Late Succession Research Articles

Are reproductive traits of dominant species associated with specific resource allocation strategies during forest succession in southern China?

Plant reproductive traits have often evolved to optimize plant fitness under different environmental conditions, and their relationships with vegetative functional traits reflect more general plant reproduction and resource allocation strategies. How those relationships change during succession remains unclear. Here, we investigated the relationships between 8 reproductive traits and 18 functional traits of leaves, stems and whole plants during succession of a subtropical forest. We found that most leaf traits of dominant species were associated with seed/fruit dispersal mode and pollination pattern in the early successional forest, while with flower and fruit phenology in the middle and late successional forests. Plant reproduction traits were associated with specific resource utilization strategies during succession, i.e., plants with acquisitive resource utilization strategies tended to have long-distance fruit dispersal in the early succession, while with conservative resource utilization strategies tended to have early flowering (fruiting) or a long flowering (fruiting) period in the late succession. Our results indicate that acquisitive species may invest less energy and resources on reproduction in early succession, and that the conservative species may invest more energy and resources on reproduction in late succession.

Abstract P143: Late Success in Weight Loss Trials: Do Participants Start Losing Weight After 6 Months?

Background: Weight loss programs often start with an initial phase of intensive lifestyle coaching to facilitate early weight loss, with a typical weight loss goal of ≥ 5%. While early weight loss is associated with long-term weight loss success, less is known about those who do not lose weight in the initial phase. This study examines those without initial weight loss success, but lose weight later. Methods: Analyses included 346 obese adults from the POWER Hopkins weight loss trial and 673 overweight to obese adults from the PREMIER hypertension control trial. Mutually exclusive categories are based on weight loss success (≥ 5% reduction from baseline) at 6m and 12m: continued success (success 6m and 12m); regainer (success 6m then regained 12m); no success (no success 6m or 12m); and late success (12m success only). Results: No success (NS) was the most common category among control and intervention participants in both studies (see table). There were low rates of late success (LS) in POWER (intervention 5%, control 7%, p=.25) and PREMIER (intervention 5%, control 8%, p=.75). Within the POWER intervention, LS and NS were similar in age, sex, race, and baseline weight. Coaching contact rates were similar at 1-6m (LS 64%, NS 57%, p=.49) and 7-12m (LS 45%, NS 46%, p=.89). Within the PREMIER intervention LS had a lower baseline weight than NS (89 vs 99 kg, p=.01), but were similar in age, sex, and race. Coaching contact rates are similar at 1-6m (LS 77%, NS 72%, p=.23) and 7-12m (LS 66%, NS 62%, p=.58). Conclusion: Given the small fraction of intervention participants with late success (only 5%), alternative strategies are needed to address the large fraction of persons without initial weight loss success.

Boreal Forest Floor Greenhouse Gas Emissions Across a Pleurozium schreberi-Dominated, Wildfire-Disturbed Chronosequence

The boreal forest is a globally critical biome for carbon cycling. Its forests are shaped by wildfire events that affect ecosystem properties and climate feedbacks including greenhouse gas (GHG) emissions. Improved understanding of boreal forest floor processes is needed to predict the impacts of anticipated increases in fire frequency, severity, and extent. In this study, we examined relationships between time since last wildfire (TSF), forest floor soil properties, and GHG emissions (CO2, CH4, N2O) along a Pleurozium schreberi-dominated chronosequence in mid- to late succession located in northern Sweden. Over three growing seasons in 2012–2014, GHG flux measurements were made in situ and samples were collected for laboratory analyses. We predicted that P. schreberi-covered forest floor GHG fluxes would be related to distinct trends in the soil properties and microbial community along the wildfire chronosequence. Although we found no overall effect of TSF on GHG emissions, there was evidence that soil C/N, one of the few properties to show a trend with time, was inversely linked to ecosystem respiration. We also found that local microclimatic conditions and site-dependent properties were better predictors of GHG fluxes than TSF. This shows that site-dependent co-variables (that is, forest floor climate and plant-soil properties) need to be considered as well as TSF to predict GHG emissions as wildfires become more frequent, extensive and severe.

