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Effects of Seasonal Freeze-Thaw Cycles on Quantity of Soil Microbes in subalpine Fir Forest

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Chinese Forestry Science and Technology 2012年第3期11卷 37-37页

作者： Wang Huaiyu Yang Wanqin Mianyang Normal University Institute of Ecological Forestry Sichuan Agricultural University

Fir(Abies faxoniana) distributes widely in the alpine and subalpine region of western *** understand effects of freeze-thaw events on soil microbial community,microbial number was investigated monthly in a fir forest,employing the method of lab freeze/thaw cycles in combination with field soil *** and actinomycete number in soil decreased and fungal count increased after a seasonal freeze-thaw season *** and fungal counts increased with the decreased altitude,while actinomycete count decreased with the decreased *** microbes had various change patterns with altitude in humus layer(AL), illuvial layer(BL) and parent material layer(CL). Compared with the 3 582 m altitude,bacterial count in the AL and CL at the 3 298 m altitude increased 4.2%and 7.0%,respectively,but that in the BL decreased 0.6%.Meanwhile,bacterial count increased 11.5%,3.5%and 2.1%in the AL,BL and CL at the 3 023 m altitude in comparison with the 3 298 m altitude,*** count in the AL,BL and CL increased by 10.5%,10.3%and 16.4%at the 3 298 m altitude in comparison with 3 582 m altitude,respectively,while it increased by 2.4%,1.7%and 3.5%at the 3 023 m altitude in comparison with 3 298 m altitude,respectively. Actinomycete count in the AL at the 3 298 m altitude increased by 0.7%than that at the 3 582 m altitude, but decreased 5.9%and 13.9%in the BL and *** the AL and BL,it increased 5.2%and 5.2% respectively at the 3 023 m altitude than that at the 3 298 m altitude,while in the CL it decreased 12.4%.These results were in agreement with the simulation freeze/thaw cycle experiment in *** results also revealed that the seasonal freeze-thaw cycle increased the ratio of soil fungi to bacteria. These results demonstrated that different microbial groups responded differentially to the seasonal freeze-thaw cycle,which may be an important ecological mechanism for maintaining the seasonal frozen ecosystem.

关键词： seasonal freeze-thaw subalpine fir forest soil microbe

Altitudinal variations of hydraulic traits in Faxon fir(Abies fargesii ***):Mechanistic controls and environmental adaptability

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Forest Ecosystems 2022年第3期9卷 427-438页

作者： Shao-an Pan Guangyou Hao Xuhua Li Qiuhong Feng Xingliang Liu Osbert J.Sun School of Ecology and Nature Conservation Beijing Forestry UniversityBeijing100083China Institute of Forestry and Climate Change Research Beijing Forestry UniversityBeijing100083China Institute of Applied Ecology Chinese Academy of SciencesShenyang110016China Sichuan Provincial Key Laboratory of Ecological Restoration and Conservation for Forest and Wetland Sichuan Academy of Forestry SciencesChengdu610081China Sichuan Wolong Forest Ecosystem Research Station Wenchuan623006China

Global climate change has been seen to result in marked impacts on forest ecosystems such as accelerated tree mortality worldwide due to incidental hydraulic failure caused by intensified and more frequent occurrence of extreme drought and ***,it is well understood how the tree hydrological strategies would adjust to environmental variability brough about by climate *** we investigated the hydraulic adjustment as a mechanism of acclimation to different climate conditions along an altitudinal gradient in Faxon fir(Abies fargesii ***)–a tree species that plays a key role in conservation of wildlife and maintenance of ecosystem services in subalpine *** hydraulic traits and selective morphological and physiological variables were measured seasonally along an altitudinal gradient from 2,800 to 3,600 m *** found that the native percentage loss of conductivity(PLC)increased with altitude across the seasonal *** the native sapwood-specific hydraulic conductivity(Ks)and native leaf-specific hydraulic conductivity(Kl)significantly decreased with altitude for measurements in July and October,coinciding with the timing for peak growth and pre-dormancy,*** morphological traits varied toward more conservative tree hydrological strategies with increases in altitude,exhibiting trade-offs with hydraulic *** total non-structural carbohydrates in both needle(NSCNeedle)and branch(NSCBranch)as well as photosynthetic capacity of current-year leaves played variable roles in maintaining the integrity of the hydraulic functioning and shaping the hydraulic adjustment under prevailing environmental *** findings indicate that Faxon fir possesses some degree of hydraulic adaptability to water limitation imposed by climate fluctuations in subalpine region through morphological and physiological modifications.

