondary succession of woody plants following sand mining in the Soesdyke-Linden area, Guyana: A Chronosequence study

Sandy soils comprise a large proportion of low productivity areas of Guyana on the Soesdyke-Linden Highway, where there is ecological disturbance and evidence of secondary succession after sand mining activities. This study investigated secondary succession of woody plants on abandoned sand mining locations. Secondary succession was studied inferentially by comparing sites in a homogeneous zone that was abandoned at different times post disturbance due to sand mining. Species diversity and community composition at five (5) sites which included an undisturbed area and areas at 3, 5, 10, and 15 years after the disturbance of sand mining were studied. Fifteen 10m x 10m plots were sampled for woody plants with a DBH of more than 2.5cm, and 1m x 1m sub-plots were randomly selected and sampled for seedlings with a DBH less than 2.5cm. A total of 241 plants were recorded, encompassing 22 species across 16 Families. Tapiria marchandii of the family Anacardiaceae dominated the chronosequences of 5, 10, and 15 years and recorded the highest Importance Value Index (IVI) of 112.88, 154.51, and 215.42, respectively. Dimorphandra conjugata of the family Fabaceae also adapted well to conditions post sand mining in the latter chronosequences of 10 and 15 years with IVIs of 54.17 and 38.83, respectively. The youngest site of three years exhibited the highest species diversity post the disturbance of sand mining; however, the undisturbed site possessed the highest overall species diversity. Species diversity of chronosequences decreased with age as competition for limited resources increased and the dominant species proliferated.

Composition and Pattern of Vegetation Distribution at the Tree Level in the Forest Area of Sorong Nature Tourism Park

This study aims to determine the species composition, frequency, density, dominance, important value index (INP) and the distribution of tree species. The method used in this research is the Line Transect Plot Method. The total area of the sample plots is 1 ha (10.000 m2) with a total of 25 sample plots, which are placed purposively at the study site. Observational data were analyzed according to the parameters and described qualitatively and quantitatively and presented in the form of tabulations and pictures. The composition of vegetation types in the Sorong Nature Tourism Park forest contains 50 plant species, namely 30 known families and 3 plant species not yet traded, scientific and family names. The number of tree levels is 36 species with the largest density value (K) for resak (Vatica papuana) and guava (Syzygium, sp ) which is 29.81/ha with a Relative Density (KR) of 15.897% with the smallest density value (K). 0.962/ha, and the value of relative density (KR) was 0.5128%, respectively. The largest frequency (F) value is found in guava with a value of 0.731, relative frequency (FR) of 13.19%, and the lowest value of frequency (F) is 0.038 %, the smallest relative frequency (FR) is 0.694%. With the largest dominance value (C) in resak plants of 2,561 and relative dominance of 15.95%, while the lowest dominance was 0.033 and relative dominance was 0.208%. Where the highest Importance Value Index (INP) is on the guava tree at 43.117 and the lowest Important Value Index (INP) is in the Trichadenia tree, sp 1.3964. The distribution pattern at the tree level is based on the morista index, which is spread in groups or in clusters.Keywords: Composition, Vegetation, Nature Park

STRUKTUR KOMUNITAS MANGROVE DI PESISIR DESA TATENGESAN, KECAMATAN POSOMAEN, KABUPATEN MINAHASA TENGGARA

The purpose of this study was to examine the structure of the mangrove community on the coast of Tatengesan, Posomaen District, Southeast Minahasa Regency, North Sulawesi. The data collection of the mangrove community structure used the line transect quadratic method measuring 10 m x 10 m 5 times. The research implementation period is 6 (six) months in 2021, starting from the preparation of proposals, data analysis, examination of research results, and the implementation of thesis examinations. Based on the results of the study, found 3 types of mangroves, namely: Rhizophora apiculata, Rhizophora mucronata, and Bruguiera gymnorrhiza. The value of the highest species relative density was found on transect 2 with a value of 88.33% by R. mucronata. For the value of the highest relative frequency of species on transects 1,2 and 3 by R. mucronata, namely 8.3 cm/m. The highest relative species cover was R. mucronata with a value of 76.99% on transect 2. The highest important value index was found in R. mucronata, which was 220.88 on transect 2. The highest diversity index was found on transect 3 with a value of 0.85. The highest evenness index was found on transect 1 with a value of 0.99. For further research, it is necessary to conduct an inventory of mangrove species using the roaming method to find out all the species in the research location.Keywords: Mangrove, Tatengesan, Community, Diversity and Evenness

