Knowledge on the potential suitability of tree species to the site is very important for forest management planning.Natural forest distribution provides a good reference for afforestation and forest restoration.In thi...Knowledge on the potential suitability of tree species to the site is very important for forest management planning.Natural forest distribution provides a good reference for afforestation and forest restoration.In this study,we developed species distribution model(SDM)for 16 major tree species with 2,825 permanent sample plots with natural origin from Chinese National Forest Inventory data collected in Jilin Province using the Maxent model.Three types of environmental factors including bioclimate,soil and topography with a total of 33 variables were tested as the input.The values of area under the curve(AUC,one of the receiver operating characteristics of the Maxent model)in the training and test datasets were between 0.784 and 0.968,indicating that the prediction results were quite reliable.The environmental factors affecting the distribution of species were ranked in terms of their importance to the species distribution.Generally,the climatic factors had the greatest contribution,which included mean diurnal range,annual mean temperature,temperature annual range,and iosthermality.But the main environmental factors varied with tree species.Distribution suitability maps under current(1950-2000)and future climate scenarios(CCSM4-RCP 2.6 and RCP 6.0 during 2050)were produced for 16 major tree species in Jilin Province using the model developed.The predicted current and future ranges of habitat suitability of the 16 tree species are likely to be positively and negatively affected by future climate.Seven tree species were found to benefit from future climate including B etula costata,Fraxinus mandshurica,Juglans mandshurica,Phellodendron amurense,Populus ussuriensis,Quercus mongolica and Ulmus pumila;five tree species will experience decline in their suitable habitat including B.platyphylla,Tilia mongolica,Picea asperata,Pinus sylvestris,Pinus koraiensis;and four(Salix koreensis,Abies fabri,Pinus densiflora and Larix olgensis)showed the inconsistency under RCP 2.6 and RCP 6.0 scenarios.The maps of the habitat suitability can be used as a basis for afforestation and forest restoration in northeastern China.The SDMs could be a potential tool for forest management planning.展开更多
It is increasingly relevant to study the effects of climate change on species habitats. Using a maximum entropy model, 22 environmental factors with significant effects on sorghum habitat distribution in China were se...It is increasingly relevant to study the effects of climate change on species habitats. Using a maximum entropy model, 22 environmental factors with significant effects on sorghum habitat distribution in China were selected to predict the potential habitat distribution of sorghum in China. The potential distribution of sorghum under baseline climate conditions and future climate conditions (2050s and 2070s) under two climate change scenarios, RCP4.5 and RCP8.5, were simulated, and the receiver operating curve under the accuracy of the model was evaluated using the area under the receiver operating curve (AUC). The results showed that the maximum entropy model predicted the potential sorghum habitat distribution with high accuracy, with Bio2 (monthly mean diurnal temperature difference), Bio6 (minimum temperature in the coldest month), and Bio13 (rainfall in the wettest month) as the main climatic factors affecting sorghum distribution among the 22 environmental factors. Under the baseline climate conditions, potential sorghum habitats are mainly distributed in the southwest, central, and east China. Over time, the potential sorghum habitat expanded into northern and southern China, with significant additions and negligible decreases in potential sorghum habitat in the study area, and a significant increase in total area, with the RCP8.5 scenario adding much more area than the RCP4.5 scenario.展开更多
