• Title/Summary/Keyword: MAXENT

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Consequences of land use change on bird distribution at Sakaerat Environmental Research Station

  • Trisurat, Yongyut;Duengkae, Prateep
    • Journal of Ecology and Environment
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    • v.34 no.2
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    • pp.203-214
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    • 2011
  • The objectives of this research were to predict land-use/land-cover change at the Sakaerat Environmental Research Station (SERS) and to analyze its consequences on the distribution for Black-crested Bulbul (Pycnonotus melanicterus), which is a popular species for bird-watching activity. The Dyna-CLUE model was used to determine land-use allocation between 2008 and 2020 under two scenarios. Trend scenario was a continuation of recent land-use change (2002-2008), while the integrated land-use management scenario aimed to protect 45% of study area under intact forest, rehabilitated forest and reforestation for renewable energy. The maximum entropy model (Maxent), Geographic Information System (GIS) and FRAGSTATS package were used to predict bird occurrence and assess landscape fragmentation indices, respectively. The results revealed that parts of secondary growth, agriculture areas and dry dipterocarp forest close to road networks would be converted to other land use classes, especially eucalyptus plantation. Distance to dry evergreen forest, distance to secondary growth and distance to road were important factors for Black-crested Bulbul distribution because this species prefers to inhabit ecotones between dense forest and open woodland. The predicted for occurrence of Black-crested Bulbul in 2008 covers an area of 3,802 ha and relatively reduces to 3,342 ha in 2020 for trend scenario and to 3,627 ha for integrated-land use management scenario. However, intact habitats would be severely fragmented, which can be noticed by total habitat area, largest patch index and total core area indices, especially under the trend scenario. These consequences are likely to diminish the recreation and education values of the SERS to the public.

Evaluation of Habitat Function of National Park Based on Biodiversity and Habitat Value (보호지역의 지정 및 관리를 위한 국립공원의 서식처 기능 평가 -생물종다양성과 서식처 가치에 기반하여-)

  • Ryu, Ji-Eun;Choi, Yu-Young;Jeon, Seong-Woo;Sung, Hyun-Chan
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.21 no.5
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    • pp.39-60
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    • 2018
  • National parks are designated for the purpose of maintenance, conservation and utilization of different habitats. Therefore, it is necessary to select habitats of a high value as a protected area in order to balance conservation and development. However, the existing national park boundary adjustment and new designation criteria only focused on the endangered species and protected area, without proper evaluation of the habitat value of actual species. Therefore, this study aims to quantitatively evaluate habitat function in terms of biodiversity and habitat value, so that it can be referred to for the designation and boundary adjustment of national parks. We assessed species diversity and habitat values for each of the habitat types, for mammals only, as they are able to choose preferred habitats. In order to evaluate biodiversity, we used Maxent to derive species richness map and used InVEST's Habitat quality model to evaluate habitat value. As a result of evaluation, species richness was high in the national park boundary area. Also, even if the same edge is adjacent to the development area depending on the land cover, the species richness is low. Compared with Wolaksan and Sobaeksan National Park, the species richness and habitat value of the northern area, which is connected with other forests, were higher than those of the southern area where roads were developed. Therefore, it is expected that the use of the result of this study for the national park boundary adjustment and management will enhance the function of the national park as a habitat.

Projecting suitable habitats considering locational characteristics of major wild vegetables and climate change impacts

  • Choi, Jaeyong;Lee, Sanghyuk
    • Korean Journal of Agricultural Science
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    • v.46 no.3
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    • pp.661-670
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    • 2019
  • In this study, we constructed a model of an area where the production and production amount of wild vegetables which are designated as short term income forest products for the whole country are self-sufficient for the representative Eastern Braken fern(Pteridium aquilinum)and Edible aster(Aster scaber). The difference between the existing cultivation site and the model result was examined, and the distribution of the cultivable area was simulated according to the near future climate change by the 2050s. The degree of agreement between the cultivated area and the actual native area was very low at 14.5% for Eastern Braken fern and 12.9% for Edible aster. Using the Maxent model, which has already been proven by many research examples, the cultivation maps through the model can guarantee statistical accuracy by considering many variables. To analyze future location changes, the RCP 4.5 scenario and the RCP 8.5 scenario were applie Edible aster d to predict potential future cultivable areas and compare them to the present. There was no decrease in the cultivable area due to climate change nationwide. However, in the RCP 8.5 scenario for Eastern Braken fern and the RCP 4.5 scenario for Edible aster, declining areas such as Gangwon-do, Jeollabuk-do and Gyeongsangbuk-do showed prominence according to the scenarios. The result of this study suggests that various models can be used for the production of short-term forest productivity maps and it will be used as a climate change impact assessment data for competitive forest products considering the influence of future climate change.