Effects of competition and phosphorus fertilization on leaf and root traits of late-successional conifers Abies fabri and Picea brachytyla

Leaf and root systems are known to show a high degree of developmental plasticity in response to the local environment. However, few studies have investigated simultaneously the leaf and root traits as affected by competition and phosphorus (P) fertilization, especially in connection with the primary succession. We investigated morphological and physiological responses to different competition treatments (intra- vs. interspecific competition) and P regimes in seedlings of Abies fabri and Picea brachytyla, collected from the late succession stage Hailuogou glacier retreat area. A. fabri had a greater total chlorophyll content and specific leaf area (SLA), higher leaf nitrogen (N) and P concentrations, as well as a higher water use efficiency (assessed by the carbon isotope composition, δ13C) and N absorption relative to P. brachytyla under P fertilization conditions, and its total biomass responded more strongly to P fertilization, especially under interspecific competition. P fertilization decreased the specific root length (SRL) and ectomycorrhizal infection in both species and specific root tip density in P. brachytyla but it had no effect on the average root diameter. We concluded that similar changes in root characteristics, but the superior performance of above-ground traits in A. fabri in response to P availability, especially under competition, explain the greater competitive capacity of A. fabri at final stages of succession. These findings highlight the influence of soil nutrition availability and competition on the functional traits of plants and contribute to the understanding of the role of relative modifications in leaf and root traits during succession.

Forest Fire and Indigenous Sami Land Use: Place Names, Fire Dynamics, and Ecosystem Change in Northern Scandinavia

During the last two centuries, fire suppression has critically modified boreal ecosystems in northern Scandinavia and has undoubtedly affected indigenous Sami land use. We inventoried Sami toponyms referring to fire in a municipality located in Swedish Sápmi, and investigated their past and present meanings by analyzing Sami dictionaries and conducting semi-structured interviews with Sami reindeer herders. We use toponyms based on the Sami word ‘roavve’ - a lichen-rich pine-heath that has burned - as a description of past ecosystems to inventory understory and tree vegetation and date the last occurrence of fire in 15 ‘roavve’ places. The inventories showed that some ‘roaave’ places have developed a late succession vegetation type, reducing their suitability for reindeer grazing. We argue both that fire suppression strongly influences the ecological trajectory of these sites and that one must take into account ethnoecological considerations when using toponyms as ecological markers to fully understand their meanings and avoid misinterpretation.

海岛植物不同演替阶段植物功能性状与环境因子的变化规律

PDF HTML阅读 XML下载 导出引用 引用提醒 海岛植物不同演替阶段植物功能性状与环境因子的变化规律 DOI: 10.5846/stxb201807051468 作者: 作者单位: 福建农林大学,福建农林大学,福建农林大学,云南大学,福建农林大学 作者简介: 通讯作者: 中图分类号: 基金项目: 福建省自然科学基金面上项目（2018J01699）；国家自然科学基金项目（31800401）；福建省教育厅科技项目（JAT170198） Summary of changes in plant functional traits and environmental factors in different successional stages of island plants Author: Affiliation: Fujian Agriculture and Forestry University,Fujian Agriculture and Forestry University,Fujian Agriculture and Forestry University,,Fujian Agriculture and Forestry University Fund Project: 省、部研究计划基金, 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:植物功能性状与环境之间的关系是功能性状研究的重点，环境因子驱使植物功能性状发生变化，进而推动群落发生演替。以平潭岛4个不同演替阶段的森林植被（灌草丛、针叶林、针阔混交林、常绿阔叶林）为研究对象，结合不同群落演替阶段的物种特征和群落结构，分析海岛不同演替阶段茎、叶功能性状的变化规律，以及功能性状与环境因子的关系。结果表明：（1）随着演替的进行，土壤养分和水分逐渐增加，土壤pH逐渐下降。比叶面积（SLA）、叶片氮含量（LNC）、叶片磷含量（LPC）、茎氮含量（SNC）、茎磷含量（SPC）下降后上升，叶厚度（LT）、叶片碳含量（LCC）、茎碳含量（SCC）与之相反，叶干物质含量（LDMC）、茎组织密度（STD）逐渐上升。（2）冗余分析表明，演替早期植物主要分布在土壤pH、容重高的贫瘠环境，拥有较高SLA、SNC、SPC、LPC的性状组合；演替后期植物主要分布在土壤养分和水分高的肥沃环境，拥有较高的STD、LDMC、LCC、LNC的性状组合。其中，土壤有机质和全氮含量是影响海岛植物演替过程中功能性状变化的关键环境因子。研究海岛植物功能性状与环境之间的关系随演替的变化规律，探讨各演替阶段功能性状和环境特征，以及功能性状如何响应环境变化。旨在为今后选择合适的树种进行海岛植被修复和重建提供依据。 Abstract:The relationship between plant functional traits and environment is the focus of functional traits research. Environmental factors drive the changes in plant functional traits, which in turn promote community succession. Based on the forest vegetation of four different succession stages (shrub-grassland, coniferous forest, mixed wood, and broadleaf forest) in Pingtan Island, this study combined the species characteristics and community structure of different community successional stages. We analyzed the changes in stem and leaf functional traits in different succession stages of island plants. Moreover, we explored the relationship between plant functional traits and environmental factors. The results showed the following. (1) With progress in succession, soil nutrient and water content gradually increased and the soil pH gradually decreased. The specific leaf area (SLA), leaf nitrogen content (LNC), leaf phosphorus content (LPC), stem nitrogen content (SNC), and stem phosphorus content (SPC) decreased initially, and then increased, Meanwhile, the leaf thickness (LT), leaf carbon content (LCC), and stem carbon content (SCC) increased initially, and then decreased. The leaf dry matter content (LDMC) and stem tissue density (STD) gradually increased. (2) The redundancy analysis showed that the early succession plants were mainly distributed in barren environments with high soil pH and high bulk density, and they presented higher SLA, SNC, SPC, and LPC. Plants in the late succession stages were mainly distributed in fertile environments with high soil nutrient and water content, and they presented higher STD, LDMC, LCC, and LNC. Therefore, soil organic matter and total nitrogen are the important environmental factors that affect the functional traits of island plants succession. We studied the relationship between plant functional traits and environment along with the changes in succession, understood the functional traits and environmental characteristics of each succession stage, and revealed how plant functional traits adapted to the environmental changes. The study provides the basis for the selection of suitable tree species for island vegetation restoration and reconstruction in the future. 参考文献 相似文献 引证文献

