• Title/Summary/Keyword: Species Distribution

Search Result 165, Processing Time 0.158 seconds

A Study on the Species Distribution Modeling using National Ecosystem Survey Data (전국자연환경조사 자료를 이용한 종분포모형 연구)

  • Kim, Jiyeon;Seo, Changwan;Kwon, Hyuksoo;Ryu, Jieun;Kim, Myungjin
    • Journal of Environmental Impact Assessment
    • /
    • v.21 no.4
    • /
    • pp.593-607
    • /
    • 2012
  • The Ministry of Environment have started the 'National Ecosystem Survey' since 1986. It has been carried out nationwide every ten years as the largest survey project in Korea. The second one and the third one produced the GIS-based inventory of species. Three survey methods were different from each other. There were few studies for species distribution using national survey data in Korea. The purposes of this study are to test species distribution models for finding the most suitable modeling methods for the National Ecosystem Survey data and to investigate the modeling results according to survey methods and taxonominal group. Occurrence data of nine species were extracted from the National Ecosystem Survey by taxonomical group (plant, mammal, and bird). Plants are Korean winter hazel (Corylopsis coreana), Iris odaesanensis (Iris odaesanensis), and Berchemia (Berchemia berchemiaefolia). Mammals are Korean Goral (Nemorhaedus goral), Marten (Martes flavigula koreana), and Leopard cat (Felis bengalensis). Birds are Black Woodpecker (Dryocopus martius), Eagle Owl (Bubo Bubo), and Common Buzzard (Buteo buteo). Environmental variables consisted of climate, topography, soil and vegetation structure. Two modeling methods (GAM, Maxent) were tested across nine species, and predictive species maps of target species were produced. The results of this study were as follows. Firstly, Maxent showed similar 5 cross-validated AUC with GAM. Maxent is more useful model to develop than GAM because National Ecosystem Survey data has presence-only data. Therefore, Maxent is more useful species distribution model for National Ecosystem Survey data. Secondly, the modeling results between the second and third survey methods showed sometimes different because of each different surveying methods. Therefore, we need to combine two data for producing a reasonable result. Lastly, modeling result showed different predicted distribution pattern by taxonominal group. These results should be considered if we want to develop a species distribution model using the National Ecosystem Survey and apply it to a nationwide biodiversity research.

Pattern of Species Distribution along Environmental Variables in Two Different Forest Beat of Raghunandan Reserve Forest of Habiganj

  • Hosen, Md. Shahadat;Ahamed, Md. Saleh
    • Journal of Forest and Environmental Science
    • /
    • v.33 no.4
    • /
    • pp.257-269
    • /
    • 2017
  • The study has piloted to find the Pattern of species distribution along environmental variables and disturbance in Raghunandan Reserve Forest. Shaltila and Shahapur beat of Raghunandan Hill Reserve Forest are situated in Chunarughat sub-district of Habiganj district between $24^{\circ}5^{\prime}-24^{\circ}10^{\prime}N$ and $91^{\circ}25^{\prime}-91^{\circ}30^{\prime}E$ under the Sylhet Forest Division. The Environmental variable and vegetation data were collected from 30 sample plots from each forest beat by using arbitrary sampling without preconceived bias. 51 species were found from Shaltila and 34 species found in Shahapur forest beat. Thus the dataset continued with total 85 species in 60 samples. To determine the relationships between tree species distribution and environmental variables, Canonical Correspondence Analysis (CCA) ordination method were performed separately for two forest beat. In CCA ordination, tree species showed significant variation along environmental gradients in terms of soil organic matter and disturbances (p<0.05) in the case of Shaltila forest. Potassium has a significant relationship with axis 1 and axis 2 in this forest. But Shahapur forest showed no significant relationship between species and environmental variables. Phosphorus has a significantly negative relationship with axis 2 in this forest. Disturbance played as a critical role of this forest thus influencing the distribution of species. The study showed that the distributions of tree species are strongly influenced by disturbance and organic matter in Shaltila and Shahapur forest beat showed no significant relationship between species and environmental variables. Future research should be included more environmental variables with larger study area that identify the most important environmental forces which will drive by species distribution findings in this forest.

