Soil water use strategy of dominant species in typical natural and planted shrubs in loess hilly Region北大核心CSCD

Aims Artemisia gmelinii is a dominant specie naturally established after abandonment of cultivated lands in the Loess Plateau, and Caragana korshinskii is one of the main planted shrub species to control soil erosion. Improved understanding of water use strategies of these two species is of great significance to evaluate the sustainable development of the Loess Plateau under the trend of climate warming and increasing drought events. Methods Stable oxygen-18 isotope was used to determine seasonal variations in the water sources of native A. gmelinii communities established after abandonment of cultivated lands for 7 and 30 years and planted C. korshinskii after 30 years. The contributions of soil water from different depths to water uptake were estimated by the MixSIR Bayesian mixing model. The geometric mean regression method was used to fit the line of precipitation to get the local meteoric water line (LWML). Important findings The stable hydrogen isotope rate (δD) and stable oxygen isotope rate (δ18O) of soil water and xylem water plotted to the right side of the LWML, indicating that the isotopic compositions of soil water were enriched due to evaporation. The native A. gmelinii communities established after abandonment of cultivated lands for 7 years and planted C. korshinskii after 30 years showed plasticity in switching water sources from different soil layers, extracting water from shallow soil (0-40 cm) when soil water was available, but deeper soil (40-80 cm) when shallow soil water was dry. In contrast, A. gmelinii growing in site after cultivation abandonment for 30 years mainly relied on water from the surface soil (0-10 cm) throughout the growing season. Our results suggest that the ability of A. gmelinii to compete for soil water reduces with aging of the community while the planted C. korshinskii will have competitive advantage under the condition of increasing frequency of drought events in the future.     

Community Characteristics of Early Recovery Vegetation on Abandoned Lands of Shifting Cultivation in Bawangling of Hainan Island, South China

Shifting cultivation is a major form of agricultural practice in most parts of tropical regions worldwide. In places where the bush fallow period is excessively shortened or the period of cultivation is extended for too long, the rate of vegetation recovery and biodiversity on abandoned lands of shifting cultivation would decline. The recovery of the secondary plant communities could even be inhibited for a prolonged period because of grass occupancy. Because of the vital significance of the early recovery communities to secondary succession, we studied the community characteristics of early recovery vegetation on abandoned lands of shifting cultivation in Bawangling of Hainan Island. Measurements were made of the community composition and structure of early recovery vegetation. The sprouting abilities of different functional groups and different species in the same functional group, and the effect of the grass functional group on the composition and quantitative characteristics of tree and shrub functional groups were analyzed. Results indicated that only a few families, genera, or species apparently dominated in the early recovery vegetation on the abandoned lands of shifting cultivation and that deciduous species occurred with a rather high percentage in this early recovery community compared with the natural secondary or old growth forests. Smallsized individuals dominated the woody community. The abundance and basal area of sprouting stems for species in the tree functional group were greater than those of seeder stems, whereas the abundance and basal area of resprouters and seeders for species in the shrub functional group did not differ. The total abundance of stems for the community, stem abundances for species in tree or shrub functional groups, and for seeder or resprouter stems were all negatively correlated with coverage of the grass functional group. The mean sprouting ability in the tree functional group was greater than in the shrub functional group. The sprouting ability for different species in the same functional group was also significantly different.     

Different Patterns of Changes in the Dry Season Diameter at Breast Height of Dominant and Evergreen Tree Species in a Mature Subtropical Forest in South China