The Impact of Anthropogenic Intervention on the Walauwewaththa Wathurana Fresh Water Swamp Forest in Sri Lanka

Swamp forests are considered as the late succession stage of a freshwater marsh ecosystem and it is the rarest wetland type in Sri Lanka, rich in biodiversity thus providing a number of ecosystem services. The Walauwewatta Wathurana has been identified as the most dynamic fresh water ecosystem in Sri Lanka. These rare forest ecosystems have been subjected to degradation over the past decades due to various reasons especially anthropogenic activities. A study was conducted to explore the magnitude of these impacts caused by anthropogenic activities. A household survey was conducted using a structured questioner and Participatory Rural Appraisals (PRA) and discussions were made to gather information from the people living close by the swamp. Data analysis based on both quantitative and qualitative techniques. It was revealed that, a large number of activities carried out in the surrounding area of the forest by the neighboring communities directly or indirectly were related to their livelihoods as well as for their daily household needs. The richness of the species and the abundance have decreased over the past two decades due to the unsustainable fishing activities, contamination of agro-chemicals as well as chemical effluents of rubber based industries, sand mining, bamboo and rattan industries located around the forest area. Therefore the Wathurana fresh water swamp forest has been subjected to degradation due to anthropogenic activities. Conservation strategies should be implemented to strengthen the sustainability of the ecosystem services provided by this freshwater swamp forest. KEYWORDS: Anthropogenic Activities, Degradation, Ecosystem, Fresh Water Swamp Forest, Impact

A Coach’s Perception: Major Factors influencing Late Goal-Scoring-Patterns in Maltese Football

Beyond its basic simplicity, football, is a very complex game. There is no one particular way of playing or method of training that can bring about results. The aim of football is to score more or concede fewer goals than the opponent. With goals being the crucial element, statistics prove that a high percentage are scored late in the game. This study set out to identify and demonstrate that the number of goals scored in the last fifteen minutes of a ninety-minute football game in top football competitions are higher than in any other fifteen-minute segment in the game. The study also investigates the correlation between the highest percentage of late goals and success which is measured as the final placement in the league table. It also attests that the same goal-scoring patterns are relevant to the Maltese Premier Division, which is considered to be at a lower level of play compared to other top leagues. Consequently, the study identifies the main factors which typically influence such goal-scoring patterns as perceived by local coaches. These factors are physiology, technical-tactical elements, and the team’s psychological attitude towards the game, players’ experience, club finances, and unfavourable circumstances which lead to an uneven level of play. Lastly, the paper identifies the different perceptions of these factors based on coaches’ qualifications and coaching experience at senior level. This paper could assist coaches in planning and preparing training sessions, with the hope of maximizing their training efficiency and effectiveness. It can also assist coaching course-developers and coordinators to enhance the level of the courses by altering content, assessment criteria, and topics.

