• Journal of Ecology and Environment
• /
• v.44 no.2
• /
• pp.90-97
• /
• 2020

Background: Natural forests are generally considered to be less prone to biological invasions than other modified ecosystems, particularly when canopy cover is high. Few decades of management of degraded forests by local communities in Nepal has increased canopy cover and altered disturbance regimes. These changes might have reduced the abundance of invasive alien plant species (IAPS) in forests. To understand the status of IAPS in such forests, we studied two community managed Shorea robusta forests (Sundari and Dhusheri) of Nawalpur district in central Nepal. In these two forests, vegetation sampling was done using circular plots 10 m radius at forest edge, gaps, and within canopy. Variation of IAPS richness and cover across these microhabitats were compared, and their variation with tree canopy cover and basal area analyzed. Result: Altogether 14 IAPS were recorded in the study forests; among them Chromolaena odorata, Ageratum houstonianum, and Lantana camara had the highest frequency. Mikania micrantha was at the early stage of colonization in Sundari Community Forest (CF) but absent in Dhuseri CF. Both IAPS cover and richness was higher at forest edge and gap than in canopy plots and both these attributes declined with increasing canopy cover and tree basal area. Conclusion: The results indicate that increase in canopy cover and closure of forest gaps through participatory management of degraded forests can prevent plant invasions and suppress the growth of previously established IAPS in Shorea robusta forests of Nepal. This is the unacknowledged benefit of participatory forest management in Nepal.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.25 no.4
• /
• pp.123-140
• /
• 1998

The flora of Kunsan Wolmyong park was 77 families, 168 genera, 240 species, 2 subspecies, 35 varieties, 1 formae or 278taxa. Using the Phytosociology method, 12 plant communities were recognized ; Alnus japonica, Pinus densiflora, Pinus thunbergii, Pinus rigida, Castanea crenata, Quercus acutissima, Robinia pseudo-acacia, Alnus hirsuta, Quercus serrata, Aluns firma, Liriope platyphylla and Reynoutria communities. Similarity between different communities was low for most of the cases except for Pinus densiflora, Pinus Thunbergii and Pinus rigida communities kept comparely high with ond another. Species diversity was analyzed by species richness(SR), species diversity index(H') and evenness(J'). Castanea crenata, Robinia pseudo-acacia and Alnus firma communities were higher in SR, H' than the other communities. But Pinus rigida, Quercus acutissima and castanea crenata communities were higher in evenness than the other communities. To investigate the plant community structure and to establish restoration counter plan of a Wolmyeng Park in Kunsan City. As a remedial approach, following is propesed. first, Establishment of an adequate planting plan and development of slope stalilization method by planting native species. second, Sellection of adequate species by planting experiments for pioneer species, native species, and dietary species. third, Landscape planting zones should be managed artificially, the others be managed with ecological approach.

• Korean Journal of Ecology and Environment
• /
• v.51 no.4
• /
• pp.322-330
• /
• 2018

Herbivory is a major functional component of forest ecosystems, and herbivorous insects comprise about 25% of all insect species. Increasing plant diversity is related to herbivore abundance and diversity, which affects the level of leaf damage caused by insects. This study was conducted to identify plant-related variables such as plant diversity and number of leaves and density-related variables, basal area, and diameter at breast height (DBH) in a temperate forest of southern South Korea. To assess the level of leaf damage caused by leaf chewing insects, we set up two 0.1 ha plots in a temperate deciduous forest on Mt. Jirisan National Park. Plant richness differed between two sites: 16 species in 14 families(site 1) and 19 species in 15 families (site 2). Fisher's alpha index based on plant species richness and abundance resulted in 4.41 (site 1) and 6.57 (site 2). However, the sum of basal area of each site was higher in site 1 ($6.6m^2$) than site 2 ($3.7m^2$). The total surveyed leaves at two sites were 3,832 and 4,691, respectively and the damage leaves were 1,544 and 2,136, respectively. The mean leaf damage level was 11.2% (${\pm}1.76%$) in two study sites: the leaf damage level of the site 1 (11.99%) was significantly higher than site 2 (10.59%). Stepwise regression analysis showed that species diversity and evenness were the significant variables for leaf damages by chewing herbivores. NMDS ordination also identified that high tree density and low species diversity were the significant variables. This suggested that the level of damage was significantly higher in plots with low plant diversity and high tree density. In the future, we will investigate other guilds of herbivores such as sap-suckers, miners and gallers in temperate deciduous forests.

