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Effects of forest canopy density and epixylic vegetation on nutrient concentrations in decaying logs of a subalpine fir forest

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Forest Ecosystems 2022年第5期9卷 666-673页

作者： Zhuang Wang wanqin yang Bo Tan Qin Wang Lifeng Wang Chenhui Chang Rui Cao Yurui Jiang Jörg Müller School of Life Science Taizhou UniversityTaizhouZhejiang318000China Institute of Ecology and Forestry Sichuan Agricultural UniversityChengdu611130China Field Station Fabrikschleichach Department of Animal Ecology and Tropical Biology(ZoologyⅢ)Julius Maximilians University WürzburgGlashüttenstraße 596181RauhenebrachGermany Bavarian Forest National Park Freyunger Straße 294481GrafenauGermany

Background:Deadwood and the associated epixylic vegetation influence nutrient cycles in forest ecosystems.Open canopies strongly regulate deadwood decomposition and disrupt epixylic vegetation on logs.However,it is unclear how the forest canopy density and epixylic vegetation growth affect the nutrient concentrations in deadwood.Methods:We measured the concentrations of nitrogen(N),phosphorus(P),potassium(K),calcium(Ca),sodium(Na),magnesium(Mg),and manganese(Mn)in experimentally exposed decaying logs placed in gaps,at the edge of gaps,and under the closed canopy during a four-year decomposition experiment in a Subalpine Faxon fir forest(Abies fargesii var.faxoniana)on the eastern Qinghai-Tibetan Plateau,China.To assess the effect of the epixylic vegetation,we experimentally removed it from half of the logs used in the study.Results:Under open canopy conditions in the gap and at the edge,the concentrations for most of the nutrients in the bark and the highly decayed wood were lower than under the closed canopy.The effect of the epixylic treatment on nutrient concentrations for all but K and Na in barks varied with the decay classes.Significantly lower concentrations of N,P,Ca,and Mn following the removal of epixylic vegetation were observed in the wood of decay class IV.Epixylic vegetation significantly increased most nutrient concentrations for decaying barks and wood under open canopy conditions.In contrast,epixylic vegetation had no or minimal effects under the closed canopy.Conclusions:Forest canopy density and epixylic vegetation significantly alter the nutrient concentrations in decaying logs.Open canopies likely accelerate the rate of nutrient cycling between the epixylic vegetation and decaying logs in subalpine forests.

关键词： Coarse woody debris Natural disturbance Forest canopy density Epixylic vegetation Nutrient concentrations

Loss of total phenols from leaf litter of two shrub species: dual responses to alpine forest gap disturbance during winter and the growing season

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Journal of Plant Ecology 2020年第3期13卷 369-377页

作者： Wei He wanqin yang School of Life Science Taizhou UniversityTaizhou 318000ZhejiangChina Long-term Research Station of Alpine Forest Ecosystem Institute of Ecology&ForestrySichuan Agricultural UniversityChengdu 611130SichuanChina College of Horticulture and Forestry Sciences/Hubei Engineering Technology Research Center for Forestry Information Huazhong Agricultural UniversityWuhan 430070HubeiChina

高山森林林窗能够通过调控水热动态进而控制林下生态系统过程。因此,本研究旨在通过两种典型灌木[华西箭竹(Fargeisia nitida(Mitford)Keng f.)和康定柳(Salix paraplesia Schneid.)]凋落叶分解,探索林窗干扰对分解过程中总酚释放的影... 详细信息

高山森林林窗能够通过调控水热动态进而控制林下生态系统过程。因此,本研究旨在通过两种典型灌木[华西箭竹(Fargeisia nitida(Mitford)Keng f.)和康定柳(Salix paraplesia Schneid.)]凋落叶分解,探索林窗干扰对分解过程中总酚释放的影响。我们在一个典型的岷江冷杉林(Abies faxoniana Rehd.)样地,通过设置不同林窗位置(林窗中心南侧、林窗中心北侧、林缘、扩展林缘和林下)进行了凋落物分解实验;并在两年的不同关键时期:雪被形成期、雪被覆盖期、雪被融化期、生长季节初期和生长季节后期,对两种灌木凋落叶分解袋进行采样,并测试其总酚释放率和微生物丰富度(真菌和细菌)。实验结束后,我们发现,雪被厚度、冻融循环以及真菌细菌比对凋落叶的总酚释放具有显著影响。在两年的雪被形成期、雪被覆盖期、雪被融化期和生长季节后期,真菌和细菌丰富度表现出从林窗中心到林下逐渐降低的趋势,而在两年的生长季节初期,其表现出从林窗中心到林下逐渐增加的趋势。而从不同林窗位置来比较,两种灌木凋落叶的总酚释放率仅在第一年各关键时期表现出同真菌细菌丰富度类似的规律。此外,在第一年的冬季,以及从整个第一年和整个两年分解时间段来看,林窗中心位置两种凋落叶的总酚释放率皆较其他林窗位置高。这些研究结果表明,高山森林林窗的形成能够促进凋落叶总酚的释放,尽管其释放对林窗干扰的响应在不同关键时间具有不同的表现。总之,在高寒生物区,林窗的更替消失以及在气候变化背景下冬季变暖导致的雪被覆盖厚度和持续时间的减少会降低凋落叶总酚的释放率。