Information on changes in diameter at breast height （DBH） is important for net primary production （NPP） estimates, timing of forest inventory, and forest management. In the present study, patterns of DBH change were measured under field conditions during the dry season for three dominant and native tree species in a monsoon evergreen broad-leaved forest in the Dinghushan Biosphere Reserve. For each tree species, different patterns of DBH change were observed. In the case of the fast-growing tree species Castanopsis chinensis Hance, large diurnal fluctuations occur, with a peak DBH in the early morning （around 05：00 h） that decreases to a minimum by about 14：00 h. Both Schima superba Gardn. et Chemp and Cryptocarya chinensis （Hance） Hemsh exhibited less diurnal swelling and shrinkage. Diurnal fluctuations for these species were observed on a few occasions over the period of observation. Graphical comparisons and statistical analysis of changes in DBH with meteorological variables indicate that for different trees, the different changes in DBH observed responded to different meteorological variables. Large stem changes were found to occur for Ca. chinensis trees that were associated with variations in solar radiation. However, both S. superba and Cr. chinensis were found to be less sensitive to solar radiation. Changes in the DBH of these two species were found to be controlled mainly by soil temperature and soil moisture. During the later dry season, with a lower soil temperature and soil moisture, all three tree species stopped growing and only negligible shrinkage, expansion, or fluctuation occurred, suggesting that the optimum time to measure tree growth in the Dinghushan Biosphere Reserve is the later dry season.     

The legacy effects of rubber defoliation period on the refoliation phenology,leaf disease,and latex yieldOA

The leaf phenology of trees has received particular attention for its crucial role in the global water and carbon balances,ecosystem,and species distribution.However,current studies on leaf phenology have mainly focused on temperate trees,while few studies including tropical trees.Little attention has been paid to globally extensive industrial plantations.Rubber plantations are important to both the local and global economies.In this study,we investigated the legacy effects of defoliation phenol...     

Water sources of dominant species in three alpine ecosystems on the Tibetan Plateau, China

Plant water sources were estimated by two or three compartment linear mixing models using hydrogen and oxygen isotope （δD and δ^18O） values of different components such as plant xylem water, precipitation and river water as well as soil water on the Tibetan Plateau in the summer of 2005. Four dominant species （Quercus aquifolioides, Pinus tabulaeformis, Salix rehderiana and Nitraria tangutorum） in three typical ecosystems （forest, shrub and desert） were investigated in this study. Stable isotope ratios of the summer precipitations and the soil water presented variations in spatial and temporal scales. δ^18O values of N. tangutorum xylem water were constant in the whole growth season and very similar to those of deep soil water. Water sources for all of the plants came from both precipitations and soil water. Plants switched rapidly among different water sources when environmental water conditions changed. Rainwater had different contributions to the plants, which was influenced by amounts of precipitation. The percentage of plant xylem water derived from rainwater rose with an increase in precipitation. Water sources for broad-leaved and coniferous species were different although they grew in the same environmental conditions. For example, the broad-leaved species Q. aquifolioides used mainly the water from deep soil, while 92.5% of xylem water of the coniferous species P. tabulaeformis was derived from rainwater during the growth season. The study will be helpful for us to fully understand responses of species on the Tibetan Plateau to changes in precipitation patterns, and to assess accurately changes of vegetation distribution in the future.     

Seasonal changes on two different spatial scales： response of aquatic invertebrates to water body and microhabitat

Knowledge about the spatial and temporal scales of both habitat use and the functional significance of different adaptations is essential for an understanding of the population dynamics of invertebrate assemblages. This fundamental knowledge is not only interesting from an academic point of view, but is sorely lacking and needed in the field of restoration ecology. Many species are threatened due to degradation. Knowing what environmental conditions are needed dtLring the life cycle of these species is important in the design of restoration measures which aim to lift existing bottlenecks for threatened species. To assess the relative importance of water type and microhabitat in structuring the invertebrate assemblage during different seasons, invertebrates were sampled in three water bodies differing in trophic level and acidity. Different parts within a water body （microhabitats） were sampled separately and each water body was sampled in all four seasons. Results show that water body is an important factor structuring the invertebrate assemblage early in the season, whereas microhabitat became more important later in the season. Structural complexity of microhabitats was related to the type of locomotion employed by invertebrates. Seasonal differences could be related to population dynamics （reproduction, mortality）. Moreover, fluctuations in resource availability were expected to differ between the water bodies, with highest fluctuations in the eutrophic water body and with fluctuations becoming less predictable later in the season. This was confirmed by the data： species synchronization to pulses in food availability was strongest in the eutrophic water body. Moreover, synchronization was strongest in summer, while in autumn waters were invaded by dispersive species. Based on these results a synthesis is presented on the functioning of the different waters during the different seasons.     

