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Characterizing the effects of climate change on short-term post-disturbance Forest recovery in southern China from Landsat time-series observations(1988-2016)

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Frontiers of Earth Science 2020年第4期14卷 816-827页

作者： Fangyan Zhu Heng Wang Mingshi Li Jiaojiao Diao Wenjuan Shen Yali Zhang Hongji Wu College of forestry Nanjing Forestry UniversityNanjing210037China Co-Innovation Center for Sustainable forestry in Southern China Nanjing Forestry UniversityNanjing210037China

Climate change,a recognized critical environmental issue,plays an important role in regulating the structure and function of forest ecosystems by altering forest disturbance and recovery regimes.This research focused on exploring the statistical relationships between meteorological and topographic variables and the recovery characteristics following disturbance of plantation forests in southern China.We used long-term Landsat images and the vegetation change tracker algorithm to map forest disturbance and recovery events in the study area from 1988 to 2016.Stepwise multiple linear regression(MLR),random forest(RF)regression,and support vector machine(SVM)regression were used in conjunction with climate variables and topographic factors to model short-term Forest recovery using the normalized difference vegetation index(NDVI).The results demonstrated that the regenerating forests were sensitive to the variation in temperature.The fitted results suggested that the relationship between the NDVI values of the forest areas and the post-disturbance climatic and topographic factors differed in regression algorithms.The RF regression yielded the best performance with an R2 value of 0.7348 for the validation accuracy.This indicated that slope and temperature,especially high temperatures,had substantial effects on post-disturbance vegetation recovery in southern China.For other mid-subtropical monsoon regions with intense light and heat and abundant rainfall,the information will also contribute to appropriate decisions for forest managers on Forest recovery measures.Additionally,it is essential to explore the relationships between Forest recovery and climate change of different vegetation types or species for more accurate and targeted Forest recovery strategies.

关键词： climate change forest disturbance Forest recovery vegetation change tracker

Responses of intra-annual runoff to Forest recovery patterns in subtropical China

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Journal of forestry Research 2021年第4期32卷 1479-1488页

作者： Zhipeng Xu Wenfei Liu Qiang Li Jianping Wu Honglang Duan Guomin Huang Yizao Ge Jiangxi Province Key Laboratory for Restoration of Degraded Ecosystems&Watershed Ecohydrology Nanchang Institute of TechnologyNanchang 330099People’s Republic of China Department of Civil Engineering University of Victoria3800 Finnerty RoadVictoriaBC V8P 5C2Canada Yunnan Key Laboratory of Plant Reproductive Adaption and Evolutionary Ecology Yunnan UniversityKunming 650500People’s Republic of China

Forest recovery plays a critical role in regulating eco-hydrological processes in forested watersheds.However,characteristics of the intra-annual runoff variation associated with different Forest recovery patterns remain poorly understood.In this study,three forest change periods were identified,the baseline period(1961-1985),reforestation period(1986-2000)and fruit tree planting period(2001-2016).We selected the magnitude of seasonal runoff(wet and dry seasons)and distribution characteristics,i.e.,non-uniformity coefficient(C_(v)),complete accommodation coefficient(C_(r)),concentration ratio(C_(n)),concentration period(C_(d)),absolute variation ratio(ΔR)and relative variation ratio(C_(max)).The pair-wise approach evaluated the intra-annual runoff variation characteristics between forest change periods.Results indicate that reforestation decreased wet season runoff and increased dry season runoff.In contrast,fruit tree planting increased wet season runoff and had no significant effect on dry season runoff.For intra-annual runoff distribution characteristics,reforestation significantly reduced the C_(v),C_(r),C_(n)and C_(max).Distribution of the intra-annual runoff in the fruit tree planting period was not significantly different from the baseline.We concluded that reforestation reduced the occurance of extreme water conditions in wet and dry seasons and effectively increased the stability of the intra-annual runoff.In contrast,fruit tree planting increased instability and fluctuation of the intra-annual runoff after reforestation.The characteristics of the intra-annual runoff to fruit tree planting was similar to those of the baseline.Therefore,adopting fruit tree planting practices to regulate intra-annual runoff characteristics may not be a practical approach,and impacts of different reforestation practices should be ascertained in our study region.The implications of this study should guide regional land-water management,and this study adds to the understanding of the impacts gained in forest cover on hydrolog