STRUKTUR KOMUNITAS MANGROVE DI KELURAHAN TAPUANG, KECAMATAN TAHUNA, KABUPATEN SANGIHE

The information about mangrove forest community structure in Tapuang village has never been reported. The location of the mangrove forest in this village is near to the settlements. Three line transects with 50 m distance were laid perpendicular to the shore. In each line transect, 5 quadrants (10 x 10 m2) were established. The data were analyzed using several parameters density, frequency, dominance, important index value and diversity. This study found 5 mangrove species namely Avicennia marina, Sonneratia alba, Sonneratia ovata, Rhizophora stylosa and Nypa fruticans. Avicennia marina was the most species found in each transects and had the highest density, frequency, and dominance values. The highest important value index (INP) was found in Avicennia marina in transect 2 with a INP value 183.80. Mangrove species diversity index for tree category in each transect was low (H'≤1) ranges from 0.99.Key Words: Tapuang Village, Mangrove, Community Structure

Vegetation Analysis of Invasive Plants in Batang Gadis National Park Resort 7 Sopotinjak


 Introduction: The purpose of this study was to determine the type and diversity of invasive plants in Batang Gadis National Park (BGNP).
 Materials and Methods: This study was conducted in Batang Gadis National Park Resort 7 Sopotinjak, Mandailing Natal from February until April 2021. This study using the quadratic method by making transects and each transect is divided into 8 plots. Laying plots by purposive sampling as many as 8 plots.
 Results: BGNP Resort 7 had the invasive plants consisted of 12 families, 20 species and 1287 individuals. The highest species was found in Melastoma malabathricum L (230) and the highest important value index was found in Strobilanthes reptans (35.82%), while the species with the lowest significance index was Ageratum conyzoides (3.40%). The invasive plant diversity index was categorized as moderate (H'= 2.43).

ANALISIS STRUKTUR DAN KOMPOSISI TUMBUHAN ASING INVASIF (INVASIVE SPECIES) PADA KAWASAN GUNUNG SIBUATAN DESA NAGALINGGA KECAMATAN MEREK KABUPATEN KARO SUMATERA UTARA

<p align="center"><strong>ABSTRACT</strong></p><p>Foreign Plants Invasive<em> </em>(Invasive Species) have the ability to grow and develop very quickly in an ecosystem so that they can cause environmental damage. The purpose of this research is to find out the structure and composition of weed plants in the area of Mount Sibuatan, Nagalingga Village, Brand District, Karo Regency, North Sumatra, using the checkered line method with 10 x 10 m in size plot which is placed by purposive sampling. Based on the research that has been carried out, it was obtained 20 families of 34 species with 452 individuals that divided into three levels of vegetation, namely trees, sapling and basic vegetation. The dominant families found consisted of the Asterceae and Euphorbiaceae families with 64.12% and 76.43% of percentage, the co-dominant families were the Poaceae and Rosaceae families with 17.06 and 16.20% of percentage. The highest Importance Value Index (INP) of the area is the species of <em>Austroeupatorium inulifolium</em> (Kunth) R.M.King & H. Rob with a value of 92.37. The invasive plants diversity index has moderate abundance of plant diversity. The spread patterns of invasive plants are include into the category of groups.</p>

Vegetation diversity and stand carbon stocks in Wana Wisata Tampora, Situbondo, East Java

Forest degradation and industrial development have a negative impact on the global climate. Forest vegetation plays a role in absorbing CO2 emissions in the air. The aims of this research are to determine vegetation community structure, plant diversity indices, and estimation of stands carbon stocks in Wana Wisata Tampora, Situbondo district, East Java. The research was conducted using the transect method and measured the diversity indices including Shannon-Wiener diversity index (H'), richness index (R), and evenness index (E), while the carbon stock was estimated using an allometric equation. The results showed that the diversity index value at the ground cover layer was considered high (3.18), while saplings and trees were moderate (2.68 and 2.60). The results of the stands carbon stocks estimation have shown an average value of 145.94 tonnes/ha. Plant species with high Important Value Index (IVI) and carbon contributor including Schleichera oleosa (83.97 and 56.49 ton/ha), Lannea coromandelica (58.88 and 32.35 ton/ha), Tectona grandis (24.72 and 8.5 ton/ha), Azadirachta indica (20.72 and 8.27 ton/ha), and Acacia nilotica (9.40 and 8.39). The results of the research will be useful for local governments as the basis for the development of Wana Wisata Tampora and the management of flora biodiversity.