Variations and interrelationships of foliar hydraulic and photosynthetic traits for Larix gmelinii北大核心CSCD

Aims: Variations and potential trade-offs of leaf hydraulic and photosynthetic traits are essential for assessing and predicting the effect of climate change on tree survival, growth and distribution. Our aims were to examine variations and interrelationships of leaf hydraulic and photosynthetic traits in response to changes in site conditions for Dahurian larch (Larix gmelinii)-a dominant tree species in Chinese boreal forests. Methods: This study was conducted at the Maoershan Forest Ecosystem Research Station. A transect of 27 year-old Dahurian larch plantation was established that consisted of five plots extending from the valley to the ridge of a slope. The predawn leaf water potential (ψpre), area- and mass-based leaf hydraulic conductance (Karea and Kmass, respectively), resistance to embolism capacity (P50), leaf mass per area (LMA), net photosynthetic rate (A), and leaf nitrogen content (N) were measured in August 2016. Important findings: The ψpre, Karea, Kmass, P50, A, LMA, and N all varied significantly among the plots (p < 0.05), indicating significant intra-specific variations in these traits in response to the changes in site conditions. The P50 was significantly (p < 0.05) correlated with ψpre, Karea or Kmass, suggesting that a trade-off between hydraulic efficiency and safety exist within the species to some degree. There were significant (p < 0.05) pairwise correlations between A, LMA, and N. Nevertheless, there was no significant (p < 0.05) correlation between the measured photosynthetic traits and hydraulic traits. We concluded that the intra-specific variations and multiple interrelationships of the leaf hydraulic and photosynthetic traits for the larch reflect the plasticity of its leaf traits and strategies of its survival and growth as a result of its acclimation to diverse site conditions.     

Bugs beneath the surface： the functional significance of soil macroinvertebrates to landscape health in Australia＇s tropical savannas

Soil macroinvertebrates play an important role in sustaining production and biodiversity in Australia＇ s tropical savannas. For example, termites, through their foraging and nesting activities, recycle nutrients and carbon and produce soil pores that facilitate water infiltration. The challenge ahead is to quantitatively understand the relationships and processes that drive this. What roles do different species and functional groups of macroinvertebrates play in various landscape processes？ What are the effects of different land management practices （e.g., domestic cattle grazing, fire） on these relationships, and the consequences for landscape health？ This paper presents preliminary results from studies in northern Australia, that examine the effects of land condition and domestic cattle grazing on soil macroinvertebrates, and the potential for termites to be used as a tool to restore soil function in degraded areas. In northern Australia, increased degradation seems to be associated with declines in the diversity and activity of macroinvertebrates. Termites appear to be one of the most resilient groups, with some species capable of maintaining activity in degraded landscapes.     

What is the optimal number of leaves when measuring leaf area of tree species in a forest community?北大核心CSCD