The formal method in Germany and Russia: the beginnings of European psycholinguistics

Abstract German–Austrian psychology is a direct source of the European formalism movement both in the German context (Germany, Austria) as well as in Russia. This interest of the formalists in the corporeal component of linguistic and literary production has resulted in a particular research stream, which could be defined as a ‘linguo-somatic orientation’. In particular, this is the case of Alois Riegl’s [1] perceptive ‘tactile–optical’ method; Adolf von Hildebrand’s [2] architectonic conception; Konrad Fiedler’s [3] ‘sensorial aesthetics’; W. Wölfflin’s [4] ‘basic concepts’ of the art history, W. Worringer’s [5] psychological arts typology as well as Oskar Walzel’s sound-corporeal poetics elaborated during 1920 [6]. Within Russian formalism, psychological notions (such as ‘representation’, ‘sensation’, ‘apperception’, ‘series’, ‘clear and dark zones of consciousness’, ‘verbal gestures’ and ‘sound gestures’) are fundamental in nearly all the formalist conceptions (Viktor Šklovskij, Evgenij Polivanov, Lev Jakubinskij, Osip Brik, Boris Eixenbaum and Jurij Tynianov). This psychological background constitutes a rather heterogeneous constellation composed of psychological aesthetics and psychological linguistics of the second half of the 19th century. Independently of its intrinsic theoretical values, the formalist way of thinking about language and literature is based on the implicit dominance of psychology, which takes its sense only with respect to the German cognitive tradition, appropriated by the Geisteswissenschaften of this time. In this respect, European formalism participates in the large movement of psychologisation of the humanities. To this extent, the case of Russian formalism is really representative: it invites the rethinking of the genealogy of European structuralism in general. This accumulation of conceptual tools borrowed from the German psychological tradition also reveals a cognitive charge of the formalist theories. The latter constitute a conceptual link between the properly psychological past of the European Geisteswissenschaften and the ‘cognitive’ future of the actual research programmes. Beyond the borrowing of conceptual tools from the psychological trend, the formal method has found in psychology its inspiration for producing new models of analysis. This intrinsically cognitivist dimension of the formalist programme explains its late success during the 1950s–1960s, the period often and abusively called the period of the cognitivist revolution. In reality, it deals with the re-emergence of the research programme of the cognitivist sciences, rather exhaustively formulated by the German psychological tradition..

Features of the Stand and Deadwood in Postfire Aspen and Birch Forests in Northern Urals

By now, most of the forests in the European part of Russia have been transformed by drastic fires and clear cutting. Significant areas of primary dark coniferous forests in the Northern Urals have been replaced by either birch or aspen stands. These communities pass different stages of secondary succession. They remain understudied despite their wide occurrence. We consider the composition and structure of the tree story and deadwood in two postfire communities (80- and 120-years old). Both fires were initiated from the slash-and-burn cultivation, as has been the practice up to the mid-20th century. The composition of the stands in these communities indicates the gradual replacement of early succession tree species—aspen and willow—by late succession spruce and fir. Weibull function was applied to fit the distribution of diameters of the trees. We show that these communities do not differ by most indicators of stand and deadwood structures and characterize the same successional stage.

Juxilyocypris kempfi, a new species of the genus Juxilocyprus (Ostracoda, Ilyocyprididae) from the Late Pleistocene-Holocene of Eastern Adriatic coast (Croatia)

ABSTRACT A new non-marine species of the ostracod genus Juxilyocypris (Kempf, 1967) is described from the late Pleistocene and Holocene sedimentary succession of Lake Vrana (Dalmatia) and Pirovac Bay in the central part of Eastern Adriatic coast in Croatia. The species has been previously recorded as Juxilyocypris cf. schwarzbachi from Lake Vrana (Dalmatia). Juxilyocypris kempfi sp. n., is a cold-temperate species of flooded karst polje habitats characterized by clastic carbonate-rich facies, followed by an organic-rich, low-energy wetland, and periodically shallow waters with muddy bottoms. The presence of a new species of the genus Juxilyocypris (Kempf, 1967) in Croatia extends the known biostratigraphical and biogeographical range of this taxon.

