Vegetation Ecology Research Articles

Marcel van der Heijden.

Marcel van der Heijden.

Plant Trait Dataset for Tree-Like Growth Forms Species of the Subtropical Atlantic Rain Forest in Brazil

Plant functional traits have been incorporated in studies of vegetation ecology to better understand the mechanisms of ecological processes. For this reason, a global effort has been made to collect functional traits data for as many species as possible. In light of this, we identified the most common species of an area of 15,335 km2 inserted in the subtropical Atlantic Rain Forest in Southern Brazil. Then, we compiled functional trait information mostly from field samples, but also from herbarium and literature. The dataset presents traits of leaf, branch, maximum potential height, seed mass, and dispersion syndrome of 117 species, including trees, tree ferns, and palms. We also share images of anatomical features of branches used to measure wood traits. Data tables present mean trait values at individual and species level. Images of wood and stomatal features may be useful to assess other anatomical traits that were not covered in the data tables for the anatomical determination of species and/or for educational purposes.

Time-delay-induced dynamical behaviors for an ecological vegetation growth system driven by cross-correlated multiplicative and additive noises.

In this paper, the modified potential function, the stationary probability distribution function (SPDF), the mean growth time and the mean degeneration time for a vegetation growth system with time delay are investigated, where the vegetation system is assumed to be disturbed by cross-correlated multiplicative and additive noises. The results reveal some fact that the multiplicative and additive noises can both reduce the stability and speed up the decline of the vegetation system, while the strength of the noise correlation and time delay can both enhance the stability of the vegetation and slow down the depression process of the ecological system. On the other hand, with regard to the impacts of noises and time delay on the mean development and degeneration processes of the ecological system, it is discovered that 1) in the development process of the vegetation population, the increase of the noise correlation strength and time delay will restrain the regime shift from the barren state to the boom one, while the increase of the additive noise can lead to the fast regime shift from the barren state to the boom one. 2) Conversely, in the depression process of the ecological system, the increase of the strength of the correlation noise and time delay will prevent the regime shift from the boom state to the barren one. Comparatively, the increase of the additive and multiplicative noises can accelerate the regime shift from the boom state to the barren state.

Assessment for Artisanal gold mining impacts on vegetation ecology at Shire Districts

Assessment for Artisanal gold mining impacts on vegetation ecology at Shire Districts

Sap flow of black locust in response to short-term drought in southern Loess Plateau of China

Soil water shortage is a major factor influencing the ecology and hydrology of vegetation in China’s semihumid Loess Plateau. However, few studies have experimentally assessed how expected changes in precipitation will affect sap flow in semihumid forest ecosystems. In this study, we measured the sap flow of black locust (Robinia pseudoacacia Linn.) under ambient and drought (induced by throughfall exclusion) conditions in 2015 and 2016, and investigated the relationship between stand transpiration and environmental factors in the semihumid China’s Loess Plateau. Throughfall exclusion significantly decreased sap flux density and stand transpiration by 39% and 28%, respectively, in 2016, which may have been due to the cumulative droughts effect from both 2015 and 2016. Throughfall exclusion caused a significant reduction in soil moisture, leaf area index (LAI), and stem diameter. Stand transpiration was positively correlated with LAI (P < 0.01), but precipitation and soil moisture did not correlate with stand transpiration at a daily timescale, suggesting that LAI can be used as a proxy for stand transpiration. Our results highlight that precipitation must be considered when planting black locust in semihumid regions. These findings provide basic information about the management of water resources and vegetation restoration in the semihumid China’s Loess Plateau and possibly other water-limited regions around the world.

The Romanian Grassland Database (RGD): historical background, current status and future perspectives

This report describes the Romanian Grassland Database (RGD), registered under EU-RO-008 in the Global Index of Vegetation-Plot Databases (GIVD). This collaborative initiative aims to collect all available vegetation-plot data (releves) of grasslands and other open habitats from the territory of Romania to provide them for science, nationally and internationally, e.g. via the European Vegetation Archive (EVA) and the global database sPlot. The database mainly contains vegetation-plots from not only wet, mesic, dry, saline, alpine and rocky grasslands, but also other vegetation types like heathlands, mires, ruderal, segetal, aquatic and cryptogamdominated vegetation. Currently, 21,685 releves have mainly been digitised from literature sources (90%), while the remainder comes from individual unpublished sources (10%). We report on the background and history of the RGD, explain its Data Property and Governance Rules under which data are contributed and retrieved, and outline how the RGD can contribute to research in the fields of vegetation ecology, macroecology and conservation.