Aims Leaf size, as one of the easier measured plant morphological traits, reflects response and adaptation of plants to environment and indicates functions and processes of ecosystem. When measuring leaf size (the leaf area, LA) on the field, the common accepted practice considers that the number of leaves picked off is often 10–20. However, what is the optimal number of leaves remains unknown. In this study, we attempt to determine how many leaves should be investigated when the leaf size of a tree is measured. Methods This study selected two dominant tree species (Schima superba, Ss and Liquidambar formosana, Lf) from a broadleaved evergreen and deciduous mixed forest in Jinhua Mountain of Zhejiang Province, eastern China. On the basis of sampling (>2 500 leaves for each tree) in five classes of the diameter of breast height (DBH) of tree species and at six directions for each individual, variations of LA in the two tree species are statistically analyzed. The optimal number of leaves, which can mostly represent the common leaf size feature, is further investigated. Important findings Mean LA of the evergreen tree Ss was smaller than that of the deciduous tree Lf. The former was (41.60 10.88) cm2 (16.74–100.80 cm2) and the latter was (57.65 19.35) cm2 (11.31–129.51 cm2). LA of Lf was significantly related to the DBH, but LA of Ss was not. LA of both trees in the middle DBH class (15–20 cm) was not significantly different from their means. LA of two trees have no significant correlations with the sampling directions, but LA at the east, west and bottom had no significant relationships with their means. Considering the representativeness and practicality in the field sampling, the priority of selecting leaves can target the bottom direction of middle diameter mature trees. Random sampling analysis indicated that, the optimal number of leaves for tree LA measurement is species specific. The optimal number of leaves for Ss is 40 and for Lf is at least 170, respectively. Therefore, when measuring leaf area in a forest community, the optimal sampling number of leaves should not be limited to 10–20 leaves. Under sufficient labor, material and time, more leaves should be measured. © Chinese Journal of Plant Ecology.     

Planting position and shade enhance native seedling performance in forest restoration for an endangered malagasy plant

The critically endangered tree Schizolaena tampoketsana is confined to a few diminished and degraded forest fragments on the Malagasy highlands. This habitat is vulnerable to loss due to frequent fires in the surrounding grassland that threaten to spread into the forest. One of these fragments is the focus a conservation project and here the managers aim to conserve S. tampoketsana by restoring its forest habitat to its former extent as evidenced by remnant woody plants. To inform this activity the survival and early-stage growth of seedlings of four locally native tree species were compared under contrasting conditions of proximity to the remaining forest and shade. After 12 months, seedlings of three species(Baronia taratana, Eugenia pluricymosa, Uapaca densifolia) survived better and experienced improved growth in height in grassland close to the existing forest rather than distant from it, and two survived better with shade rather than unshaded. A number of mechanisms could explain these results including reduced exposure to desiccating sunlight and winds and better soil and greater water availability close to the forest. The seedlings of one species(Nuxia capitata) survived well under all conditions. This study suggests that reforestation in these dry highlands is most feasible adjacent to remnant forest fragments and in microhabitats that minimize water loss, though young plants of some tree species may be capable of surviving in harsher conditions.     

Water sources of Populus euphratica and Tamarix ramosissima in Ejina Delta,the lower reaches of the Heihe River China北大核心CSCD

Aims: We aim to evaluate the water sources of typical riparian arbor species (Populus euphratica) and shrub species (Tamarix ramosissima), and analyze the spatial and temporal dynamics of plant water source in Ejina Delta, the lower reaches of the Heihe River. China. Methods: Eight sampling sites were selected in the riparian zones along the East River and West River in Ejina. The plant xylem water, soil moisture, rainwater, stream water and groundwater were taken and pretreated during the growing season in 2015-2016, and the stable oxygen isotope ratio (δ18O) for each water sample was measured. The δ18O of plant xylem water and soil moisture were compared to estimate the dominant depth of root water uptake, and the linear-mixed model called "IsoSource" were applied to determine plant water sources and quantify their proportions. Important findings: This study indicated that the main recharge sources for P. euphratica and T. ramosissima were stream water and groundwater. The contributions of rain water to them was negligible due to the limited amount and the shallow infiltration depth of local rainfall. As affected by groundwater level fluctuation, soil physical properties, as well as lateral and vertical recharge of stream water on soil moisture, the dominant depth of root water uptake spatially varied. However, the relative contributions of stream water or groundwater to plant water sources did not change significantly across space. Populus euphratica used more stream water (68%), while T. ramosissima used more groundwater (65%). Plant water sources were sensitive to environmental flow controls. The contributions of stream water to the water sources of the two species went up to 84% and 48% for P. euphratica and T. ramosissima respectively during the discharge period, but dropped to 63% and 30% during the non-discharge period. On the other hand, the contributions of groundwater decreased to 16% and 52% during the discharge period, but increased to 37% and 70% during non-discharge period. It is noteworthy that the high similarity of δ18O between stream water and groundwater due to extensive water exchange in the riparian zone made increase the uncertain in quantifying plant water sources.     

