Fire-induced forest loss has substantially increased worldwide over the last decade.In China,the connection between forest loss and frequent fi res on a national scale remains largely unexplored.In this study,we used ...Fire-induced forest loss has substantially increased worldwide over the last decade.In China,the connection between forest loss and frequent fi res on a national scale remains largely unexplored.In this study,we used a data set for a time-series of forest loss from the Global Forest Watch and for a MODIS-derived burned area for 2003–2015 to ascertain variations in forest loss and to explore its relationship with forest fi res(represented by burned areas)at the country-and forest-zone levels.We quantifi ed trends in forest loss during 2003–2015 using linear regression analysis and assessed the relation between forest loss and burned areas using Spearman’s correlation.Forest loss increased signifi cantly(264.8 km 2 a−1;R 2=0.54,p<0.01)throughout China,with an average annual increase of 11.4%during 2003–2015.However,the forest loss trend had extensive spatial heterogeneity.Forest loss increased mainly in the subtropical evergreen broadleaf forest zone(315.0 km 2 a−1;R 2=0.69,p<0.01)and tropical rainforest zone(38.8 km 2 a−1;R 2=0.66,p<0.01),but the loss of forest decreased in the cold temperate deciduous coniferous forest zone(−70.8 km 2 year−1;R 2=0.75,p<0.01)and the temperate deciduous mixed broadleaf and coniferous forest zone(−14.4 km 2 a−1;R 2=0.45,p<0.05).We found that 1.0%of China’s area had a signifi cant positive correlation(r≥0.55,p<0.05)with burned areas and 0.3%had a signifi cant negative correlation(r≤−0.55,p<0.05).In particular,forest loss had a signifi cant positive relationship with the burned area in the cold temperate deciduous coniferous forest zone(16.9% of the lands)and the subtropical evergreen broadleaf forest zone(7.8%).These results provide a basis for future predictions of fi re-induced forest loss in China.展开更多
China has experienced rapid urbanizations with dramatic land cover changes since 1978. Forest loss is one of land cover changes, and it induces various eco-environmental degradation issues. As one of China’s hotspot ...China has experienced rapid urbanizations with dramatic land cover changes since 1978. Forest loss is one of land cover changes, and it induces various eco-environmental degradation issues. As one of China’s hotspot regions, the Guangdong-Hong KongMacao Greater Bay Area(GBA) has undergone a dramatic urban expansion. To better understand forest dynamics and protect forest ecosystem, revealing the processes, patterns and underlying drivers of forest loss is essential. This study focused on the spatiotemporal evolution and potential driving factors of forest loss in the GBA at regional and city level. The Landsat time-series images from 1987 to2017 were used to derive forest, and landscape metrics and geographic information system(GIS) were applied to implement further spatial analysis. The results showed that: 1) 14.86% of the total urban growth area of the GBA was obtained from the forest loss in1987–2017;meanwhile, the forest loss area of the GBA reached 4040.6 km2, of which 25.60%(1034.42 km2) was converted to urban land;2) the percentages of forest loss to urban land in Dongguan(19.14%), Guangzhou(18.35%) and Shenzhen(15.81%) were higher than those in other cities;3) the forest became increasingly fragmented from 1987–2007, and then the fragmentation decreased from2007 to 2017);4) the landscape responses to forest changes varied with the scale;and 5) some forest loss to urban regions moved from low-elevation and gentle-slope terrains to higher-elevation and steep-slope terrains over time, especially in Shenzhen and Hong Kong.Urbanization and industrialization greatly drove forest loss and fragmentation, and, notably, hillside urban land expansion may have contributed to hillside forest loss. The findings will help policy makers in maintaining the stability of forest ecosystems, and provide some new insights into forest management and conservation.展开更多
Conversion of forest land to farmland in the Hyrcanian forest of northern Iran increases the nutrient input, especially the phosphorus（P） nutrient, thus impacting the water quality. Modeling the effect of forest los...Conversion of forest land to farmland in the Hyrcanian forest of northern Iran increases the nutrient input, especially the phosphorus（P） nutrient, thus impacting the water quality. Modeling the effect of forest loss on surface water quality provides valuable information for forest management. This study predicts the future impacts of forest loss between 2010 and 2040 on P loading in the Tajan River watershed at the sub-watershed level. To understand drivers of the land cover, we used Land Change Modeler（LCM） combining with the Soil Water Assessment Tool（SWAT） model to simulate the impacts of land use change on P loading. We characterized priority management areas for locating comprehensive