关键词： Intra-annual runoff variation Seasonal runoff Forest recovery Reforestation Fruit tree planting

A chronosequence analysis of Forest recovery on abandoned agricultural fields in Nicaragua

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Journal of forestry Research 2009年第A3期20卷 213-222页

作者： Guillermo Castro Matin Mulualem Tigabu Benigno Gonzalez-Rivas Per Christer Oden Facultad de Recursos Naturales y del Ambiente Universidad Nacional Agraria Apartado posta 453 Managua Nicaragua. Swedish University of Agricultural Sciences Faculty of Forest Sciences Southern Swedish Forest Research Centre Tropical Silviculture and SeedLaboratory PO Box 101 SE-230 53 Alnarp Sweden.

Species composition, diversity and population structure of woody species recovered on three abandoned agricultural fields after 4, 9 and 14 years were characterized. Seedlings, saplings/poles and mature trees were identified and counted in 70 plots of 100 m^2 in each abandoned site. A total of 13, 29 and 22 families represented by 17, 48 and 44 species were registered in 4-, 9- and 14-year-old stands, respectively. There was a shift in dominant species across successional stages. Lonchocarpus acuminatus had the highest importance value in the 4-year old stand, whereas, Myrospermun frutescens, Guazurna ulmifolia and Cordia alliodora had the highest importance value in the 9-year-old-stand and Caesaeria corymbosa, Muntingia calabura, Gliricidia sepium and Tabebuia rosea in the 14-year-old stand. The total stem density increased from 5011 to 9631 individuals per hectare as the age of abandonment increased from 4 to 14 years. The total basal area of individuals _〉 I cm d.b.h, also increased with the age of abandonment. Overall, small individuals （〈 10 cm dbh） contributed to more than half of the total basal area. Species diversity was the highest in the 9-year old stand followed by 14- and 4-year-old stands. We concluded that floristic composition of secondary forests recovers rapidly to the mature forest level compared to structural attributes, which is consistent with the general successional trajectories of tropical dry forest.

关键词： Central America dry forest Neotropics restoration secondary succession abandoned agricultural field Forest recovery

recovery Status and Livestock Use of a Kenyan Montane forest a Decade after Cessation of Human Encroachment

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Open Journal of Ecology 2023年第5期13卷 291-319页

作者： Nereoh C. Leley David K. Langat Abdalla K. Kisiwa Beatah Nzove Elias K. Maranga Wilfred O. Odadi Christine C. Koskey Kenya forestry Research Institute Nairobi Kenya Faculty of Environment and Resources Development Egerton University Njoro Campus Kenya Netherlands Development Organisation (SNV) Nairobi Kenya The Sustainable Trade Initiative (IDH) Kericho Kenya

Montane forest ecosystems support biodiversity and provide varied ecosystem services to adjacent and downstream human communities. However, human-induced disturbances are common in many of these ecosystems, threatening their capacity to sustain their functions. This study assessed the status of woody vegetation and livestock use of a Kenyan montane forest 10 years after government-sanctioned cessation of human encroachment. The findings can inform suitable interventions that support recovery of abandoned forest settlements subjected to continuous anthropogenic disturbances. Selected woody vegetation attributes and livestock disturbance indicators were assessed across three human-driven disturbance regimes (light, moderate and heavy) using stratified-systematic sampling technique. Data on the extent of community dependence on forest grazing were collected from 381 randomly selected forest adjacent households using semi-structured questionnaires. Information on the palatability of plants to livestock was obtained from Focus Group Discussions. Vegetation data were analyzed using linear mixed models, while descriptive analysis was applied on household survey data. A total of 33 woody plant species belonging to 22 families were identified, out of which 55% were perceived to be unpalatable to livestock. Species richness, species diversity, stem density and basal areas declined significantly with increasing levels of disturbance. Specifically, these attributes were 59% - 98% lower in heavily disturbed sites than in moderately and lightly disturbed sites. A vast majority (88%) of the sampled households grazed their livestock in the forest throughout the year. Evidence from this study indicates that intense past and ongoing anthropogenic disturbances caused significant negative effects on the forest vegetation condition, and lowered its capacity to recover. forest managers should prioritize minimizing recurrent anthropogenic disturbances as the forest recovers to ensure successful succession and sustainable provision of e