New record of a blood-feeding terrestrial leech, Haemadipsa rjukjuana Oka, 1910 (Haemadipsidae, Arhynchobdellida) on Heuksando Island and possible habitat estimation in the current and future Korean Peninsula using a Maxent model

  • Tae-Yeong Eom;Hyeon-Soo Kim;Yeong-Seok Jo
    • Journal of Species Research
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    • v.12 no.1
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    • pp.109-113
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    • 2023
  • To build a distribution model for Haemadipsa rjukjuana, we collected current occurrences of the species on Heuksando with adjacent islands. Based on current locations and 19 climate variables with DEM (digital elevation model), we built the MaxEnt (maximum entropy) species distribution model for H. rjukjuana in the islands. Then, we applied the MaxEnt model to the mainland of Korea with the current climate condition and topology. In addition to the current distribution scenario, we predicted the future distribution scenarios in Korea by Coupled Model Intercomparison Project Phase 6 (CMIP6) global climate models. Shared Socioeconomic Pathway (SSP) 585 of two CMIP6 models(GISS-E2-1 and INM-CM4-8) from 2040 to 2100 were used for the future projection.

A nationwide analysis of mammalian biodiversity hotspots in South Korea (전국단위의 포유류 생물다양성우수지역 분석 연구)

  • Kim, Jiyeon;Kwon, Hyuksoo;Seo, Changwan;Kim, Myungjin
    • Journal of Environmental Impact Assessment
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    • v.23 no.6
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    • pp.453-465
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    • 2014
  • Hotspots are top sites in terms of species diversity as the most threatened and most diverse sites which have been used to select priority areas for reserves. The purpose of this paper is to identify biodiversity hotspots through analyzing nationwide spatial patterns of species richness and rarity of Korean mammals. Four endangered mammals and eleven common mammals were selected as target species. Environmental variables as model input data were consisted of topography, distance, and vegetation structure etc. and Maxent was used to develop species distribution models for target species. Species richness and rarity were used as index of biodiversity. The results of this study were as follows. Firstly, hotspots of species richness for endangered mammals were in high elevation and steep mountain areas. However, species richness for whole mammals were high in low elevation of mountains. Secondly, distribution pattern of species rarity for endangered mammals were similar as richness. However, hotspots of species rarity for whole mammals were a little different from species richness. Species rarity was high in both low and high elevation of mountain areas. This study will provide the useful information for a biodiversity assessment, a habitat conservation, a national ecological network plan, and the management of protected areas.

Predicting the Potential Habitat, Host Plants, and Geographical Distribution of Pochazia shantungensis (Hemiptera: Ricaniidae) in Korea (갈색날개매미충(Pochazia shantungensis) (Hemiptera: Ricaniidae)의 기주식물, 발생지역 및 잠재서식지 예측)

  • Kim, Dong Eon;Lee, Heejo;Kim, Mi Jeong;Lee, Do-Hun
    • Korean journal of applied entomology
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    • v.54 no.3
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    • pp.179-189
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    • 2015
  • In 2014, surveys were conducted in Korea to study the geographical distribution, host plants, and potential habitats of Pochazia shantungensis. The occurrence of P. shantungensis was confirmed in 43 cities and counties nationwide, and identified for the first time in Gyeongsangbuk-do. P. shantungensis has a wide range of diverse host plants comprising 113 species in 53 families, including crops, fruits, and forest trees. Since the hemipteran was first reported in Korea, 138 species from 62 families have been identified as P. shantungensis host plants. This insect feeds on the following major host plants: Malus pumila, Aralia elata, Styrax japonicus, Salix gracilistyla, Broussonetia kazinoki, Albizia julibrissin, Ailanthus altissima, Castanea crenata, Robinia pseudoacacia, and Cornus officinalis. Potential habitat was analyzed in the present study using the Maxent model with 12 variables (8 climate, 1 land cover, 1 forest type, 1 ecological zoning, and 1 distance). The model ROC AUC was 0.884, indicating a high accuracy. In the present study, precipitation of warmest quater, mean temperature of warmest quarter, forest type, and land cover were the most significant factors affecting P. shantungensis distribution, and habitat.

Prediction of Changes in the Potential Distribution of a Waterfront Alien Plant, Paspalum distichum var. indutum, under Climate Change in the Korean Peninsula (한반도에서 기후변화에 따른 수변 외래식물인 털물참새피의 분포 변화 예측)

  • Cho, Kang-Hyun;Lee, Seung Hyun
    • Ecology and Resilient Infrastructure
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    • v.2 no.3
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    • pp.206-215
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    • 2015
  • Predicting the changes in the potential distribution of invasive alien plants under climate change is an important and challenging task for the conservation of biodiversity and management of the ecosystems in streams and reservoirs. This study explored the effects of climate change on the potential future distribution of Paspalum distichum var. indutum in the Korean Peninsula. P. distichum var. indutum is an invasive grass species that has a profound economic and environmental impact in the waterfronts of freshwater ecosystems. The Maxent model was used to estimate the potential distribution of P. distichum var. indutum under current and future climates. A total of nineteen climatic variables of Worldclim 1.4 were used as current climatic data and future climatic data predicted by HadGEM2-AO with both RCP 2.6 and RCP 8.5 scenarios for 2050. The predicted current distribution of P. distichum var. indutum was almost matched with actual positioning data. Major environmental variables contributing to the potential distribution were precipitation of the warmest quarter, annual mean temperature and mean temperature of the coldest quarter. Our prediction results for 2050 showed an overall reduction in climatic suitability for P. distichum var. indutum in the current distribution area and its expansion to further inland and in a northerly direction. The predictive model used in this study appeared to be powerful for understanding the potential distribution, exploring the effects of climate change on the habitat changes and providing the effective management of the risk of biological invasion by alien plants.