关键词： Climate change Eco-safety Environmental vulnerability Faxon fir Hydraulic risk Habitat constraints Water stress subalpine

Effects of stand types on recreational preferences of society in the Sub-Alpine Zone,northern Turkey

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Journal of Mountain Science 2022年第11期19卷 3246-3256页

作者： Tuğrul VAROL Halil BarışÖZEL Ferhat KARA İlkimÇAVUŞKARA Sezgin AYAN Bartın University Faculty of ForestryDepartment of Forest EngineeringBartın 74100Turkey Kastamonu University Faculty of ForestryDepartment of Forest EngineeringKastamonu 37150Turkey Kastamonu-Ilgaz Mountain National Park Directorate Kastamonu 37100Turkey

The main objective of this study was to examine how different stand types influenced the tendency of visitors for varying recreational activities(i.e.,hiking,trekking,camping and hunting)from 1993 to 2018 in the surrounding areas of Uluyayla Natural Recreation Site in Bart1n,northern Turkey.A total of 627 visitors were selected on a voluntary basis,and questioned in the form of *** of the participants were in the age of 21-40 years old,and they were mostly(62.4%)*** of the participants(82.7%)lived in cities,while 62.8%of them were tourists when visiting the *** determining the preferences of the visitors regarding the stand types for different recreational activities,several images of each stand were shared with them,and they were asked which stand type they would prefer for a given recreation activity(i.e.,hiking,tracking,camping and hunting).A range of options from 1 to 5 in Likert's scale was used in evaluating the given *** degree of positive and negative effects was examined via trend *** was found that stand type had influence on the preferences of visitors regarding the recreational *** general,unmanaged and moderately treated stands were more preferred by visitors for the recreational purposes,compared to the previously managed *** the other hand,visitors'preference for the activities were different during two periods(i.e.,1993-2005 and 2006-2018).For each recreational activity,there was an increasing trend from 1993 to *** had been a continuous increase for hunting since 1996,and for trekking and camping after *** increases between 1993-1996 and 1996-1999 were likely due to the increasing awareness of the society as a result of the training and consciousness raising activities for nature *** demand on the recreational activities continuously increased in unmanaged and moderately treated stands,while no significant changes were examined in the previously managed *** st

关键词： Camping Hunting National Park Recreation subalpine Silviculture

Variations in root chemistry of three common forest species,southwestern China

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Journal of Forestry Research 2019年第3期30卷 827-834页

作者： Qun Liu Wanqin Yang Fuzhong Wu Bo Tan Li Zhang Zhenfeng Xu Long-term Research Station of Alpine Forest Ecosystems Institute of Forest and Ecology Sichuan Agricultural University

Root chemistry varies with tree species and root diameter but little information is available about Tibetan forest species. The root chemistry of three root diameter classes (fine: 0–2 mm, medium: 2–5 mm, coarse: 5–10 mm) of three subalpine species (Abies faxoniana Rehd. and Wild, Picea asperata Mast., and Betula albosinensis Burkill) were investigated. Carbon concentrations, and carbon/nitrogen and carbon/phosphorus ratios increased but nitrogen, phosphorus and nitrogen/phosphorus ratios decreased with increasing root diameter. The roots of the conifers had higher carbon levels, and higher carbon/nitrogen and carbon/phosphorus ratios than birch roots. The opposite was found with nitrogen and phosphorus levels and nitrogen/phosphorus ratios. Lignin concentrations decreased but cellulose concentrations increased with greater root diameters. The results indicate that diameter-associated variations in root chemistry may regulate their contribution to detrital pools which has important implications for below-ground carbon and nutrient cycles in these subalpine forests.