Transconjunctival Triamcinolone Injection for Upper Lid Retraction in Thyroid Eye Disease-A New Injection Method.

To evaluate the role of transconjunctival triamcinolone acetonide (TA) injection in the management of upper eyelid retraction in thyroid eye disease. Retrospective interventional review of all patients who underwent transconjunctival TA injection (40 mg/mL) for thyroid eye disease-related upper eyelid retraction from January 2010 to December 2016 in a single tertiary institution. The present study comprised 2 groups: Patients receiving only TA injection (group 1), and patients receiving both TA injection and other immunosuppressive therapy (group 2). There were a total of 99 patients and 135 eyes. Group 1 comprised of 36 eyes (26.7%), while group 2 comprised 99 (73.3%). Normalization or improvement of margin reflex distance 1 was seen in 77.4% and 97.2% of group 1 patients at early and late review, respectively, and 77.6% and 87.8% of group 2, respectively. Absence or improvement in International Thyroid Eye Disease Society inflammatory index was seen in 83.9% and 86.1% of group 1 at early and late review, respectively, and 71.9% and 76.8% of group 2, respectively. Both active (73.7%) and inactive (79.3%) groups showed good early success for improvement in margin reflex distance 1, with increased late success and no significant difference between the groups. For International Thyroid Eye Disease Society inflammatory index, the active group had better early and late success than the inactive group, with the difference being significant (P = 0.002) for late success. Transconjunctival TA injection is an effective treatment option for thyroid eye disease-related upper eyelid retraction, as a primary and adjunctive treatment, in both active and inactive thyroid eye disease patients.

Change in soil bacterial community during secondary succession depend on plant and soil characteristics

Secondary succession has great impact on plant and soil characteristics, however, the trends of microbial patterns and the influencing factors during grassland succession without human disturbance remains unclear. Therefore, we investigated the changes of bacterial community in sloped farmlands abandoned for 0, 20, 30, and 40 years (GL-0 yr, GL-20 yr, GL-30 yr, and GL-40 yr). Additionally, plant traits (coverage, diversity, richness, evenness, biomass, and biomass carbon) and soil nutrients were also determined. The results showed that soil bacterial alpha diversity was positively and significantly correlated with the succession time, and the secondary succession greatly affected soil bacterial beta diversity, in contrast, the effects on soil bacterial beta diversity at the late succession time (GL40 and GL30) were larger than that at the early succession time (GL20). For the bacterial taxa, the dominant phyla including Actinobacteria (34.8%), Proteobacteria (26.0%), Acidobacteria (15.0%), Chloroflexi (7.5%), Gemmatimonadetes (8.7%), Nitrospirae (1.6%), Bacteroidetes (2.1%), Verrucomicrobia (1.1%), and Planctomycetes (1.0%) were found. Particularly, the relative abundance of Proteobacteria was higher at the late time (RP40), while the Actinobacteria was higher at the early time (RP20). Such different responses of bacterial diversity and taxa were largely explained by plant traits and soil nutrients, especially for TOC and TN. Collectively, our results indicate that plant secondary succession shifts the bacterial community structure, largely driven by changes in soil nutrients and plant diversity and composition, and also supported the growing view that soil bacterial community are the key determinants of aboveground and belowground linkages that functionally control terrestrial ecosystems.

Stable and radio-isotopic signatures reveal how the feeding habits of ants respond to natural secondary succession in a cool-temperate forest

Ants are known to have various feeding habits and play important roles in many terrestrial ecosystems. However, little is known about how the feeding habits of each ant species are affected by the environmental changes associated with forest succession. In this study, we examined how feeding habits as well as the species composition and food preference of ants would respond to 105-year-old natural secondary succession of a cool-temperate forest. Stable carbon and nitrogen isotopes and radiocarbon were used to infer the feeding habits. The species richness was not affected by forest stand age. Redundancy analysis indicated that stand age, litter N concentration, and soil microbial respiration had significant relationships with the ant species composition. The bait experiments showed that honey bait became more attractive to ants relative to tuna bait in late succession. This was probably associated with changes in available food resources, such as nectar, during succession. Although the isotopic signatures differed significantly among the sample types (i.e., ant species, canopy leaves, and leaf litter), they were not significantly affected by forest stand age or by the interaction between sample types and stand age. This indicates that the ants showed consistent differences in feeding habits among the species during succession. Our results suggest that despite great changes in vegetation, each ant species would maintain functional roles in C and N flows during forest succession.