Environmental features of the distribution areas and climate sensitivity assesment of Korean Fir and Khinghan Fir (구상나무와 분비나무분포지의 환경 특성 및 기후변화 민감성 평가)

  • Park, Hyun-Chul;Lee, Jung-Hwan;Lee, Gwan-Gyu;Um, Gi-Jeung
    • Journal of Environmental Impact Assessment
    • /
    • v.24 no.3
    • /
    • pp.260-277
    • /
    • 2015
  • The object of this study was the climate change sensitivity assessment of Korean Fir and Khinghan Fir as a representative subalpine plant in South Korea. Using species distribution models, we predicted the probability of current and future species distribution. According to this study, potential distribution that have been predicted based on the threshold (MTSS) is, Khinghan Fir was higher loss rate than Korean Fir. And in the climate change sensitivity assessment using the scalar sensitivity weight ($W_{is}$), $W_{is}$ of Korean Fir was higher relatively than the sensitivity of Khinghan Fir. When using the species distribution models as shown in this study may vary depending on the probability of presence data and spatial variables. Therefore should be prior decision studies on the ecological environment of the study species. Based on this study, if it is domestic applicable climate change sensitivity assessment method is developed. it would be important decision-making to climate change and biological diversity of adaptation policy.

Distributional Pattern of Tree Species in Response to Soil Variables in a Semi Natural Tropical Forest of Bangladesh

  • Ara, Saida Hossain;Limon, Mahedi Hasan;Kibria, Mohammad Golam
    • Journal of Forest and Environmental Science
    • /
    • v.37 no.1
    • /
    • pp.14-24
    • /
    • 2021
  • A plant community is a group of populations that coexist in space and interact directly or indirectly with the environment. In this paper, we determined the pattern of tree species composition in response to soil variables in Khadimnagar National Park (KNP), which is one of the least studied tropical forests in Bangladesh. Soil and vegetation data were collected from 71 sample plots. Canonical Correspondence Analysis (CCA) with associated Monte Carlo permutation tests (499 permutations) was carried out to determine the most significant soil variable and to explore the relationship between tree species distribution and soil variables. Soil pH and clay content (pH with p<0.01 and Clay content with p<0.05) were the most significant variables that influence the overall tree species distribution in KNP. Soil pH is related to the distribution and abundance of Syzygium grande and Magnolia champaca, which were mostly found and dominant species in KNP. Some species were correlated with clay content such as Artocarpus chaplasha and Cassia siamea. These observations suggest that both the physico-chemical properties of soil play a major role in shaping the tree distribution in KNP. Hence, these soil properties should take into account for any tree conservation strategy in this forest.

Effectiveness of Sensitivity Analysis for Parameter Selection in CLIMEX Modeling of Metcalfa pruinosa Distribution

  • Byeon, Dae-hyeon;Jung, Sunghoon;Mo, Changyeun;Lee, Wang-Hee
    • Journal of Biosystems Engineering
    • /
    • v.43 no.4
    • /
    • pp.410-419
    • /
    • 2018
  • Purpose: CLIMEX, a species distribution modeling tool, includes various types of parameters representing climatic conditions; the estimation of these parameters directly determines the model accuracy. In this study, we investigated the sensitivity of parameters for the climatic suitability calculated by CLIMEX for Metcalfa pruinosa in South Korea. Methods: We first changed 12 parameters and identified the three significant parameters that considerably affected the CLIMEX simulation response. Results: The result indicated that the simulation was highly sensitive to changes in lower optimal temperatures, lower soil moisture thresholds, and cold stress accumulation rate based on the sensitivity index, suggesting that these were the fundamental parameters to be used for fitting the simulation into the actual distribution. Conclusion: Sensitivity analysis is effective for estimating parameter values, and selecting the most important parameters for improving model accuracy.