关键词：高山森林林窗冻融循环真菌与细菌比率积雪深度总酚类化合物

Effects of litter quality and climate change along an elevational gradient on litter decomposition of subalpine forests, Eastern Tibetan Plateau, China

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Journal of Forestry Research 2016年第3期27卷 505-511页

作者： Zhenfeng Xu Jianxiao Zhu Fuzhong Wu yang Liu Bo Tan wanqin yang Key Laboratory of Ecological Forestry Engineering of Sichuan Province Institute of Ecology & Forest Sichuan Agricultural University Chengdu 611130 China Long-term Research Station of Alpine Forest Ecosystems and Monitoring Station for Eco-environments in the Rainy Zone of SW China Chengdu China Department of Ecology College of Environmental SciencesKey Laboratory for Earth Surface of Ministry of EducationPeking University Beijing 10087 China

Temperature and freeze-thaw events are two key factors controlling litter decomposition in cold biomes.Predicted global warming and changes in freeze-thaw cycles therefore may directly or indirectly impact litter decomposition in those ecosystems. Here, we conducted a2-year-long litter decomposition experiment along an elevational gradient from 3000 to 3600 m to determine the potential effects of litter quality, climate warming and freeze-thaw on the mass losses of three litter types [dragon spruce（Picea asperata Mast.）, red birch（Betula albosinensis Burk.）, and minjiang fir（Abies faxoniana Rehd. et Wild）]. Marked differences in mass loss were observed among the litter types and sampling dates. Decay constant（k） values of red birch were significantly higher than those of the needle litters. However, mass losses between elevations did not differ significantly for any litter type.During the winter, lost mass contributed 18.3-28.8 % of the net loss rates of the first year. Statistical analysis showed that the relationships between mass loss and litter chemistry or their ratios varied with decomposition periods. Our results indicated that short-term field incubations could overestimate the k value of litter decomposition.Considerable mass was lost from subalpine forest litters during the wintertime. Potential future warming may not affect the litter decomposition in the subalpine forest ecosystems of eastern Tibetan Plateau.

关键词： Alpine forest Elevational gradient Freeze-thaw Global warming Mass losses

Impacts of soil fauna on nitrogen and phosphorus release during litter decomposition were differently controlled by plant species and ecosystem type

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Journal of Forestry Research 2019年第3期30卷 921-930页

作者： Yan Peng wanqin yang Kai Yue Bo Tan Fuzhong Wu Long-term Research Station of Alpine Forest Ecosystems Provincial Key Laboratory of Ecological Forestry EngineeringInstitute of Ecology and ForestrySichuan Agricultural UniversityChengdu 611130SichuanPeople’s Republic of China Department of Geosciences and Natural Resource Management University of CopenhagenRolighedsvej 231958 Frederiksberg CDenmark Collaborative Innovation Center for Ecological Security in the Upper Reaches of the yangtze River Chengdu 611130 People’s Republic of China

The dynamics of litter nitrogen (N) and phosphorus (P) release could be affected by soil fauna and environmental conditions. The objective of the present study was to investigate the effects of soil fauna on the dynamics of N and P during foliar litter decomposition in three types of ecosystems (i.e., montane forest, ecotone, and dry valley) along an elevation gradient. A field experiment using litterbags with two different mesh sizes (0.04 and 3 mm) was conducted from November 2013 to October 2014. Nitrogen and P release rates in decomposing foliar litter from fir (Abies faxoniana) and birch (Betula albosinensis) in montane forest, oak (Quercus baronii) and cypress (Cupressus chengiana) in ecotone, and cypress and clovershrub (Campylotropis macrocarpa) in dry valley were investigated in the upper reaches of the yangtze River. Soil fauna strongly affected N and P release across different decomposition periods and ecosystem types. The average release rate of N mediated by soil fauna across the entire year was higher in the dry valley (15.6–37.3%) than in the montane forest (0.5–6.4%) and the ecotone (- 3.7–4.9%). The effects of soil fauna on P release rate were manifest in both the montane forest and the dry valley. Moreover, the impacts of soil fauna can vary substantially among different decomposition periods. Our results indicated that soil fauna can significantly affect N and P release during litter decomposition. The N release rate mediated by fauna was likely to be more sensitive to the effects of plant species (i.e., initial litter chemical traits), while the P release rate mediated by soil fauna might be subject to the effects of local-scale environmental factors (e.g., temperature) to a greater extent.