Tree species migration to north and expansion in their habitat under future climate: an analysis of eight tree species Khyber Pakhtunkhwa, Pakistan

  • Muhammad Abdullah Durrani;Rohma Raza;Muhammad Shakil;Shakeel Sabir;Muhammad Danish
    • Journal of Ecology and Environment
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    • v.48 no.1
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    • pp.96-109
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    • 2024
  • Background: Khyber Pakhtunkhwa government initiated the Billion Tree Tsunami Afforestation Project including regeneration and afforestation approaches. An effort was made to assess the distribution characteristics of afforested species under present and future climatic scenarios using ecological niche modelling. For sustainable forest management, landscape ecology can play a significant role. A significant change in the potential distribution of tree species is expected globally with changing climate. Ecological niche modeling provides the valuable information about the current and future distribution of species that can play crucial role in deciding the potential sites for afforestation which can be used by government institutes for afforestation programs. In this context, the potential distribution of 8 tree species, Cedrus deodara, Dalbergia sissoo, Juglans regia, Pinus wallichiana, Eucalyptus camaldulensis, Senegalia modesta, Populus ciliata, and Vachellia nilotica was modeled. Results: Maxent species distribution model was used to predict current and future distribution of tree species using bioclimatic variables along with soil type and elevation. Future climate scenarios, shared socio-economic pathways (SSP)2-4.5 and SSP5-8.5 were considered for the years 2041-2060 and 2081-2100. The model predicted high risk of decreasing potential distribution under SSP2-4.5 and SSP5-8.5 climate change scenarios for years 2041-2060 and 2081-2100, respectively. Recent afforestation conservation sites of these 8 tree species do not fall within their predicted potential habitat for SSP2-4.5 and SSP5-8.5 climate scenarios. Conclusions: Each tree species responded independently in terms of its potential habitat to future climatic conditions. Cedrus deodara and P. ciliata are predicted to migrate to higher altitude towards north in present and future climate scenarios. Habitat of D. sissoo, P. wallichiana, J. regia, and V. nilotica is practiced to be declined in future climate scenarios. Eucalyptus camaldulensis is expected to be expanded its suitability area in future with eastward shift. Senegalia modesta habitat increased in the middle of the century but decreased afterwards in later half of the century. The changing and shifting forests create challenges for sustainable landscapes. Therefore, the study is an attempt to provide management tools for monitoring the climate change-driven shifting of forest landscapes.

Habitat Analysis of Hyla suweonensis in the Breeding Season Using Species Distribution Modeling (종분포모형을 이용한 수원청개구리의 번식기 서식지 분석)

  • Song, Wonkyong
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.18 no.1
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    • pp.71-82
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    • 2015
  • Hyla suweonensis is an endemic species and is designated as the only endangered species I among amphibians in 2012 by the Ministry of Environment, however studies about its habitat are lacking. This study was carried out to analyze habitat of H. suweonensis based on the spatial information using Maxent (Maximum entropy model as a species distribution model. We detected 45 present points until 2013 and 10 environmental variables by literature review for the model. The results showed that $429km^2$ (0.95%) of the study area, which was about 7.75% of the total agricultural area, was high possible habitats of H. suweonensis. The habitat of H. suweonensis was analyzed by over $1km^2$ rice paddy fields that were lower elevations, flat slopes, and not fragmented. The distance from forests and rivers was identified as a factor that affects its habitat possibilities. In order to conserve H. suweonensis, a large area of rice paddy fields should be preserved, and especially the area around forests and rivers would be required more intensive management. In addition, to compensate for degraded habitats of H. suweonensis in urban areas like as Suwon city, considering integrated watershed management strategy could be effective in the perspective of ecological habitat network of H. suweonensis.

Projecting Climate Change Impact on the Potential Distribution of Endemic Plants (Megaleranthis saniculifolia) in Korea (기후변화에 따른 우리나라 특산식물의 잠재적 분포적지 변화 예측 - 모데미풀을 중심으로 -)

  • Lee, Sang-Hyuk;Jung, Huicheul;Choi, Jaeyong
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.15 no.3
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    • pp.75-84
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    • 2012
  • The importance of the genetic value of native plants has been raised recently after the adoption of Nagoya Protocol. In this stream, this research focused on the future distribution of Megaleranthis saniculifolia which has been evolved and adapted to Korean natural environment and classified as an endemic endangered species by IUCN. The distribution of the species in future are projected based on 'present potential distribution area' by adopting SRES (Special Report on Emission Scenarios) A1B climate change scenario using 6 types of GCM (General Circulation Model). The major results of the research are as follows : habitats of Megaleranthis saniculifolia. (1) will be reduced by 44% nation wide; (2) in Chungcheongngnam Do and Jeollanam Do will be the most affected; and (3) in high altitude in Chungcheongbuk Do, Gyunggi Do and Gangwon Do will be relatively less affected.