SPATIAL DISTRIBUTION OF INVASIVE PLANTS IN BANDUNG, WEST JAVA, INDONESIA

The urban area is a source of invasive plants that enter through human activities such as agriculture and land-use conversion. Studying the invasive plant in urban areas is essential to understanding the city’s ecosystem health condition. Therefore, this study aims to inventory invasive plants, map their distribution, and explain the relationship between land use with the community diversity and species richness of invasive plants in Bandung. The vegetation analysis was performed using line-transect in 22 study sites distributed using a systematic random sampling method in Bandung to observe the plant species composition. The study plots were placed based on the land-use type. The species name, individual number, frequency, and sampling site locations were noted and analyzed to calculate the important value index (IVI) and the invasive species distribution pattern using the principal component analysis (PCA). The dominant invasive species was spatially mapped. Six types of land use were used in this study, i.e., settlements, street green lanes, gardens, paddy fields, urban parks, and urban forests. There were 187 species found in Bandung, which can be categorized into alien invasive species (39%), invasive native plants (25%), non-invasive alien species (18%), non-invasive native species (15%), and unidentified plants (3%). The most common invasive plants found were Eleusine indica (IVI=10.50%), Trimezia martinicensis (IVI=7.22%), and Cyperus rotundus (IVI=6.74%). Based on the plant community similarity index, the study area with the highest similarities were paddy fields with gardens (50.5%), settlements with road lanes (44.4%), urban parks with road lanes (26.2%), and urban forests with road lane (17.5%). PCA showed Swietenia macrophylla as the most common invasive plant found in urban forests, urban parks, and road lanes, with air humidity as the most influencing environmental factor. Trimezia martinicensis is the most common species in the settlement area affected by high air humidity. Bidens pilosa is an invasive plant commonly found on paddy fields, gardens, settlements, road lanes, and urban park edges. This species can easily and rapidly reproduce with a high survival rate. The many invasive plants found in Bandung must be managed to maintain the urban ecosystem’s health

Fungsi Taman Kota Untuk Mitigasi Dampak Urban Heat Island di Kota Bandung: Ecological Function of Forest Park to Mitigate Urban Heat Island in Bandung

Forest parks can take a role in mitigating negative impact of Urban Heat Island. Therefore, this study was conducted to clarify ecological function of three forest parks i.e Ganesha, Maluku, and Tegalega forest park in mitigating Urban Heat Island. Land classification and surface temperature were determined by analyzing Landsat 8 image with QGIS. Air temperature was measured by mobile station through north-south and east-west of Bandung City area. There are four types of land classification in Bandung as follows: settlements, water body, bare soil, and vegetation. In Bandung City, vegetation cover is around 20.72%; surface temperatures in the afternoon varies from 23 to 39.6°C, while during the night air temperatures varies from 20.5 to 24.9°C. Northern part of Bandung tends to have cooler air temperature due to high coverage of vegetation. Tegalega forest park can reduce temperature up to 2.6°C, while in Maluku forest park is 1.98°C and Ganesha forest park is 0.75°C. Therefore, the existence of forest parks is important in urban area because they can take a part to reduce negative impact of Urban Heat Island. &nbsp

Tree Community Structure and Composition of a One-Hectare Permanent Plot in the Montane Zone of Mount Kerinci, Kerinci Seblat National Park, Jambi

Information on tree community structure and composition is needed in forest management and restoration. These data can be obtained using a permanent plot for studying forest dynamics, including species-specific characteristics. These characteristics are useful in the identification of native species for commercial and restoration purposes. This study aimed to describe the tree community structure and composition of a one-hectare permanent plot in the montane zone of Mount Kerinci. Data collection was conducted from July to August 2016 on Mount Kerinci, Jambi. A plot was established at 2,182-2,258 m above sea level and subdivided into 100 subplots. All trees ≥ 10 cm DBH were tagged and measured. Twenty-eight species, 18 genera, 20 families, 570 individuals and Shannon index 2.89 were identified. Most of the potential species richness was covered on the research site. Syzygium lineatum was the species with the highest importance value and Myrtaceae had the highest family importance level. The study area was dominated by slow growing species that characterize primary forests. The population structure indicated a good capacity of forest regeneration, while the vertical structure formed a stratification consisting of three strata. The dominant large trees and 5 hyperdominant trees according to total biomass contribution were identified. These species are an important priority in forest management and restoration.

AKTIVITAS HARIAN ORANGUTAN KALIMANTAN (Pongo pygmaeus) PASCA PELEPASLIARAN DI HUTAN LINDUNG GUNUNG TARAK, KALIMANTAN BARAT

Orangutan kalimantan (Pongo pygmaeus) pasca rehabilitasi membutuhkan waktu untuk bisa bertahan hidup di habitat aslinya setelah dilepasliarkan. Penelitian ini bertujuan untuk melihat aktivitas harian orangutan pasca rehabilitasi. Penelitian ini dilakukan di hutan Gunung Tarak, Kalimantan Barat. Pengamatan perilaku orangutan dilakukan dengan metode focal animal sampling dan instantaneous sampling per dua menit. Pengamatan dilakukan terhadap dua individu orangutan Susi dan Peni yang sudah dilepasliarkan setelah melewati masa rehabilitasi. Ada lima aktivitas harian dari dua orangutan pasca rehabilitasi yang diamati yaitu perilaku makan Susi 54% dan Peni 52%, istirahat Susi dan Peni sama yaitu 17%, traveling Susi dan Peni sama yaitu 9%, interaksi dengan manusia yaitu Susi 1,3% dan Peni 0,6%, aktivitas membangun sarang Susi dan Peni sama yaitu 1%. Berdasarkan data aktivitas harian Susi dan Peni maka dapat disimpulkan bahwa aktivitas harian Susi dan Peni tidak jauh berbeda meskipun berbeda masa pelepasliaran dan orangutan pasca pelepasliaran membutuhkan kurang lebih dua atau tiga tahun untuk bisa hidup mandiri dan bertahan hidup di habitat alaminya