and cost-effective management practices at the sub-watershed level. Results show that agricultural expansion has led to an intense deforestation. During the future period 2010–2040, forest area is expected to decrease by 34,739 hm^2. And the areas of pasture and agriculture are expected to increase by 7668 and 27,071 hm^2, respectively. In most sub-watersheds, P pollution will be intensified with the increase in deforestation by the year 2040. And the P concentration is expected to increase from 0.08 to 2.30 mg/L in all of sub-watersheds by the year 2040. It should be noted that the phosphorous concentration exceeds the American Public Health Association′s water quality standard of 0.2 mg/L for P in drinking water in both current and future scenarios in the Tajan River watershed. Only 30% of sub-watersheds will comply with the water quality standards by the year 2040. The finding of the present study highlights the importance of conserving forest area to maintain a stable water quality.展开更多
Forest loss impacts local climate through biophysical processes.However,our understanding of this impact remains limited due to the neglect of its temporal dynamics.Using a space-and-time scheme that incorporates a ch...Forest loss impacts local climate through biophysical processes.However,our understanding of this impact remains limited due to the neglect of its temporal dynamics.Using a space-and-time scheme that incorporates a change-detection method,we assess the dynamics of land surface temperature(LST)responses to various forest-loss types.Globally,LST increased by 0.12 K one year after forest loss,followed by a decreasing trend of0.14 K per decade.Deforestation driven by commodity production and urbanization results in persistent warming,while forest disturbances such as shifting agriculture,forestry,and fire trigger diverse response dynamics with significant spatial variation due to differences in subsequent vegetation recovery.These disturbances cause attenuated warming in low and mid-latitudes,while,in the boreal zone,contrasting dynamics are observed:shifting agriculture causes attenuated cooling,whereas forestry and fire result in enhanced cooling.In addition to amplifying the amplitude of the LST seasonal cycle,forest loss also shifts the seasonal phase,which has not been previously reported.These findings demonstrate that climate feedback from forest loss is climate specific,loss-type dependent,and time varying,providing new insights for the development of local climate policies.展开更多
After forest fire, it is very needed to locate fire position and assess the loss of forest resources. In this paper, a method of burned forest assessment with satellite remote sensing data and over-laying techniques i...After forest fire, it is very needed to locate fire position and assess the loss of forest resources. In this paper, a method of burned forest assessment with satellite remote sensing data and over-laying techniques is discussed and used in the assessment of the burned forest in Malin Forest Farm after the large forest fire of May, 1987.展开更多
Forest ecosystems are vital not only for the ecosystem and biogeochemical processes, but also for the livelihood of forest dependent communities for which its continual existence is a necessity. This study explored th...Forest ecosystems are vital not only for the ecosystem and biogeochemical processes, but also for the livelihood of forest dependent communities for which its continual existence is a necessity. This study explored the pattern of forest use in the hinterlands of the Niger Delta and sought to elucidate the drivers of forest loss and how the ownership and management of the forest plots influenced the changes in the forest ecosystem. Ecosystem services reduction and forest loss/degradation were found to be increasing over the years due to crude oil activities, urbanization/developments, population increase, agricultural activities and natural causes like flood. While each factor contributed to forest loss directly and indirectly, and varied from community to community, agricultural activities and population growth were responsible for most of the losses across the landscape. Even though agricultural activities were essential and thrived in the region, sustainable forest (land) uses could have reduced the associated implications of such land uses;but this was however hampered by the farming practises (shifting cultivation) across most of the communities. Lack of proper, effective and sustainable forest management structures, poor individual commitment and monitoring of forest activities were found to encourage forest loss at different spatial scales. Provision of alternative sources of livelihood and ensuring that suitable guidelines on forest abstraction and harvest are enforced across the region, are steps to promoting biodiversity conservation and resource management.展开更多
基金We are grateful to Zhihua Liu for his constructive comments to improve the manuscript.