• Korean Journal of Organic Agriculture
• /
• v.6 no.2
• /
• pp.75-80
• /
• 1998

Organically cultured rice fields were surveyed to compare the population density and the structure of microarthropod communities between chemically controlled and un-controlled fields. In rice fields, microarthropod communities were also compared among four treatments based on different input of fertilzer : 1)No fertilizer, 2)Chemical fertilizer(N-P2O5-K2O = 11 - 7 - 8 kg/10a, 3) Compost (5,000kg/10a), 4) Compost com-plemented with chemical N. Richness index of microarthropod communities in rice fields was greater in the chemically uncontrolled field than controlled field. Within field. the compost plot had greater value of richness index for microarthopod commuities than the non-fertilizer polt. A total of 9 aquatic insects species were identified in the water of organic farming rice field the population density was found to be higher in the compost plot than the other plot. The population of insect pests was found to be high in the late stage of plant whereas the population of insects was high in the early stage of rice plant.

• Journal of Environmental Impact Assessment
• /
• v.20 no.5
• /
• pp.663-673
• /
• 2011

In the face of accelerating biodiversity loss and its significance in our coexistence with nature, biodiversity is becoming more crucial in sustainable development perspective. To estimate biodiversity in the future which provides valuable information for decision making system especially in the national level, a quantitative approach must be studied forehand as a baseline of the present status. In this study, we developed a large-scale map of Plant Species Richness (PSR, typical indicator of biodiversity) for Young-dong and Pyung-chang provinces. Due to the accessibility of appropriate data and advance of modelling techniques, reduction of variables without deteriorating the predictive power is considered by applying Genetic algorithm. In addition, a number of Correctly Classified Instances (CCI) with 10-fold cross validation which indicates the predictive power, was carried out for evaluation. This study, as a fundamental baseline, will be beneficial in future land work as well as ecosystem restoration business or other relevant decision making agenda.

• The Korean Journal of Ecology
• /
• v.21 no.3
• /
• pp.233-241
• /
• 1998

In order to test of intermediate disturbance hypothesis that an intermediate level of disturbance maximize biodiversity and to elucidate the effect of disturbance during the early old-field succession, the response of plant community along an experimental disturbance gradient was investigated in a five-year old-field. Response of plant community along an experimental disturbance gradient was connected with light condition because artificial disturbance gradient had been treat by clipping of plants and removing of litter. Artificial disturbance in five-year old-field plant community retarded rate of succession by increasing invasion and performance of the earlier successional species in the initial and middle stage of disturbance treatment. The species richness in the blocks of intermediate disturbance level showed the peak in early and mid-summer. This result did correspond with the prediction of intermediate disturbance hypothesis.

• Journal of Forest and Environmental Science
• /
• v.36 no.2
• /
• pp.91-112
• /
• 2020

In Ethiopia, dry land vegetation including the fairly intact lowland and western escarpment woodlands occupy the largest vegetation resource of the country. These forests play a central role in environmental regulation and socio-economic assets, yet they received less scientific attention than the moist forests. This study evaluated the woody plant species composition, population structure and carbon sequestration potential of the A. senegal woodland across three distance gradients from the settlements. A total of 45 sample quadrants were laid along a systematically established nine parallel transect lines to collect vegetation and soil data across distance gradients from settlement. Mature tree dry biomass with DBH>2.5 cm was estimated using allometric equations. A total of 41 woody plant species that belong to 20 families were recorded and A. senegal was the dominant species with 56.4 IVI value. Woody plant species diversity, density and richness were significantly higher in the distant plots compared to the nearest plots to settlement (p<0.05). The cumulative DBH class distribution of all individuals had showed an interrupted inverted J-shape population pattern. There were 19 species without seedlings, 15 species without saplings and 14 species without both seedlings and saplings. A significant above ground carbon (5.3 to 12.7 ton ha^-1), root carbon (1.6 to 3.6 ton ha^-1), soil organic carbon (35.6 to 44.5 ton ha^-1), total carbon stock (42.5 to 60.7 ton ha^-1) and total carbon dioxide equivalent (157.7 to 222.8 ton ha^-1) was observed consistently with an increasing of distance from settlement (p<0.05). Distance from settlement had significant and positive correlation with species diversity and carbon stock at 0.64^⁎⁎ and 0.78^⁎⁎. Disturbance intensity may directly influence the variation of species composition, richness and density along the A. senegal woodland. The sustainability of the A. senegal woodland needs urgent protection, conservation and restoration.