Characteristic Species Distribution of the Baekdoo Great Mountain Chain at Kangwon Province, korea (백두대간계 중 강원도 지역의 종 분포 특성)

  • 정연숙
    • The Korean Journal of Ecology
    • /
    • v.21 no.1
    • /
    • pp.105-112
    • /
    • 1998
  • Characteristics of species distribution in the Baekdoo Great Mountain Chain of Kangwon Province were discussed. Resulting from Detrending Correspondence Analysis based on the floristic composition of 48 mountains, the mountains of the Baekdoo chain tended to aggregate on DCA axis. it represented that there was the peculiar floristic composition of the Baekdoo chain separated from the other mountains. High altitude, longitude near the East Sea and large number of vascular species were main factors for the distribution pattern. And exponential relationships between endemic rare species and number of species were clarified. Even though the regions of the Baekdoo Great Mountain Chain had been conserved relatively well, many regions have been faced to be disturbed for tourism, agriculture, forestry, livestock industry and mining since the local autonomy. Thusm, the necessity for the establishment of large area network through the connection of scattered protected areas in the Baekdoo Great Mountain Chain was suggested. it would play a role as a core of nature conservation to sustain species diversity in Korea.

  • PDF

A COMPUTATIONAL ANALYSIS OF FINITE RATE CHEMICALLY REACTING FLOW BY USING UPWIND N-S METHOD

  • Seo J. I.;Kwon C. O.;Song D. J.
    • 한국전산유체공학회:학술대회논문집
    • /
    • /
    • pp.166-171
    • /
    • 2000
  • A two-dimensional/axisymmetric CSCM upwind flux difference splitting Wavier-Stokes method has been developed to study the finite rate chemically react-ing invisicd and viscous hypersonic flows over blunt-body. A upwind method was chosen due to its robustness in capturing the strong bow shock waves. For the nonequilibrium chemically reacting air, NS-I species conservation equations were strongly coupled with flowfield equations through convection and species production terms. The nonequilibrium wall pressure and heat transfer rate distributions along the vehicle were compared with those from equilibrium and perfect gas calculations. The nonequilibrium species distribution shows the reduced concentrations of O and N species when compared with equilibrium species distribution. The solutions resolved strong bow shock waves md heat transfer rate very accurately when compared with central difference schemes.

  • PDF

Species Distribution Modeling of Endangered Mammals for Ecosystem Services Valuation - Focused on National Ecosystem Survey Data - (생태계 서비스 가치평가를 위한 멸종위기 포유류의 종분포 연구 - 전국자연환경조사 자료를 중심으로 -)

  • Jeon, Seong Woo;Kim, Jaeuk;Jung, Huicheul;Lee, Woo-Kyun;Kim, Joon-Soon
    • Journal of the Korean Society of Environmental Restoration Technology
    • /
    • v.17 no.1
    • /
    • pp.111-122
    • /
    • 2014
  • The provided habitat of many services from natural capital is important. But because most ecosystem services tools qualitatively evaluated biodiversity or habitat quality, this study quantitatively analyzed those aspects using the species distribution model (MaxEnt). This study used location point data of the goat(Naemorhedus caudatus), marten(Martes flavigula), leopard cat(Prionailurus bengalensis), flying squirrel(Pteromys volans aluco) and otter(Lutra lutra) from the 3rd National Ecosystem Survey. Input data utilized DEM, landcover classification maps, Forest-types map and digital topographic maps. This study generated the MaxEnt model, randomly setting 70% of the presences as training data, with the remaining 30% used as test data, and ran five cross-validated replicates for each model. The threshold indicating maximum training sensitivity plus specificity was considered as a more robust approach, so this study used it to conduct the distribution into presence(1)-absence(0) predictions and totalled up a value of 5 times for uncertainty reduction. The test data's ROC curve of endangered mammals was as follows: growing down goat(0.896), otter(0.857), flying squirrel(0.738), marten(0.725), and leopard cat(0.629). This study was divided into two groups based on habitat: the first group consisted of the goat, marten, leopard cat and flying squirrel in the forest; and the second group consisted of the otter in the river. More than 60 percent of endangered mammals' distribution probability were 56.9% in the forest and 12.7% in the river. A future study is needed to conduct other species' distribution modeling exclusive of mammals and to develop a collection method of field survey data.