关键词： Dry valley Ecotone Environmental factors Litterbag Montane forest Release rate

Cumulative cellulolytic enzyme activities and initial litter quality in prediction of cellulose degradation in an alpine meadow of the eastern Tibetan Plateau

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Journal of Plant Ecology 2020年第1期13卷 51-58页

作者： Yamei Chen yang Liu Jian Zhang wanqin yang Changchun Deng Runlian He Key Laboratory of Ecological Forestry Engineering Long-Term Research Station of Alpine Forest EcosystemsInstitute of Ecology&ForestrySichuan Agricultural University211 Huimin RoadWenjiang DistrictChengdu 611130China

植物凋落物分解是决定陆地生态系统碳和养分循环的关键生态系统过程。作为凋落物的主要组成部分,纤维素是与凋落物分解相关的微生物的重要能量来源。纤维素酶在凋落物纤维素降解过程中的重要作用已为人们所熟知,然而纤维素降解的季节模... 详细信息

植物凋落物分解是决定陆地生态系统碳和养分循环的关键生态系统过程。作为凋落物的主要组成部分,纤维素是与凋落物分解相关的微生物的重要能量来源。纤维素酶在凋落物纤维素降解过程中的重要作用已为人们所熟知,然而纤维素降解的季节模式、累积酶活性和凋落物质量是否能预测高寒草甸的纤维素降解仍是一个未解之谜,这限制了我们对草本植物凋落物纤维素降解的认识。为了探究纤维素降解的季节性模式以及累积纤维素分解酶活性和凋落叶初始质量对纤维素降解的影响,我们在青藏高原东部的高山草甸选取了三种优势种[圆叶筋骨草(Ajuga ovalifolia)、藏羊茅(Festuca wallichanica)和草甸马先蒿(Pedicularis roylei)],进行了为期两年的凋落物网袋分解实验。我们的研究发现,纤维素在第一年中迅速降解且降解率超过50%,而且主要发生在第一个生长季(31.9%-43.3%)在两年的分解过程中,纤维素降解由累积内切葡聚糖酶(R^(2)=0.70),累积纤维二糖水解酶(R^(2)=0.59)和累积1,4-β-葡糖苷酶(R^(2)=0.57)共同驱动。此外,在这两年的分解过程中,纤维素、可溶性有机碳、总酚、木质素的浓度和木质素/N可以解释纤维素降解变异的(52%-78%)。用初始纤维素浓度模型预测纤维素降解效果最佳(R^(2)=0.78)。在凋落物的分解过程中,酶效率和微生物对纤维素分解酶的分配因物种而异。藏羊茅凋落物中纤维素酶效率较高,但质量相对较低。与草甸马先蒿相比,完全降解圆叶筋骨草和藏羊茅的纤维素需要4倍和6.7倍的内切葡聚糖酶、3倍和4.5倍的纤维二糖水解酶、1.2倍和1.4倍的1,4-β-葡糖苷酶。我们的研究结果表明,虽然微生物酶活性和凋落物初始质量都对高山草甸纤维素降解有显著影响,但使用纤维素浓度来预测纤维素降解是简化凋落物分解过程中纤维素降解和C循环模型的好方法。

关键词：累积纤维素酶纤维素降解酶效率初始凋落物质量

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

Nitrous oxide emissions from three temperate forest types in the Qinling Mountains,China

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Journal of Forestry Research 2019年第4期30卷 1417-1427页

作者： Wei Xue Changhui Peng Huai Chen Hui Wang Qiuan Zhu Yanzheng yang Junjun Zhang wanqin yang Institute of Ecology and Forestry Sichuan Agricultural UniversityChengdu 611130People's Republic of China Laboratory for Ecological Forecasting and Global Change College of ForestryNorthwest A&F UniversityYangling 712100People's Republic of China Department of Biology Sciences Institute of Environment SciencesUniversity of Quebec at MontrealCase Postale 888&Succursale Centre-VilleMontreal H3C 3P&Canada Chengdu Institute of Biology Chinese Academy of SciencesChengdu 610041People's Republic of China

To understand soil N2O fluxes from temperate forests in a climate-sensitive transitional zone,N2O emissions from three temperate forest types(Pinus tabulaeformis,PTT;Pinus armandii,PAT;and Quercus aliena var.acuteserrata,QAT)were monitored using the static closed-chamber method from June 2013 to May 2015 in the Huoditang Forest region of the Qinling Mountains,China.The results showed that these three forest types acted as N2O sources,releasing a mean combined level of 1.35±0.56 kg N2O ha^-1 a^-1,ranging from0.98±0.37 kg N2O ha^-1 a^-1 in PAT to 1.67±0.41 kg N2O ha^-1 a^-1 in QAT.N2O emission fluctuated seasonally,with highest levels during the summer for all three forest types.N2O flux had a significantly positive correlation with soil temperature at a depth of 5 cm or in the water-filled pore space,where the correlation was stronger for temperature than for the water-filled pore space.N2O flux was positively correlated with available soil nitrogen in QAT and PAT.Our results indicate that N2O flux is mainly controlled by soil temperature in the temperate forest in the Qinling Mountains.