Assessing the effects of Salicornia brachiata Roxb. growth on coastal saline soil quality over temporal and spatial scales

Global climate change and human interference gradually increase the salt-affected land; hence the availability of agricultural land is decreasing day by day. Higher salinity severely affects the physical, chemical and biological characteristics of the soil. Various studies investigated the effects of growing crop plants on soil quality but such investigations on halophytic plants in their natural habitat are limited. Salicornia brachiata was selected to assess its effects on the soil quality over temporal and spatial scales because of its highest importance value index among the naturally growing coastal halophytes at the studied sites. The root zone soil of S. brachiata was sampled (six times in one growing period) from six different coastal sites in Gujarat, India. Soil characteristics, microbial community composition (ester linked-fatty acid methyl ester profiling) and genes (16S rRNA, nifH and cbbL) abundance in comparison with control soil (without vegetation) were studied. The root zone soil of S. brachiata had significantly higher pH, K+ and P, and lower EC, NO3–-N, NH4+-N and Na+ contents than control soil. The contents of total, GM+ve, GM−ve, total bacterial, fungal and actinomycetes FAMEs (fatty acid methyl esters) were higher in the S. brachiata covered soils (37.98, 6.44, 10.38, 16.35, 1.74 and 2.12 nmol g−1, respectively) than control soils (22.22, 3.81, 5.47, 9.30, 0.77 and 1.23 nmol g−1, respectively). Among the studied sites, root zone soil from Diu possessed the highest total, bacterial (GM+ve and GM−ve), fungal and actinomycetes FAMEs, whereas the Vivaniya site exhibited the lowest. Among the sampling periods, S. brachiata soil exhibited significantly elevated contents of total FAME and FAME biomarkers of microbial taxonomic groups in the initial two sampling months (August and October), followed by December and the least in June. Compared with control soil, S. brachiata covered soil possessed the microbial community shift related to the enhanced abundance of total bacterial, GM−ve and fungal FAMEs. The abundance of 16S rRNA, cbbL and nifH genes was higher in S. brachiata covered soils (1.64 × 109, 5.06 × 106 and 2.53 × 107, respectively) compared with control soil (6.78 × 108, 1.55 × 106 and 6.99 × 106, respectively). In the August and October months, the abundance of all three genes was highest in S. brachiata and control soils. The findings of this study confirm the significant effects of S. brachiata on saline soil properties (soil characteristics, microbial activities and genes abundance) over temporal and spatial scales. The results strongly suggest the potentials of S. brachiata for the restoration of salt-affected degraded lands for healthy ecosystem functioning.

THE STUDY OF TREE LEVEL IN ANGGOMATE WATERSHED AREA , SOUTHEAST SULAWESI

Anggomate River has ecological and economic value for the local community. Massive community activities in utilizing land in the Anggomate watershed area for plantation, inhabitation, and sand mining lands can cause the tree vegetation decline, even flood often occurs in Andowia region annually. The research method used was a quantitative method. Sampling was performed through a plot-transect method. The plots were placed on the downstream (Labungga Village river area), middle (Laronaga Village river area), and upstream (Andowia Village river area) regions. The study results showed that there are 35 tree species with the individual number of 64. The highest importance value index was obtained from Ficus benjamina L. at 29.38%, Anthocephalus cadamba (Roxb.) Miq) at 25.64%, and Lansium domesticum Corr. at 16.81%. The dominance index of the tree species in the Anggomate river area was 0.971, which indicates that one of the tree species dominated this area, namely, Anthocephalus cadamba (Roxb.) Miq) (Roxb.) Miq). The diversity index in the Anggomate watershed area includes in high category (H’= 3.402 atau H’ > 3). The distribution index includes in the evenly distribution category due to obtaining closely approaching the value of 1 (E= 0.818).