文摘Fire-induced forest loss has substantially increased worldwide over the last decade.In China,the connection between forest loss and frequent fi res on a national scale remains largely unexplored.In this study,we used a data set for a time-series of forest loss from the Global Forest Watch and for a MODIS-derived burned area for 2003–2015 to ascertain variations in forest loss and to explore its relationship with forest fi res(represented by burned areas)at the country-and forest-zone levels.We quantifi ed trends in forest loss during 2003–2015 using linear regression analysis and assessed the relation between forest loss and burned areas using Spearman’s correlation.Forest loss increased signifi cantly(264.8 km 2 a−1;R 2=0.54,p<0.01)throughout China,with an average annual increase of 11.4%during 2003–2015.However,the forest loss trend had extensive spatial heterogeneity.Forest loss increased mainly in the subtropical evergreen broadleaf forest zone(315.0 km 2 a−1;R 2=0.69,p<0.01)and tropical rainforest zone(38.8 km 2 a−1;R 2=0.66,p<0.01),but the loss of forest decreased in the cold temperate deciduous coniferous forest zone(−70.8 km 2 year−1;R 2=0.75,p<0.01)and the temperate deciduous mixed broadleaf and coniferous forest zone(−14.4 km 2 a−1;R 2=0.45,p<0.05).We found that 1.0%of China’s area had a signifi cant positive correlation(r≥0.55,p<0.05)with burned areas and 0.3%had a signifi cant negative correlation(r≤−0.55,p<0.05).In particular,forest loss had a signifi cant positive relationship with the burned area in the cold temperate deciduous coniferous forest zone(16.9% of the lands)and the subtropical evergreen broadleaf forest zone(7.8%).These results provide a basis for future predictions of fi re-induced forest loss in China.
基金Under the auspices of National Natural Science Foundation of China(No.41890854)Basic Research Program of Shenzhen Science and Technology Innovation Committee(No.JCYJ20180507182022554)+3 种基金National Key R&D Program of China(No.2017YFC0506200)National Natural Science Foundation of China(No.7181101150)National Natural Science Foundation of China(No.41901248)Shenzhen Future Industry Development Funding Program(No.201507211219247860)。
文摘China has experienced rapid urbanizations with dramatic land cover changes since 1978. Forest loss is one of land cover changes, and it induces various eco-environmental degradation issues. As one of China’s hotspot regions, the Guangdong-Hong KongMacao Greater Bay Area(GBA) has undergone a dramatic urban expansion. To better understand forest dynamics and protect forest ecosystem, revealing the processes, patterns and underlying drivers of forest loss is essential. This study focused on the spatiotemporal evolution and potential driving factors of forest loss in the GBA at regional and city level. The Landsat time-series images from 1987 to2017 were used to derive forest, and landscape metrics and geographic information system(GIS) were applied to implement further spatial analysis. The results showed that: 1) 14.86% of the total urban growth area of the GBA was obtained from the forest loss in1987–2017;meanwhile, the forest loss area of the GBA reached 4040.6 km2, of which 25.60%(1034.42 km2) was converted to urban land;2) the percentages of forest loss to urban land in Dongguan(19.14%), Guangzhou(18.35%) and Shenzhen(15.81%) were higher than those in other cities;3) the forest became increasingly fragmented from 1987–2007, and then the fragmentation decreased from2007 to 2017);4) the landscape responses to forest changes varied with the scale;and 5) some forest loss to urban regions moved from low-elevation and gentle-slope terrains to higher-elevation and steep-slope terrains over time, especially in Shenzhen and Hong Kong.Urbanization and industrialization greatly drove forest loss and fragmentation, and, notably, hillside urban land expansion may have contributed to hillside forest loss. The findings will help policy makers in maintaining the stability of forest ecosystems, and provide some new insights into forest management and conservation.