关键词： Forest types Greenhouse gases N2O fluxes Qinling Mountains Soil temperature

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济阳坳陷深层地热资源研究进展与下步展望

油气地质与采收率 2024年第4期31卷 196-206页

作者：杨永红杨万芹陈云华崔营滨中国石化胜利油田分公司勘探开发研究院山东东营257015

济阳坳陷地热资源分布范围广、资源潜力大,是胜利油区未来地热资源开发利用的重要方向。为科学、高效地开发利用济阳坳陷地热资源,系统梳理了关于济阳坳陷水热型和干热岩型地热资源的热储层、热盖层、热源等地热地质条件,分别计算了2类... 详细信息

济阳坳陷地热资源分布范围广、资源潜力大,是胜利油区未来地热资源开发利用的重要方向。为科学、高效地开发利用济阳坳陷地热资源,系统梳理了关于济阳坳陷水热型和干热岩型地热资源的热储层、热盖层、热源等地热地质条件,分别计算了2类地热资源的资源量,揭示其地热资源潜力。研究结果表明,济阳坳陷水热型地热资源主要赋存在馆陶组、东营组及下古生界等,其中馆陶组为水热型地热资源潜力最大的层系,分布广、资源量大,是下步重点勘探开发利用层系。济阳坳陷属于“冷壳热幔型”沉积盆地,具有较高的大地热流值,干热岩型地热资源热储层主要为太古宇的岩浆岩和变质岩,深部地幔热流是其主要热源,热储层分布面积大,温度均较高,其资源丰度为渤海湾盆地中最高。济阳坳陷地热资源丰富,为加快其开发利用步伐,建议水热型地热资源要加强地热资源与油气的关系及资源分区评价2项关键工作;干热岩型地热资源的勘探开发仍处于起步探索阶段,今后需要重点加强其热储层类型的选择与热源机制2个方面的研究。

关键词：地热资源干热岩热储层热源地温场济阳坳陷

Changes in plant debris and carbon stocks across a subalpine forest successional series

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Forest Ecosystems 2021年第3期8卷 523-536页

作者： Zhihui Wang Lianjun Zhao Yi Bai Fei Li Jianfeng Hou Xuqing Li Yurui Jiang Yuyue Deng Bingqian Zheng wanqin yang School of Life Sciences Taizhou UniversityTaizhou 318000China Wanglang National Nature Reserve Authority Pingwu 622550SichuanChina

Background:As a structurally and functionally important component in forest ecosystems,plant debris plays a crucial role in the global carbon cycle.Although it is well known that plant debris stocks vary greatly with tree species composition,forest type,forest origin,and stand age,simultaneous investigation on the changes in woody and non-woody debris biomass and their carbon stock with forest succession has not been reported.Therefore,woody and non-woody debris and carbon stocks were investigated across a subalpine forest successional gradient in Wanglang National Nature Reserve on the eastern Qinghai-Tibet Plateau.Results:Plant debris ranged from 25.19 to 82.89 Mg∙ha−1 and showed a global increasing tendency across the subalpine forest successional series except for decreasing at the S4 successional stage.Accordingly,the ratios of woody to non-woody debris stocks ranged from 26.58 to 208.89,and the highest and lowest ratios of woody to non-woody debris stocks were respectively observed in mid-successional coniferous forest and shrub forest,implying that woody debris dominates the plant debris.In particular,the ratios of coarse to fine woody debris stocks varied greatly with the successional stage,and the highest and lowest ratios were found in later and earlier successional subalpine forests,respectively.Furthermore,the woody debris stock varied greatly with diameter size,and larger diameter woody debris dominated the plant debris.Correspondingly,the carbon stock of plant debris ranged from 10.30 to 38.87 Mg∙ha−1 across the successional series,and the highest and lowest values were observed in the mid-coniferous stage and shrub forest stage,respectively.Most importantly,the carbon stored in coarse woody debris in later successional forests was four times higher than in earlier successional forests.Conclusions:The stock and role of woody debris,particularly coarse woody debris,varied greatly with the forest successional stage and dominated the carbon cycle in the subalpine forest ecosystem.Thus,preserving coarse

关键词： Coarse woody debris Fine woody debris Forest successional series Later successional stage Earlier successional stage Log decay class Diameter size