| 1 | Using multi-source remote sensing data to classify larch plantations in Northeast China and support the development of multi-purpose silviculture显示文摘Due to increasing timber demands, large areas of secondary forests have been converted to larch plantations(LPs) in Northeast China because the secondary forests could not produce timber as much as LPs.However, there are a series of ecological problems such as lower soil fertility, reduced water-holding capacity and acidification of surface runoff water occurring in LPs because of the single-species composition of LPs.Therefore, a guidance on how to transform LPs into larch-broadleaf mixed forests(LBMFs) at a large spatial scale is needed for local foresters.First, Landsat time series data set and SPOT-5 images were combined to map the spatial–temporal distribution of LPs in Northeast China.Then, the topographical characteristics of LPs in 2010 s were determined.Furthermore, three sub-regions of LPs were divided closely linking to their ecosystem services and forest management aims.Finally, detailed information on how to transform the LPs into LBMFs was given according to the three subregions.The results showed that the area of LPs increased during 1980 s and 2010 s, and reached 2.61 million ha in2010 s.Of which, 0.72 million ha(27.6%) and 1.89 million ha(72.4%) LPs distributed in slopes less than 5° and greater than 5°, respectively.Of the LPs(72.4%) in slopes greater than 5°, 48.7 and 23.7% located in downslope(LPs locating at the down slope of adjacent secondary forests in the same aspect) and upslope(LPs locating at the up slope of adjacent secondary forests in the same aspect), respectively; 0.10 million ha(3.8%) located in slopes greater than 25°.The LPs were divided into Sub-Regions-Ⅰ, Ⅱ, Ⅲ according to slopes.For Sub-region-I(top role is to produce timber), self-fertilizing shrub species can be introduced after clean cutting for young-aged LPs, and release thinning can be applied for middle-aged LPs, fast growth thinning for near-matured LPs, and clear cutting for matured LPs.For Sub-Region-Ⅱ(the priority is to provide water conservation combined with timber production), the LPs should be induced into LBMFs.The LPs located the downslope positions in Sub-Region-Ⅱ can be transformed to LBMFs by natural regeneration of broadleaved tree species after thinning because of enough seed sources of broadleaved tree species from the secondary forests locating the upslope positions.The LPs located the upslope positions or the region where seed sources of broadleaved tree species are unavailable in Sub-Region-Ⅱ must be induced to LBMFs by artificial regeneration.For Sub-Region-Ⅲ(the preference is only for water conservation because the slope is greater than 25°), the LPs should be particularly protected from intensive disturbances, and induced into LBMFs by natural regeneration. | Guiduo Shang Jiaojun Zhu Tian Gao Xiao Zheng Jinxin Zhang | 2018 | Journal of Forestry Research2018，29，4： | 1 |
| 2 | Land use and above-ground biomass changes in a mountain ecosystem,northern Thailand显示文摘The conversion of forests into agricultural lands is a major cause of deforestation,particularly in the mountain ecosystems of northern Thailand.It results in a rapid loss of biological diversity of both flora and fauna.In addition,the above-ground biomass(AGB),which can be a major source of carbon storage,is also decreased.This study aimed to predict the AGB in Doi Suthep-Pui National Park,Chiang Mai province,based on land-use/land cover(LULC)changes from 2000 to 2030.Landsat-5 TM(2000)and Landsat-8 TM(2015)satellite images were analyzed to predict LULC changes to 2030.Temporary plots(30 m 930 m)were established in each LULC type for AGB analysis;trees with diameters at breast height≥4.5 cm were identified and measured.AGB of all LULC types were analyzed based on specific allometric equations of each type.The results show that area of forest and nonforested areas fluctuated during the study period.Through the first 15 years(2000–2015),5%(2.9 km^2)of forest changed to either agriculture or urban lands,especially mixed deciduous forest and lower montane forest.There was a similar trend in the 2030 prediction,showing the effect of forest fragmentation and the resultant high number of patches.Total AGB tended to decrease over the 30-year period from 12.5 to 10.6 t ha^-1 in the first and second periods,respectively.Deforestation was the main factor influencing the loss of AGB(30.6 t ha^-1)related to LULC changes.Furthermore,habitat loss would be expected to result in decreased biological diversity.Consequently,a management plan should be developed to avoid unsustainable land use changes,which may adversely affect human well-being. | Sutheera Hermhuk Aingorn Chaiyes Sathid Thinkampheang Noppakun Danrad Dokrak Marod | 2020 | Journal of Forestry Research2020，31，5： | 0 |
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