KEANEKARAGAMAN DAN KEGUNAAN TUMBUHAN BAWAH PADA BEBERAPA TEGAKAN DI ARBORETUM BALAI PENELITIAN DAN PENGEMBANGAN TEKNOLOGI SERAT TANAMAN HUTAN (BP2TSTH) KUOK

Underground plants have an important role in soil and air conservation efforts, namely as a source of organic matter, preventing erosion, a source of germplasm and increasing air infiltration into the soil. This study aims to identify the types, diversity and use of understorey under stands of meranti, gaharu and mixed stands in the arboretum of the Kuok Forest Plant Fiber Technology Research and Development Institute (BP2TSTH). The data collection method used systematic sampling with a random start, with a sampling intensity of 5%. The number of plots observed for meranti, gaharu and mixed stands were 50, 25 and 25, respectively, with a plot size of 2 x 2 (m). In the stands were found 17 families of undergrowth consisting of 23 species and 10,338 individuals. In the agarwood stands there are 10 families of undergrowth consisting of 13 species and 9,696 individuals. In the agarwood stands there are 11 families with a diversity of 13 species and 10,328 individuals. Diversity Index and Evenness Index in meranti, gaharu and mixed stands respectively; 1.25 and 0.4; 0.72 and 0.28; 0.72 and 0.28. Paspalum conjugatum is a understorey species with the highest Importance Value Index (IVI) in the three stands.

ANALISIS VEGETASI TUMBUHAN LIANA DI GUNUNG SIBUATAN DESA NAGALINGGA KECAMATAN MEREK KABUPATEN KARO SUMATERA UTARA

Lianas are a unique group of climbing plant species that are characteristic of tropical rainforests. This species has important ecological and economic value. This study aims to find out information about the composition and structure and diversity index of lianas. The research method used is a quadratic method with 10 plots laid out by purposive sampling. The results showed that the composition of lianas consisted of 22 families, 31 species and 414 individuals. The highest Importance Value Index in <em>Amydrium humile</em> Schott (INP 23, 145%), where as liana species with the lowest of Value index was<em> Stephania</em> sp. (INP 2, 343%). The diversity index of lianas is in the medium category, with the H’ 2.965.

Plant diversity, structure and composition of vegetation around Barumun Watershed, North Sumatra, Indonesia

Abstract. Rambey R, Susilowati A, Rangkuti AB, Onrizal O, Desrita, Ardhi R, Hartanto A. 2021. Plant diversity, structure and composition of vegetation around Barumun Watershed, North Sumatra, Indonesia. Biodiversitas 22: 3250-3256. Watershed ecosystem plays an important role in water and soil conservation which is supported by vegetation around watershed. As such, vegetation analysis is beneficial to assess the current state of watershed vegetation and monitor future changes. Barumun Watershed, located in South Labuhanbatu District, North Sumatra Province, Indonesia, is under threat due to habitat degradation and land conversion for plantation and agriculture. This research aimed to investigate the diversity, structure and composition of vegetation in the Barumun River including its smaller streams (rivulets). Data were collected using a combination of line transect and quadratic plots arranged systematically. The total observation plots were 48 plots, consisting of 24 plots in Barumun River, 12 plots in Tasik Rivulet and 12 plots in Titi Kembar Rivulet. The results documented a total of 51 plants in the studied sites in Barumun Watershed in which 37 species were found in Barumun River, 20 species in Tasik Rivulet and 17 species in the Titi Kembar Rivulet. Plant species consisted of several habitus including herbs, palms, shrubs, climbers and trees. The trees consisted of 22 species (43.13%), herbs 22 species (43.13%), climbers 3 species (5.88%), shrubs two species (3.92%), and palm two species (3.92%). The highest Importance Value Index (IVI) for tree community was recorded in the Barumun River from Hevea brasiliensis (108.28), followed by Cryptocarya sp. (123.24) in the Titi Kembar Rivulet. In addition, the highest IVI for pole, sapling, seedling, and shrub was recorded from Muntingia calabura (Barumun River), Nauclea orientalis (Tasik Rivulet), Psychotria viridiflora (Tasik Rivulet), and Calamus axillaris (Titi Kembar Rivulet), respectively. The plant diversity in Barumun Watershed was categorized from low to moderate level of richness.