Floodplain succession pattern along Budhi-Rapti River bank, Chitwan, Nepal

Riverine floodplain is one of the most productive lowland ecosystems in Nepal. However, floodplain ecology is less understood due to its fluctuation. Budhi-Rapti River in Chitwan, central Nepal formed a floodplain along the Khorsor zone of Barandabhar corridor. This study was carried out to understand the floodplain ecosystem development after plant succession. The space for time substitution method of vegetation sampling was adopted in order to sample the floodplain created at different chronosequence. The floodplain that lies perpendicular to and 200 m away from the Budhi-Rapti river was sampled. Systematic sampling was done along two parallel transects, almost 200 m apart from each other. Sampling along the transect started right after 200 m away from the Budhi-River bank. Initial position of these transects towards Budhi-Rapti river was believed to be the youngest floodplain, which slowly getting older after passing away from the river. Abundance of vascular plant species was recorded in sample plots of 20 × 20 m each subdivided equally into 4 subplots (each of 100 m2). Along each transect, vegetation data was recorded from a series of 20 plots, placed 50 m apart from each other. Successional scores were calculated and utilized as environmental variables after applying non-metric multi-dimensional scaling (NMDS) through metaMDS. Total and life form (herbs, shrubs and trees) richness patterns were calculated. Altogether, 158 species of vascular plants under 60 families and 136 genera were recorded. Gramineae was the richest family followed by Leguminosae, Asteraceae and Cyperaceae. Total species richness showed significant negative correlation with the NMDS1 and NMDS2, which justified a convergent pattern of succession. Herb, orchid and shrub species richness also showed significant declining pattern with NMDS1. Persicaria barbata, Parthenium hysterophorus, Ageratum conyzoides and Typha angustifolia were early succession indicator species; whereas Albizia lucidior, Miliusa velutina, Ficus hispida, Bauhinia purpurea and Brassaiopsis glomerulata were the late succession tree species. This study agreed with the convergent model of succession.Botanica Orientalis – Journal of Plant Science (2017) 11: 12–26

Late Quaternary Environments of the Teton Mountains, Wyoming: A Pollen Record from Green Lake

Late Quaternary forest succession in Wyoming’s Rocky Mountains, occurred in random patterns, because it reflects differences between the Glacial vegetation at lower elevations on the east vs. the west of the Rockies, as well as along the mountain crest to the south. Differential melting of mountain glaciers resulted in differences in the timing of recolonization. Significant variations in the composition of plant assemblages occurred due to delays in species’ arrival, and even in the exclusion of species. Holocene climate variability, especially ongoing global warming, added to the complex dynamics of plant assemblages with warm climate species replacing early Holocene, cooler climate species. The pollen record from Green Lake (located in a glacial cirque on the west side of the Teton Mountains in Teton County, Wyoming) addresses the local vegetation response from just before the fall of Mazama ash to the end of the middle Holocene warm period. Although the earlier portion of the pollen sequence records some of the last adjustments as some plant species were still arriving after de-glaciation, by the time Mazama ash fell it was climate variation that determined most of the dynamics observed in the Green Lake record. The results reveal a sequence of wetter and drier periods based upon the presence of diagnostic tree species. A moist late early Holocene was followed by a dry middle Holocene, which ended about 6,400 cal. B.P., and was followed between 5,000 to 2,800 cal. B.P. by a sequence of drier and moister climate episodes.

Growth Variations of Tree Saplings in Relation to Species Diversity and Functional Traits in a Tree Diversity Pot Experiment

Despite the accumulating evidence of the beneficial effects of diverse mixed species forests on ecosystem functioning and services, foresters in subtropical forest cultivation in China still prefer easily managed monocultures, which is also due to the complexity of mixed forests and the unknown underlying mechanisms related to relationships between biodiversity and forest growth. In a designed pot experiment, we selected two early-successional tree species (Pinus massoniana Lamb., Liquidambar formosana Hance.) and two late-successional tree species (Schima superba Champ., Elaeocarpus decipiens Hemsl.) and planted four saplings in one pot with regard to tree species diversity (monoculture, two species and four species mixtures), each combination replicated four times. In this three-year duration experiment, the effect of tree species diversity, tree identity, and functional traits on sapling growth (tree height, ground diameter, crown projection area), were analyzed. The results showed that the increments of ground diameter and crown projection area increased with tree species richness, whereas the mean tree height increment showed the opposite effect. This growth variation was species specific and related to functional traits (early or late succession), as the increments of the early successional tree species (P. massoniana Lamb. and L. formosana Hance.) had a positive correlation with tree species richness, while the late successional tree species (E. decipiens Hemsl. and S. superba Champ.) showed negative effects. In addition, our study provided evidence for the allometric differences between mixtures and monocultures, which have an important reference value on mixed-species forests.