Soil water content and nitrogen differentially correlate with multidimensional leaf traits of two temperate broadleaf species

The variation and correlation of leaf economics and vein traits are crucial for predicting plant ecological strategies under different environmental changes.However,correlations between these two suites of traits and abiotic factors such as soil water and nitrogen content remain ambiguous.We measured leaf economics and vein traits as well as soil water and nitrogen content for two different shade-tolerant species(Betula platyphylla and Acer mono) in four mixed broadleaved-Korean pine(Pinus korai...     

Importance of functional classification in the use of carabids for the environmental risk assessment of the GE crops and other agricultural practices

Carabids(Coleoptera:Carabidae)seem to be suitable bioindicalors of the environmental impacts of novel agrotechnologies,including deployment of the genetically engineered(GE)crops.In this article,we describe our effort to employ carabids in the environmental risk assessment(ERA).GE maize MON88017,its near-isogenic hybrid nontreated or treated with the soil insccticide chlorpyrifos,and two reference hybrids were used to compare three different ways how to utilize carabids in ERA.The analysis of abundance of all captured carabids or of the most abundant carabid specics did not disclose any differences between the treatments.The analysis based on the categories of functional traits revealed distinct fecatures of some treatments and proved suitable for ERA because it permitted field data transportability in spite of different species compositions.Our results indicate that GE maize has no detrimental environmental effecl,On the other hand,we found significant trends toward lower abundance and lower species number(including analysis of all carabid species together)in plots treated with the insecticide,and some tendencies to higher abundance and higher species number in plots sown with the reference hybrid PR38N86.Using functional group indicators alows identification of unintended changes in ecological functions of agroecosystem and comparability across geographics.We recommend data evaluation at the level of the categories of functional traits in ERA of GE crops and other agricultural practices.     

Partitioning of soil respiration components and evaluating the mycorrhizal contribution to soil respiration in a semiarid grassland北大核心CSCD

Aims Soil respiration component partitioning is pivotal to understand the belowground carbon (C) cycle. Mycorrhizal fungi have been proven to play an important role in the soil C turnover, but only a few studies have been conducted to quantify the contribution of mycorrhizal respiration to total soil respiration in grassland ecosystems. Methods The mini-trenching mesh method was applied to partition soil respiration components of a semi-arid grassland in Inner Mongolia. A shallow collar (measuring soil total respiration), a deep collar (excluding roots and mycorrhizal hypahe) and a deep collar with 40 μm pore mesh window (excluding roots but not mycorrhizal hyphae) were installed in each plot. Soil respiration rate of each collar was measured every two weeks during the growing season from 2014 to 2016. The differences in the rate of soil respiration among different type of collars were used to partition the components of soil respiration. Important findings The results showed that the contribution of heterotrophic, root and mycorrhizal respiration to total soil respiration was 49%, 28%, and 23%, respectively. Across the three years, the proportion of mycorrhizal respiration varied from 21%-26%, which is comparable with the results reported by other studies recently. Our results demonstrated that the mini-trenching mesh method is a suitable method for separating mycorrhizal respiration component in grassland ecosystems. Evaluating the contribution of mycorrhizal respiration to total soil respiration is very important for predicting the responses of soil carbon release to future climate change. © 2018 Editorial Office of Chinese Journal of Plant Ecology. All rights reserved.     