Vegetation structure, aboveground biomass, and carbon storage of wono¸ a local forest management in Gunungkidul, Yogyakarta, Indonesia, across three geomorphological zones

Abstract. Tohirin, Suryanto P, Sadono R. 2021. Vegetation structure, aboveground biomass, and carbon storage of wono¸ local forest management in Gunungkidul, Yogyakarta, Indonesia, across three geomorphological zones. Biodiversitas 22: 3207-3218. Wono is local community-based forest management in Gunungkidul District, Yogyakarta. This land use has the potential to reduce carbon dioxide emissions through their carbon sequestration capacity as well as to produce renewable energy sources through wood biomass for charcoal and wood pellet. Since Gunungkidul is unique in terms of geomorphological characteristics, study on the vegetation structure, biomass estimation, and carbon storage of wono across geomorphological zones are important. Therefore, this study describes the vegetation structure of wono in three geomorphological zones of Gunungkidul District, as well as estimates the aboveground living biomass (AGB) and aboveground living carbon storage (AGC). The quadratic sampling technique was used to collect data for vegetation analysis with the size of the plots were 20 m x 20 m, 10 m x 10 m, 5 m x 5 m, and 2 m x 2 m for trees, poles, saplings, and seedlings, respectively. A total of 32 plots were established, consisting of 18 plots in Nglanggeran Village, 12 plots in Dengok Village, and six plots in Girisekar Village, each village representing geomorphological zones of Batur Agung, Ledok Wonosari, and Pegunungan Seribu, respectively. The AGB was performed non-destructively and estimated using referenced allometric equations. Furthermore, the AGC was calculated using a conversion factor of 0.47 from the obtained AGB. The results showed that the identified species at wono in Batur Agung, Ledok Wonosari, and Pegunungan Seribu zones were 13, 7, and 8, respectively. Swietenia macrophylla had the highest important value index (IVI) of 185.22% in the Batur Agung zone, while Tectona grandis was the most important species in both the Ledok Wonosari and Pegunungan Seribu zones with IVI= 238.27% and 178.60%, respectively. The biodiversity in these three zones was very low in terms of species diversity (H' < 2) and species richness (R1 < 3.4). The estimated AGB and calculated AGC in the Batur Agung, Ledok Wonosari, and Pegunungan Seribu zones were 210.96 ton ha-1 and 99.15 ton C ha-1, 73.58 ton ha-1 and 34.58 ton C ha-1, and 57.92 ton ha-1 and 27.22 ton C ha-1, respectively.

Technology Levels in Cassava Cultivation Alter Phytosociology of Weeds

This study aimed to assess the phytosociology of weeds as a function of different crop management technology levels in cassava production. Field experiments were conducted in Santa Maria (29°41′03″ S; 53°48′25″ W) and Itaqui (lat. 29°07′31″ S; long. 56°33′11″ W), Rio Grande do Sul, Brazil. Treatments consisted of three technology levels: low (postemergence weeding without basal dressing); medium (weeding performed at 7 and 40 days after planting and fertilization with 6.25, 25, and 25 kg⋅ha−1 of N, P, and K, respectively); and high (postemergence application of s-metolachlor; 1250 kg⋅ha−1 of lime and 12.5, 50, and 50 kg⋅ha−1 of N, P, and K, respectively). Weed frequency, density, relative abundance, and importance values were calculated for each location. Then, locations were compared using a dissimilarity matrix. Weed density and diversity decreased linearly as technology levels increased. The predominant weed species found in Itaqui and Santa Maria belong to the Poaceae family. Itaqui presented highest weed diversity among the locations. The genus Cyperus had the highest importance value index in Santa Maria. The use of S-metolachlor at the high technology level provided a lower frequency and lower diversity of weed species than did levels without chemical control in Itaqui and Santa Maria.

STRUKTUR KOMUNITAS HUTAN MANGROVE DI DESA BUDO KECAMATAN WORI KABUPATEN MINAHASA UTARA

Mangrove forest can grow on the muddy soil, along the coast and around the river estuaries that are affected by the tidal. The mangrove forest has a specific vegetation structure. Study on the structure of the mangrove forest community, was carried out in the Budo Village. Mangrove community structure data was taken using line transect method. A 100 m line was established from the sea perpendicular to the coast. A total of three line transects was made and each line has five 10 x 10 m plots with 20 m distance between plots. Distance between transect is 50m. This study found that three mangrove species Rhizophora apiculata, Sonneratia alba, and Bruguiera gymmorrhiza were found in the three transects during this study. The highest species biodiversity index was found in transect two (H’ = 0.97). R. apiculata has the highest density and relative density 0.05 ind/m2 and 67.57%. Both R. apiculata and S. alba have the highest frequency and relative frequency of 1.00 and 50% respectively. The highest species coverage and relative coverage area is belonging to S. alba in transect two, 25,89 and 63.57%. S. alba has the highest Important value index 140.72 in transect two.Keywords: Budo Village, Mangrove Forest, Community Structure.