The Impact of Anthropogenic Intervention on the Walauwewaththa Wathurana Fresh Water Swamp Forest in Sri Lanka

Swamp forests are considered as the late succession stage of a freshwater marsh ecosystem and it is the rarest wetland type in Sri Lanka, rich in biodiversity thus providing a number of ecosystem services. The Walauwewatta Wathurana has been identified as the most dynamic fresh water ecosystem in Sri Lanka. These rare forest ecosystems have been subjected to degradation over the past decades due to various reasons especially anthropogenic activities. A study was conducted to explore the magnitude of these impacts caused by anthropogenic activities. A household survey was conducted using a structured questioner and Participatory Rural Appraisals (PRA) and discussions were made to gather information from the people living close by the swamp. Data analysis based on both quantitative and qualitative techniques. It was revealed that, a large number of activities carried out in the surrounding area of the forest by the neighboring communities directly or indirectly were related to their livelihoods as well as for their daily household needs. The richness of the species and the abundance have decreased over the past two decades due to the unsustainable fishing activities, contamination of agro-chemicals as well as chemical effluents of rubber based industries, sand mining, bamboo and rattan industries located around the forest area. Therefore the Wathurana fresh water swamp forest has been subjected to degradation due to anthropogenic activities. Conservation strategies should be implemented to strengthen the sustainability of the ecosystem services provided by this freshwater swamp forest.

Functional traits associated with plant colonizing and competitive ability influence species abundance during secondary succession: Evidence from subalpine meadows of the Qinghai-Tibetan Plateau.

It is widely recognized that colonists and competitors dominate early and late succession, respectively, with selected species having different colonizing and competitive abilities. However, it remains unknown whether colonizing and competitive ability can determine species abundance directly over succession. The data for five key functional traits were collected (photosynthesis rate, leaf turgor loss point, leaf proline content, seed mass, and seed germination rate), which are direct indicators of plant competitive and colonizing abilities including growth, drought and cold stress resistance, dispersal, and seed dormancy. Here, we tested the effects of colonizing and competitive abilities on species abundance, by employing a linear mixed‐effects model to examine the shifts in the relationship between species abundance and these five colonization and competition‐related traits in species‐rich subalpine secondary successional meadows (at 4, 6, 10, 13 years of age, and undisturbed, respectively) of the Qinghai–Tibetan Plateau. The abundant species at the early‐successional meadows tend to have high photosynthetic rate, high leaf proline content, low seed mass, and seed germination rate for having high colonizing ability, but low competitive ability. By contrast, late‐successional communities tend to be dominated by species with high competitive ability, but low colonizing ability, indicated by large seeds, high seed germination rate, low photosynthetic rate, and leaf proline content. The observed directional shifts in the relationships between traits (photosynthetic rate, leaf proline content, seed mass, and seed germination rate) and abundance with successional age, bring two new understandings of community assembly during succession of subalpine meadows in the Qinghai–Tibetan Plateau. First, it discloses that the differences in species abundance over succession can be directly attributed to differences in colonizing and competitive abilities of different species. Second, it expands the effects of multiple life historical differences including growth, resource competitive ability, cold stress resistance, dispersal, and seed germination strategy, represented by functional traits on community assembly along succession, that is, from the species to the community level.

Hydro-chemical effects following restoration mowing in two rich fen plant communities

Mowing is a common management technique employed in Europe and North America to manage seral wetland plant communities to: (a) prevent development to late succession, (b) minimise internal eutrophication and (c) conserve biodiversity. However, little is known about the effect mowing has on water quality, and the duration of any effects. Therefore, mowing treatments were applied in two abandoned fen plant communities: a Schoenus nigricans-Juncus subnodulosus (SN) community (hand-cutting) and a Cladio-Molinietum (CM) community (machine mowing). Mowing took place once in each community across three sites in North Wales, U.K. Effects on water chemistry were followed for two years post mowing.