关键词： Root diameter Lignin Cellulose Stoichiometry subalpine forest

Elevational patterns of carbon,nitrogen and phosphorus in understory bryophytes on the eastern slope of Gongga Mountain,China

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Journal of Plant Ecology 2019年第4期12卷 781-786页

作者： Zhe Wang Chunyan Pi Xiaoming Li Weikai Bao College of Life Sciences Shanghai Normal UniversityShanghai 200234China CAS Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization&Ecological Restoration and Biodiversity Conservation Key Laboratory of Sichuan Province Chengdu Institute of BiologyChinese Academy of SciencesChengdu 610041China

Aims The nutrient uptake,requirement and releasing rates of bryophytes are very different from those of ***,it is diffi-cult to make a quantitative evaluation of bryophytes’roles in nu-trient cycling and their specific eco-physiological adaptations due to lack of knowledge of their concentrations and stoichiometric ratios of carbon(C),nitrogen(N)and phosphorus(P).To fill this gap,the present study aims to investigate:(i)what are the elevational trends of C,N and P concentrations and stoichiometric ratios of bryophytes?(ii)whether C,N and P concentrations and stoichio-metric ratios of bryophytes differ between different bryophyte types(in terms of the growth form and living substrate)?and(iii)how do the exponent scalings of N and P of bryophytes change along the elevational gradient?Methods We measured and calculated the C,N,P concentrations and stoi-chiometric ratios of bryophytes from four elevations on the eastern slope of Gongga Mountain(22 species in total).Differences in these traits among elevations,and between different bryophyte types were *** log-log allometric regression parameters of N and P at each elevation were also determined and *** Findings The C,N and P concentrations of bryophytes showed decreasing trends with increasing *** specifically,erect bryo-phytes possessed higher C and N concentrations than those of pros-trate species,and terricolous species had higher P concentration than that of corticolous and saxicolous *** from different elevations had an invariant allometric regression slope for P versus *** research at a larger scale is in need for a more generalized law of bryophytes.

关键词： allometric scaling growth form living substrate stoichiometric ratio subalpine

How forest gaps shaped plant diversity along an elevational gradient in Wolong National Nature Reserve?

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Journal of Geographical Sciences 2019年第7期29卷 1081-1097页

作者： CHEN Li HAN Wangya LIU Dan LIU Guohua State Key Laboratory of Urban and Regional Ecology Research Center for Eco-environmental Sciences CAS Beijing 100085 China School of Resources and Environment University of Chinese Academy of Sciences Beijing 100049 China

Understanding the underlying ecological processes that control plant diversity within(α-diversity) and among(β-diversity) forest gaps is important for managing natural forest ecosystems, and it is also a prerequisite for identifying the formation and maintenance mechanisms of forest plant communities. In this study, we focused on the interrelationships among habitat type(gap/non-gap plots), gap size, elevation and environmental factors, and we explored their effects on plant diversity(α-diversity and β-diversity). To do this, a total of 21 non-gap(i.e., closed canopy) plots(100 m2) and 63 gap plots, including 21 with large gaps(200–410 m2), 21 with medium gaps(100–200 m2) and 21 with small gaps(38.5– 100 m2),were selected along an elevational gradient in a subalpine coniferous forest of southwestern China. Using structural equation models(SEMs), we analyzed how forest gaps affected plant diversity(α-diversity and β-diversity) along an elevational gradient. The results showed that(1) as elevation increased, unimodal patterns of α-diversity were found in different-sized gaps, and β-diversity showed a consistent sinusoidal function pattern in different-sized gaps. The gap size was positively related to α-diversity, but this effect disappeared above 3500 masl. Moreover, the patterns of α-diversity and β-diversity in non-gap plots were irregular along the elevational gradient.(2) SEMs demonstrated that many environmental factors, such as the annual mean air temperature(AMAT), ultraviolet-A radiation(365 nm, UV-A365), ultraviolet-B1 radiation(297 nm, UV-B297), moss thickness(MT), soil carbon/nitrogen ratio(C/N ratio), NH4-N and NO3-N, were significantly affected by elevation, which then affected α-diversity and β-diversity. The photosynthetic photon flux density(PPFD), UV-A365 and UV-B297 were significantly higher in plots with forest gaps than in the non-gap plots. Moreover, the PPFD and UV-A365 were positively and directly affected by gap size. Surprisingly, except for

关键词： forest gap elevation environmental factors plant diversity subalpine coniferous forest