Incorporating private and working lands into protected area networks could mitigate the isolation state of protected areas(PAs) and improve the efficiency of conservation.But how to select patches of land for conserva...Incorporating private and working lands into protected area networks could mitigate the isolation state of protected areas(PAs) and improve the efficiency of conservation.But how to select patches of land for conservation is still a troublesome issue.In this study, the MaxEnt model and irreplaceability index were applied to guide marsh conservation in the Nenjiang River Basin, Northeast China.According to the high accuracy of the MaxEnt model predictions(i.e., the average AUC value = 0.933), the Wuyuer River and Zhalong marshes in the downstream reaches of Wuyuer River are the optimal habitat for the Red-crowned crane and migratory waterfowls.There are 22 marsh patches selected by the patch irreplaceability index for conservation, of which 12 patches had been included in the current network of protected areas.The other 10 patches of marsh(amounting to 1096 km^2) far from human disturbances with high NDVI(up to 0.8) and close distance to water(less than 100 m), which are excluded from the existing network of PAs, should be implemented conservation easement programs to improve the protection efficiency of conservation.Specifically, the marshes at Taha, Tangchi, and Lamadian should be given priority for conservation and restoration to reintroduce migratory waterfowls, as this would lessen the current isolation state of the Zhalong National Nature Reserve.展开更多
【目的】研究香料烟在云南的气候适生区,为其合理种植提供理论依据。【方法】使用ArcGIS将气候数据结合地形校正进行协同克里金插值,利用最大熵(maximum entropy,MaxEnt)模型筛选影响香料烟分布的气象因子,最后使用ArcGIS对云南省香料...【目的】研究香料烟在云南的气候适生区,为其合理种植提供理论依据。【方法】使用ArcGIS将气候数据结合地形校正进行协同克里金插值,利用最大熵(maximum entropy,MaxEnt)模型筛选影响香料烟分布的气象因子,最后使用ArcGIS对云南省香料烟的气候适生区进行评价。【结果】MaxEnt模型的曲线下面积(the area under curve,AUC)值为0.993,可精准预测云南省香料烟的气候适生区。影响香料烟在云南省分布的气象因子为2月降雨量、1月日照时间、3月日照时间、3月平均气温、3月降雨量、4月降雨量、1月降雨量、2月日照时间和4月最高气温。香料烟在云南省的最适宜种植区(四级适生区)主要分布在保山、德宏和临沧;适宜种植区(三级适生区)主要分布在保山、德宏、临沧、玉溪、楚雄和大理。MaxEnt模型预测结果与香料烟种植区拟合度较高,其种植区主要分布在四级和三级适生区,极少数分布在二级和一级适生区。【结论】云南省适合种植香料烟的地区主要在西南部,适宜种植区主要为沿怒江、澜沧江、黑惠江及其支流的干热河谷地区。2月降雨量、1月日照时间、3月日照时间和3月平均气温是影响香料烟在云南种植的主要气象因子。展开更多
瓜类细菌性果斑病(bacterial fruit blotch)是瓜类作物上重要的种传细菌性病害,病原菌为西瓜噬酸菌Acidovorax citrulli。我国是全球西甜瓜的主要生产区。近年来,瓜类细菌性果斑病的频繁发生已严重影响我国西甜瓜产业的健康发展。为明...瓜类细菌性果斑病(bacterial fruit blotch)是瓜类作物上重要的种传细菌性病害,病原菌为西瓜噬酸菌Acidovorax citrulli。我国是全球西甜瓜的主要生产区。近年来,瓜类细菌性果斑病的频繁发生已严重影响我国西甜瓜产业的健康发展。为明确瓜类细菌性果斑病在我国的适生性,根据其在全球的最新分布数据,本研究利用MaxEnt模型结合ArcGIS软件预测了瓜类细菌性果斑病在我国的潜在地理分布。结果表明,MaxEnt模型的平均AUC(area under curve,AUC)值均大于0.9,预测结果的准确性较高。在历史气候条件下,瓜类细菌性果斑病适生区分布广泛,主要包括华中、华南和华东地区,以及部分华北、东北地区,占我国面积的47.36%。影响瓜类细菌性果斑病在我国潜在分布区域的主要气候因子包括最热月份最高温度、月平均昼夜温差、最干月份降水量和最干季平均温度。未来气候情景无论是低环境强迫还是高环境强迫,适生区面积均呈现增长的趋势,预示着随着气候的变化,瓜类细菌性果斑病在我国发生的风险不断增加,因此建议应加强检疫监测和防控,严防其扩散。展开更多
基金supported by the forestry public welfare scientific research project(Grant No.201504303)。
文摘Knowledge on the potential suitability of tree species to the site is very important for forest management planning.Natural forest distribution provides a good reference for afforestation and forest restoration.In this study,we developed species distribution model(SDM)for 16 major tree species with 2,825 permanent sample plots with natural origin from Chinese National Forest Inventory data collected in Jilin Province using the Maxent model.Three types of environmental factors including bioclimate,soil and topography with a total of 33 variables were tested as the input.The values of area under the curve(AUC,one of the receiver operating characteristics of the Maxent model)in the training and test datasets were between 0.784 and 0.968,indicating that the prediction results were quite reliable.The environmental factors affecting the distribution of species were ranked in terms of their importance to the species distribution.Generally,the climatic factors had the greatest contribution,which included mean diurnal range,annual mean temperature,temperature annual range,and iosthermality.But the main environmental factors varied with tree species.Distribution suitability maps under current(1950-2000)and future climate