• Journal of Forest and Environmental Science
• /
• v.34 no.3
• /
• pp.209-223
• /
• 2018

We investigated tree composition, stand characteristics, biomass allocation pattern and carbon storage variability in Sal forests (Shorea robusta Garten.) under two forest management regimes (Sal forest and Sal plantation) in Tripura, Northeast India. The results revealed higher species richness (29 species), stand density of $1060.00{\pm}11.12stems\;ha^{-1}$ and diversity index ($1.90{\pm}0.08$) in Sal forest. and lower species richness (4 species), stand density of $ 230.00{\pm}37.22stems\;ha^{-1}$ and diversity index ($0.38{\pm}0.15$) in Sal plantation. The total basal cover $33.02{\pm}4.87m^2ha^{-1}$) and dominance ($0.76{\pm}0.08$) were found higher in Sal plantation than the Sal forest ($22.53{\pm}0.38m^2ha^{-1}$ and $0.23{\pm}0.02$ respectively). The total vegetation carbon density was recorded higher in Sal plantation ($219.68{\pm}19.65Mg\;ha^{-1}$) than the Sal forest ($167.64{\pm}16.73Mg\;ha^{-1}$). The carbon density estimates acquired in this study suggest that Sal plantation in Tripura has the potentiality to store a large amount of atmospheric carbon inspite of a very low species diversity. However, Sal forests has also an impending sink of carbon due to presence of large number of young trees.

• Journal of Forest and Environmental Science
• /
• v.28 no.4
• /
• pp.282-288
• /
• 2012

Spider fauna of Mt. Yongmunsan located in Yangpyeong-gun, Gyeonggi-do, was surveyed from April to October in 1996. A total of 75 species of 51 genera in 22 families from 996 individuals of spiders were identified. Species richness of each family, there were 17 Araneid species (22.7%), followed by each of the 7 Thomisid and Tetragnathid species (9.3%), 6 Salticid species (8.0%), and 5 Lycosid species (6.7%). Zoogeographically, spider fauna of Mt. Yongmunsan represented 1 cosmopolitan species (1.3%), 2 holarctic region species (2.6%), and 9 palearctic region species (12.0%), and 4 Korean endemic species (4.0%). Thus it is suggested that spider fauna of Mt. Yongmunsan was under northern regional influence.

• Journal of Environmental Science International
• /
• v.32 no.5
• /
• pp.329-341
• /
• 2023

We surveyed the vegetation of an ecological landscape preservation area (legally protected conservation areas or national parks) and the surrounding areas of Mt. Cheonggye, Republic of Korea, to explore the conservation implications for preservation areas and surrounding transition areas. We calculated diversity indices to identify the properties of the preservation and surrounding areas that are relevant to conservation efforts. We then compared the plant community composition between the areas using field and quadrat surveys in the preservation and surrounding areas. The cover of the dominant species in all tree and herb layers was markedly higher in the preservation area than in the peripheral zones. The species richness indices were significantly higher in the preservation area than in the peripheral zones. Ordination using detrended canonical correspondence analyses showed that the cover of the dominant tree species and rocks could explain the distribution of plant species in the Cartesian space of the ordination. Our results demonstrate that physiognomically designated protected areas match well with ecological data based on diversity indices and ordination analyses and that disturbances in the areas surrounding the ecological landscape of preservation areas can have considerable impacts on plant diversity indices. Hence, the preservation and management of surrounding areas are essential conservation elements for protecting the entire ecological landscape of preservation areas.