关键词： Disturbance Forest recovery Livestock Mau forest forest Grazing forest Structure and Composition

Land use legacy for a tropical myco-heterotroph: how spatial patterns of abundance, reproductive effort and success vary

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Journal of Plant Ecology 2019年第2期12卷 367-375页

作者： Stephen McAuliffe James D.Ackerman Raymond L.Tremblay Department of Environmental Science Humboldt State UniversityArcataCAUSA Center for Applied Tropical Ecology and Conservation University of Puerto RicoSan JuanPRUSA Department of Biology University of Puerto Rico17 Ave Universidad Suite 1701San JuanPR 00925-2537USA Department of Biology University of Puerto RicoHumacaoPRUSA

Aims Human land use such as agriculture and logging can have cascad-ing effects on the environment and severely influence forest eco-systems by altering structure,species composition and community processes.These activities may have long-term consequences,which impact Forest recovery.We investigated the legacy of his-torical anthropogenic land use on the current reproductive effort(RE)and success of the understory,myco-heterotrophic orchid,Wullschlaegelia calcarata in Puerto Rico’s tropical rain forest after 80 years of Forest recovery.Methods Our study site was the 16-ha Luquillo forest Dynamics Plot in the Luquillo Experimental forest.We used six 10 m×500 m transect lines that spanned areas with differing levels of historic canopy coverage which are correlated with land use history.We recorded the abundance of W.calcarata plants and measured shoot height,number of flowers,fruit set for all plants and seed set from the most mature,undehisced fruit on a random subset of plants measured.We sought to determine whether or not there is a legacy of land use history on the RE and success of W.calcarata.Of the varying degrees of historic disturbance,we predicted that RE and success would be highest in minimally disturbed old-growth forest,and that soil type differences would be insufficient to affect RE or success.Important Findings We found 1607 plants of W.calcarata,and only one was detected in the most historically disturbed area of the forest.The orchids were most abundant in the two least historically disturbed sites.However,the prevailing trend in all measures of RE is in the opposite direction with greater RE in the forest plots with intermediate levels of histori-cal disturbance.Furthermore,the best model(as a function of AICc and weights)to predict RE is a combination of soil type and cover class.Nevertheless,our measures of reproductive success(fruit and seed set)were best in the least historically disturbed sites and were not associated with soil type.Thus,the best sites for growth are not always the same as

关键词： Forest recovery Orchidaceae tropical forest disturbance ecology Wullschlaegelia

Attributes of stand-age-dependent forest determine technosol fertility of Atlantic forest re-growing on mining tailings in Mariana,Brazil

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Journal of forestry Research 2022年第1期33卷 103-116页

作者： Pedro Manuel Villa Sebastião Venâncio Martins Aline Pilocelli Gabriel Correa Kruschewsky Andreia Aparecida Dias Fabio Haruki Nabeta forest Restoration Laboratory Department of Forest EngineeringUniversidade Federal de ViçosaViçosaMinas GeraisBrazil Fundação Renova Belo HorizonteMinas GeraisBrazil

Understanding how soil fertility changes due to environmental conditions and stand-age-dependent forest attributes is important for local-scale forest restoration.We evaluated the effects of stand-age-dependent forest attributes(plant community composition and litter stock)on soil and technosol fertility across two second-growth Atlantic forests(SGF)after the deposition of mining tailings in Mariana,southeastern Brazil.We hypothesized that technosol fertility in the SGF tailings is positively affected by plant community composition variability,stand age,and litter stock.We used total exchangeable bases and organic matter as fertility indicators for technosol and soil,and species composition and litter stock as stand-age-dependent forest attributes.Our results showed significant differences in the stand-age-dependent forest attributes and soil chemical properties between the two forest patches(SGF tailing and SGF non-tailing)evaluated.Thus,there was a marked gradient of litter storage and fertility between soil and technosol that can be important Forest recovery indicators for the affected plant communities.Furthermore,according to the tested models,we corroborated the hypothesis that technosol fertility is positively affected by stand age,plant community composition variability,and litter stock,which may contribute considerably to Forest recovery on tailings.Our results demonstrate that the fertility predictors analyzed to explain the Forest recovery on tailings can also be considered as ecological indicators for assessing forest restoration in areas impacted by mining tailings in Mariana.

关键词： Ecological indicators Forest recovery Litter stock Nutrient recovery Technosol