scenarios(CCSM4-RCP 2.6 and RCP 6.0 during 2050)were produced for 16 major tree species in Jilin Province using the model developed.The predicted current and future ranges of habitat suitability of the 16 tree species are likely to be positively and negatively affected by future climate.Seven tree species were found to benefit from future climate including B etula costata,Fraxinus mandshurica,Juglans mandshurica,Phellodendron amurense,Populus ussuriensis,Quercus mongolica and Ulmus pumila;five tree species will experience decline in their suitable habitat including B.platyphylla,Tilia mongolica,Picea asperata,Pinus sylvestris,Pinus koraiensis;and four(Salix koreensis,Abies fabri,Pinus densiflora and Larix olgensis)showed the inconsistency under RCP 2.6 and RCP 6.0 scenarios.The maps of the habitat suitability can be used as a basis for afforestation and forest restoration in northeastern China.The SDMs could be a potential tool for forest management planning.
文摘It is increasingly relevant to study the effects of climate change on species habitats. Using a maximum entropy model, 22 environmental factors with significant effects on sorghum habitat distribution in China were selected to predict the potential habitat distribution of sorghum in China. The potential distribution of sorghum under baseline climate conditions and future climate conditions (2050s and 2070s) under two climate change scenarios, RCP4.5 and RCP8.5, were simulated, and the receiver operating curve under the accuracy of the model was evaluated using the area under the receiver operating curve (AUC). The results showed that the maximum entropy model predicted the potential sorghum habitat distribution with high accuracy, with Bio2 (monthly mean diurnal temperature difference), Bio6 (minimum temperature in the coldest month), and Bio13 (rainfall in the wettest month) as the main climatic factors affecting sorghum distribution among the 22 environmental factors. Under the baseline climate conditions, potential sorghum habitats are mainly distributed in the southwest, central, and east China. Over time, the potential sorghum habitat expanded into northern and southern China, with significant additions and negligible decreases in potential sorghum habitat in the study area, and a significant increase in total area, with the RCP8.5 scenario adding much more area than the RCP4.5 scenario.
基金Under the auspices of National Key Research and Development Program of China(No.2016YFA0600401)the Key Research Program of Frontier Sciences from Chinese Academy of Sciences+1 种基金Fundamental Research Funds in Heilongjiang Provincial Universities(No.135209252,135309359)the Philosophy and Social Sciences Research Plan of Heilongjiang Province(No.16JLC01)
文摘Incorporating private and working lands into protected area networks could mitigate the isolation state of protected areas(PAs) and improve the efficiency of conservation.But how to select patches of land for conservation is still a troublesome issue.In this study, the MaxEnt model and irreplaceability index were applied to guide marsh conservation in the Nenjiang River Basin, Northeast China.According to the high accuracy of the MaxEnt model predictions(i.e., the average AUC value = 0.933), the Wuyuer River and Zhalong marshes in the downstream reaches of Wuyuer River are the optimal habitat for the Red-crowned crane and migratory waterfowls.There are 22 marsh patches selected by the patch irreplaceability index for conservation, of which 12 patches had been included in the current network of protected areas.The other 10 patches of marsh(amounting to 1096 km^2) far from human disturbances with high NDVI(up to 0.8) and close distance to water(less than 100 m), which are excluded from the existing network of PAs, should be implemented conservation easement programs to improve the protection efficiency of conservation.Specifically, the marshes at Taha, Tangchi, and Lamadian should be given priority for conservation and restoration to reintroduce migratory waterfowls, as this would lessen the current isolation state of the Zhalong National Nature Reserve.