Plukenetia volubilis L.: A New Record of a Cultivated Alien Species in Java

Plukenetia volubilis L. has been documented as a new record for the first time in Java, Indonesia. The species is easily distinguished from the native species, P. corniculata Sm., by its exstipellate basilaminar-glands, long cylindrical column, and wingless fruit-lobes. Plukenetia volubilis is cultivated mainly in South America for its beneficial values as food and medicine and was recently introduced to Asia. However, its occurrence in Java has not been reported. We collected specimens from West Java (Depok City, Bandung Barat and Sumedang Regency) and East Java (Malang Regency). Morphological description, identification key, and photographs of the species are provided

Analyzing the Changes in Land Cover and Land Surface Temperature (LST) in the North Bandung Area (NBA)

North Bandung Area (NBA) was designated as a protected area to regulate the water system around Bandung City. Land conversion from vegetated land into built-up areas can decrease groundwater, increase the risk of floods, landslides, and Land Surface Temperature (LST). This study was conducted to describe LST distribution based on land cover types in specific years of 2010, 2014, and 2018. Landsat 5 and 8 Surface Reflectance (SR) Tier 1 imagery data, West Java land cover maps established by BAPPEDA West Java, and RBI administration maps at a scale of 1: 25,000 were used to generate a map of land cover and LST in this research. There are four land cover classes in NBA, i.e., vegetation, water bodies, open areas, and constructed areas. Within eight years observation (2010 to 2018), bare land decreased from 67.6% (2010) to 57.5% (2018). However, coverage of constructed areas increased within eight years of observation from 22.8% to 27.7 %. In addition, due to the reforestation program, vegetation coverage has slightly increased from 9.6% to 14.7%. LST can be classified into three classes, i.e., low, medium, and high temperature. The area with low and medium-class temperatures decreased from 19% to 16% and 61.3% to 51.7%, respectively. However, high LST increased in NBA 18.7% to 30.3%. The enhancement of 5% vegetation area did not significantly reduce land surface temperature in NBA due to forest conversion to constructed area. Therefore, vegetation coverage must be escalated by reforestation program around NBA to reduce land surface temperature

THE EFFECT OF LAND USE HISTORY ON NATURAL FOREST REHABILITATION AT CORRIDOR AREA OF GUNUNG HALIMUN SALAK NATIONAL PARK, WEST JAVA INDONESIA

Corridor area of Gunung Halimun Salak National Park was degraded and fragmented by human activities. However, little is known about recovery process in tropical degraded forest under different land use history. To clarifyvegetation structure and forest recovery related to land use history we placed 22 plots (11 of 10 x 10 m2 in abandoned plantation and 11 of 20 x 20 m2 in secondary forest, respectively). DCA (Detrended correspondence analysis) discriminated the plots into three community groups. Swieteniamacrophylla –Agathisdammaa community in abandoned plantation where had a land use history of clear felling.Maesopsiseminii–Cyathea spp. community had a history of severe human disturbance. Fagaceae-Schimawallichii was in less disturbed forest. Below the plantation canopy, light tolerant species, weeds, grasses, and fern of Dicranopteris linearis were dominant. Some exotic plants spread to the disturbed forest. The less disturbed forest in distant area from village remained in good condition as indicated by dominancy of old forest species. For the forest rehabilitation in severely degraded area, human intervention by planting native species can be suggested to avoid invasive species occupancy as well as accelerate forest recovery

Melothria pendula L. (Cucurbitaceae): first report from Java and range extension in Sumatra, Indonesia

Melothria L. (Cucurbitaceae) is a Neotropical genus of wild cucumber comprising 12 species. The only species that occurs in Malesia is M. pendula L., which has been recorded in Peninsular Malaysia, Borneo, mainland Sumatra, the Philippines, Sulawesi, and Bali. During our botanical excursions in Bangka and West Java from 2020 to 2022, we discovered naturalized populations of M. pendula. Our findings reveal that M. pendula has an extensive distribution in Sumatra and is a newly recorded wild cucumber in Java. We present a morphological description, photographs, and a brief discussion

Infectious Disease Modeling with Socio-Viral Behavioral Aspects—Lessons Learned from the Spread of SARS-CoV-2 in a University

When it comes to understanding the spread of COVID-19, recent studies have shown that pathogens can be transmitted in two ways: direct contact and airborne pathogens. While the former is strongly related to the distancing behavior of people in society, the latter are associated with the length of the period in which the airborne pathogens remain active. Considering those facts, we constructed a compartmental model with a time-dependent transmission rate that incorporates the two sources of infection. This paper provides an analytical and numerical study of the model that validates trivial insights related to disease spread in a responsive society. As a case study, we applied the model to the COVID-19 spread data from a university environment, namely, the Institut Teknologi Bandung, Indonesia, during its early reopening stage, with a constant number of students. The results show a significant fit between the rendered model and the recorded cases of infections. The extrapolated trajectories indicate the resurgence of cases as students’ interaction distance approaches its natural level. The assessment of several strategies is undertaken in this study in order to assist with the school reopening process