Progress in the Study of Molecular Genetic Improvements of Poplar in China

The poplar is one of the most economically important and intensively studied tree species owing to its wide application in the timber industry and as a model material for the study of woody plants. The natural resource of poplars in China is replete. Over the past 10 years, the application of molecular biological techniques to genetic improvements in poplar species has been widely studied in China. Recent advances in molecular genetic improvements of poplar, including cDNA library construction, gene cloning and identification, genetic engineering, gene expression, genetic linkage map construction, mapping of quantitative trait loci （QTL） and molecular-assisted selection, are reviewed in the present paper. In addition, the application of modern biotechnology to molecular improvements in the genetic traits of the poplar and some unsolved problems are discussed.     

Characteristics of soil water distribution and evaluation of recharge rate under different grazing history in the Xilin Gol Steppe北大核心CSCD

Aims In the Xilin Gol Steppe, human-induced grassland degradation and land desertification are becoming increasingly severe. Critical evaluation of its impact on soil water and recharge rate is important for sustainable management of soil health and water resources in the region. Methods In order to determine the effect of different grazing history on dynamics of deep soil moisture contents and precipitation infiltration in the Xilin Gol Steppe, three sites with different grazing history (ungrazed since 1979 or UG79, ungrazed since 1999 or UG99, and continuously grazed or CG) were selected with two sampling spots for each site. The precipitation infiltration was estimated using the chloride mass balance method. Important findings The results showed that: 1) Average soil water content of 0–5 m was 7.1%, 6.9%, and 6.3% for UG79, UG99, and CG, respectively, with no significant difference. In the soil layer of 0–2 m, the soil water content of UG79 was 26.6% and 33.7% higher than that of UG99 and CG, respectively. The soil water content of UG79 was significantly higher than that of UG79 and UG99 (p < 0.05) with no significant difference between UG99 and CG. The soil water storage capacity of UG79 was 87.19 mm higher than UG99 and 82.52 mm higher than CG. In the deep layer of 2–5 m, no significant difference in the soil water content and the water storage among different grazing history. 2) The factors influencing soil water differed among different grazing treatments. The soil water content was mainly affected by the vegetation conditions and soil properties for the 0–2 m soil layer, but by the composition of soil particles for the 2–5 m soil layer. The effect of soil organic matter (SOM) content on soil water increased with time without grazing. Soil water content of the entire soil profile of UG79 was significantly correlated with soil texture and SOM content (p < 0.01). Soil water content of 0–2 m was significantly correlated with SOM content (p < 0.01), soil water content of 2–5 m was significantly correlated with the soil texture (p <0.01), but soil moisture content of UG99 and CG had no significant correlation with SOM content. 3) Annual recharge rate was 5.64, 3.54, and 2.45 mm·a –1 for UG79, UG99 and CG, respectively. The recharge rate increased by 44.5% and 130.2% for the site without grazing for 15 and 35 years, respectively. The recharge rate in the study area ranged from 1.95 to 7.61 mm·a –1 , accounting for only 0.55%–2.13% of the precipitation. In summary, ungrazing treatment can increase soil water retention, total water storage capacity, and recharge. © 2018 Editorial Office of Chinese Journal of Plant Ecology. All Rights Reserved.     

Are allometric model parameters of aboveground biomass for trees phylogenetically constrained?OA

Knowledge of which biological and functional traits have,or lack,phylogenetic signal in a particular group of organisms is important to understanding the formation and functioning of biological communities.Allometric biomass models reflecting tree growth characteristics are commonly used to predict forest biomass.However,few studies have examined whether model parameters are constrained by phylogeny.Here,we use a comprehensive database(including 276 tree species) compiled from 894 allometric bio...     