文摘【目的】研究香料烟在云南的气候适生区,为其合理种植提供理论依据。【方法】使用ArcGIS将气候数据结合地形校正进行协同克里金插值,利用最大熵(maximum entropy,MaxEnt)模型筛选影响香料烟分布的气象因子,最后使用ArcGIS对云南省香料烟的气候适生区进行评价。【结果】MaxEnt模型的曲线下面积(the area under curve,AUC)值为0.993,可精准预测云南省香料烟的气候适生区。影响香料烟在云南省分布的气象因子为2月降雨量、1月日照时间、3月日照时间、3月平均气温、3月降雨量、4月降雨量、1月降雨量、2月日照时间和4月最高气温。香料烟在云南省的最适宜种植区(四级适生区)主要分布在保山、德宏和临沧;适宜种植区(三级适生区)主要分布在保山、德宏、临沧、玉溪、楚雄和大理。MaxEnt模型预测结果与香料烟种植区拟合度较高,其种植区主要分布在四级和三级适生区,极少数分布在二级和一级适生区。【结论】云南省适合种植香料烟的地区主要在西南部,适宜种植区主要为沿怒江、澜沧江、黑惠江及其支流的干热河谷地区。2月降雨量、1月日照时间、3月日照时间和3月平均气温是影响香料烟在云南种植的主要气象因子。
文摘瓜类细菌性果斑病(bacterial fruit blotch)是瓜类作物上重要的种传细菌性病害,病原菌为西瓜噬酸菌Acidovorax citrulli。我国是全球西甜瓜的主要生产区。近年来,瓜类细菌性果斑病的频繁发生已严重影响我国西甜瓜产业的健康发展。为明确瓜类细菌性果斑病在我国的适生性,根据其在全球的最新分布数据,本研究利用MaxEnt模型结合ArcGIS软件预测了瓜类细菌性果斑病在我国的潜在地理分布。结果表明,MaxEnt模型的平均AUC(area under curve,AUC)值均大于0.9,预测结果的准确性较高。在历史气候条件下,瓜类细菌性果斑病适生区分布广泛,主要包括华中、华南和华东地区,以及部分华北、东北地区,占我国面积的47.36%。影响瓜类细菌性果斑病在我国潜在分布区域的主要气候因子包括最热月份最高温度、月平均昼夜温差、最干月份降水量和最干季平均温度。未来气候情景无论是低环境强迫还是高环境强迫,适生区面积均呈现增长的趋势,预示着随着气候的变化,瓜类细菌性果斑病在我国发生的风险不断增加,因此建议应加强检疫监测和防控,严防其扩散。
文摘构建准确的滑坡预测模型和确定环境因子的贡献程度,对滑坡易发性评价具有重要意义。在以往研究中,最大熵物种分布(maximum entropy model,MaxEnt)模型因其对样本量要求低、预测精度高和可避免模型过度拟合等优点,被广泛运用在生态学领域。以沅陵县为研究区,基于342处滑坡灾害点数据和9个环境变量,分别采用确定性系数(certainty factor,CF)模型、逻辑回归(Logistic)模型和MaxEnt模型对沅陵县进行滑坡易发性分区预测。同时采用刀切法(Jackknife)检验环境因子对预测结果的贡献程度,确定滑坡地质灾害的主要影响因素。结果表明:确定性系数模型、逻辑回归模型和MaxEnt模型的受试者特征曲线(receiver operating characteristic,ROC)下面积(area under the curve,AUC)值分别为0.827、0.803、0.911,3种模型的预测精度均较高,且MaxEnt模型精度最高,表现较好;河流是影响研究区滑坡灾害发生贡献程度最高的环境因子;滑坡灾害主要发育在以河流为中心向外延伸100 m范围内,集中分布在沅江、深溪和兰溪附近。研究能为沅陵县地质灾害易发性评价提供一种新的方法。