基金The Modares Tarbiat University of Iran funded this work
文摘Conversion of forest land to farmland in the Hyrcanian forest of northern Iran increases the nutrient input, especially the phosphorus（P） nutrient, thus impacting the water quality. Modeling the effect of forest loss on surface water quality provides valuable information for forest management. This study predicts the future impacts of forest loss between 2010 and 2040 on P loading in the Tajan River watershed at the sub-watershed level. To understand drivers of the land cover, we used Land Change Modeler（LCM） combining with the Soil Water Assessment Tool（SWAT） model to simulate the impacts of land use change on P loading. We characterized priority management areas for locating comprehensive and cost-effective management practices at the sub-watershed level. Results show that agricultural expansion has led to an intense deforestation. During the future period 2010–2040, forest area is expected to decrease by 34,739 hm^2. And the areas of pasture and agriculture are expected to increase by 7668 and 27,071 hm^2, respectively. In most sub-watersheds, P pollution will be intensified with the increase in deforestation by the year 2040. And the P concentration is expected to increase from 0.08 to 2.30 mg/L in all of sub-watersheds by the year 2040. It should be noted that the phosphorous concentration exceeds the American Public Health Association′s water quality standard of 0.2 mg/L for P in drinking water in both current and future scenarios in the Tajan River watershed. Only 30% of sub-watersheds will comply with the water quality standards by the year 2040. The finding of the present study highlights the importance of conserving forest area to maintain a stable water quality.
基金support from the National Natural Science Foundation of China(grant no.41921001)the China Postdoctoral Science Foundation(certificate number 2023M733812)。
文摘Forest loss impacts local climate through biophysical processes.However,our understanding of this impact remains limited due to the neglect of its temporal dynamics.Using a space-and-time scheme that incorporates a change-detection method,we assess the dynamics of land surface temperature(LST)responses to various forest-loss types.Globally,LST increased by 0.12 K one year after forest loss,followed by a decreasing trend of0.14 K per decade.Deforestation driven by commodity production and urbanization results in persistent warming,while forest disturbances such as shifting agriculture,forestry,and fire trigger diverse response dynamics with significant spatial variation due to differences in subsequent vegetation recovery.These disturbances cause attenuated warming in low and mid-latitudes,while,in the boreal zone,contrasting dynamics are observed:shifting agriculture causes attenuated cooling,whereas forestry and fire result in enhanced cooling.In addition to amplifying the amplitude of the LST seasonal cycle,forest loss also shifts the seasonal phase,which has not been previously reported.These findings demonstrate that climate feedback from forest loss is climate specific,loss-type dependent,and time varying,providing new insights for the development of local climate policies.
文摘After forest fire, it is very needed to locate fire position and assess the loss of forest resources. In this paper, a method of burned forest assessment with satellite remote sensing data and over-laying techniques is discussed and used in the assessment of the burned forest in Malin Forest Farm after the large forest fire of May, 1987.
文摘Forest ecosystems are vital not only for the ecosystem and biogeochemical processes, but also for the livelihood of forest dependent communities for which its continual existence is a necessity. This study explored the pattern of forest use in the hinterlands of the Niger Delta and sought to elucidate the drivers of forest loss and how the ownership and management of the forest plots influenced the changes in the forest ecosystem. Ecosystem services reduction and forest loss/degradation were found to be increasing over the years due to crude oil activities, urbanization/developments, population increase, agricultural activities and natural causes like flood. While each factor contributed to forest loss directly and indirectly, and varied from community to community, agricultural activities and population growth were responsible for most of the losses across the landscape. Even though agricultural activities were essential and thrived in the region, sustainable forest (land) uses could have reduced the associated implications of such land uses;but this was however hampered by the farming practises (shifting cultivation) across most of the communities. Lack of proper, effective and sustainable forest management structures, poor individual commitment and monitoring of forest activities were found to encourage forest loss at different spatial scales. Provision of alternative sources of livelihood and ensuring that suitable guidelines on forest abstraction and harvest are enforced across the region, are steps to promoting biodiversity conservation and resource management.