Impacts of methamidophos, copper, and their combinations on bacterial community structure and function in black soil

The potential ecotoxicologial risks of methamidophos, copper, and their combinations on microbial community of black soil ecosystem in the Northeast China were assessed in species richness and structures by using 16S rDNA-PCR-DGGE analysis approach, and functional characteristics at community levels by using BIOLOGGN system analysis method as well as two conventional methods(DHA and SIR). All results of DGGE banding fingerprint pat-terns(amplified by bacterial specific 16S rDNA V3 high variable region universal primer) indicated that the species richness of bacterial community in tested soil was significantly decreased to different extents by using different concentrations of single methamidophos, copper, especially some of their combinations had worse effects than their corresponding single factors. In addition, the structures of soil bacterial community had been disturbed under all stresses applied in this study because of the enrichment of some species and the disappearance of other species from the b     

Toward a general evaluation model for soil respiration (GEMSR)

Soil respiration is an important component of terrestrial carbon budget. Its accurate evaluation is es- sential to the study of terrestrial carbon source/sink. Studies on soil respiration at present mostly focus on the temporal variations and the controlling factors of soil respiration, but its spatial variations and controlling factors draw less attention. Moreover, the evaluation models for soil respiration at present include only the effects of water and heat factors, while the biological and soil factors controlling soil respiration and their interactions with water and heat factors have not been considered yet. These models are not able to accurately evaluate soil respiration in different vegetation/terrestrial ecosystems at different temporal and spatial scales. Thus, a general evaluation model for soil respiration (GEMSR) including the interacting meteorological (water and heat factors), soil nutrient and biological factors is suggested in this paper, and the basic procedure developing GEMSR and the research tasks of soil respiration in the future are also discussed.     

Spatio-temporal dynamics of two alpine treeline ecotones and ecological characteristics of their dominate species at the eastern margin of Qinghai-Xizang Plateau北大核心CSCD

Aims Temperature limit is the main cause of alpine treeline formation. Therefore, it is important to understand the response mechanisms of alpine treeline as well as their tree species under the global climate change. The present study focused on the spatio-temporal dynamics of treeline and ecological characteristics of the tree species in two treeline ecotones. Methods Two vertical belt-transect plots were established in each treeline ecotone of the Zheduo Mountain and Jianziwan Mountain of the eastern Qinghai-Xizang Plateau. Top and bottom of each transects were lain between species line and forest line, respectively. Detailed information of each tree species treeline, including species name, latitude, longitude, height, age, base diameter, and coordinates, was recorded accordingly. Important findings The temperatures of the two research areas have increased during the past 58 years. The precipitation has decreased slightly in both the Zheduo Mountain and Jianziwan Mountain. The age structure of Abies fabri from the Zheduo Mountain and A. squamata from the Jianziwan Mountain showed a reversed “J” shape curve and a bimodal shape, respectively. Within the two transects, due to the limitation of seed diffusion, the dominate species showed aggregated distributions at the small scale. At the large scale, A. fabri was aggregated at the Zheduo Mountain, while A. squanmata of the Jianziwan Mountain was randomly distributed due to the impact of surrounding environmental factors. Both tree height and base diameter decreased with the increase of elevation. The fir trees (Abies spp.) at the upper part of the treeline ecotone presented an allometric growth, whose height growth rate was higher than that of base growth, while the relationships between height growth and base growth were isometric at almost mid and lower part of the treeline ecotone. Compared with 10 years ago, there was no significant change at the position of treeline and tree species line of the Zheduo Mountain and the Jianziwan Mountain, neither of the tree density in the Jianziwan Mountain. However, the number of trees in the Zheduo Mountain increased by about 25%. Compared with 20 years ago, tree species lines of the Zheduo Mountain and Jianziwan Mountain were shifted upwards by 50 and 30 m, respectively. Besides, their treeline positions were increased by 75 and 40 m, respectively. Furthermore, the number of trees also increased significantly by 220% and 100%, respectively. Therefore, the treeline and its constructive species are mainly affected by temperature at the large spatio-temporal scale, while influenced by temperature and ambient environment at the small spatio-temporal scale. © Chinese Journal of Plant Ecology.