Environmental controls of raised-bog vegetation in the Baltic boreo-nemoral zone

Raised peat bogs harbor unique vegetation types in specific hydrological conditions. Environmental controls of peat bog vegetation are relatively well known for the boreal zone, while in the European boreo-nemoral zone healthy raised bogs are nowadays very rare. By contrast, Latvia, located in the transition zone between the nemoral and the boreal biomes, still has a large number of active raised bogs. The aim of the present study was to characterize the environmental controls on raised bog vegetation structure, species composition and ecology in Latvia. The study includes 17 raised bogs, where vascular plants, bryophytes and lichens were recorded in 480 sample plots and related to environmental variables (microtopography, litter cover, electric conductivity, pH, and macroelements Na, K, Ca, Mg and P in bog surface waters). The factor best explaining total species richness and composition was microtopography, which also affected most other explanatory factors. Thereby total species richness and cover were highest on hummocks. However, the importance and direction of the effects of microtopography and the other factors differed between vegetation groups. When disregarding microtopography, species composition was most strongly correlated with alkaline ions and litter cover and for bryophytes also with vascular plant cover. The present study is the first wide-scale study in Latvia relating raised bog vegetation to environmental conditions.

Mapping the model of ecological vegetation as potential malaria habitats in a malaria-endemic region in Oesao Village, kupang regency, Indonesia

Environmental risk factors, both physical and biological (e.g. ecology of vegetation/plants, forest), equally serve as the risk factors for Anopheles mosquitos breeding. This study was designed to determine a model of spatial mapping for the ecology of vegetation and the potential habitats for the Anopheles mosquitos. Descriptive epidemiological research was implemented to carry out the project, supported with a cross-sectional design. The research took place in Kupang regency, Oesao village, lasting for 2 months from October to November 2014. The ecology of the vegetation and all habitats of the mosquitos in Oesao village were regarded as the population of the research. They were purposively sampled. The vegetation mapping revealed that the land area for rice fields is 169 ha, coconut and banana tress 56.68 ha, maize 67.03 ha, vegetable plants 59.53 ha, forages 21.52 ha, and forests 16.24 ha. The results of the mapping also revealed that the mosquitos breeding sites entail paddy fields, swamps, irrigation channels, and damps. The ecology of all types of plants mapped serves as potential habitats for the Anopheles mosquitos breeding sites. Plant ecology is quite varied in the Oesao Village, as well as extensive areas of the plant that are closely linked to inadequate growth and development of mosquitoes and specific species of Anopheles, An. vagus and An. annularis.

Long-term investigations and experimental manipulations: Useful perspectives for applied vegetation studies

Long-term investigations and experimental manipulations: Useful perspectives for applied vegetation studies

Book review on two textbooks of vegetation ecology and a short discussion about the importance of local case studies in ecology textbooks

Book review on two textbooks of vegetation ecology and a short discussion about the importance of local case studies in ecology textbooks

Predicting temperate forest stand types using only structural profiles from discrete return airborne lidar

Light detection and ranging (lidar) data have been increasingly used for forest classification due to its ability to penetrate the forest canopy and provide detail about the structure of the lower strata. In this study we demonstrate forest classification approaches using airborne lidar data as inputs to random forest and linear unmixing classification algorithms. Our results demonstrated that both random forest and linear unmixing models identified a distribution of rainforest and eucalypt stands that was comparable to existing ecological vegetation class (EVC) maps based primarily on manual interpretation of high resolution aerial imagery. Rainforest stands were also identified in the region that have not previously been identified in the EVC maps. The transition between stand types was better characterised by the random forest modelling approach. In contrast, the linear unmixing model placed greater emphasis on field plots selected as endmembers which may not have captured the variability in stand structure within a single stand type. The random forest model had the highest overall accuracy (84%) and Cohen’s kappa coefficient (0.62). However, the classification accuracy was only marginally better than linear unmixing. The random forest model was applied to a region in the Central Highlands of south-eastern Australia to produce maps of stand type probability, including areas of transition (the ‘ecotone’) between rainforest and eucalypt forest. The resulting map provided a detailed delineation of forest classes, which specifically recognised the coalescing of stand types at the landscape scale. This represents a key step towards mapping the structural and spatial complexity of these ecosystems, which is important for both their management and conservation.

Hydnoid fungi of the family Bankeraceae – their assemblages and vegetation ecology in Central Europe, Czech Republic

Abstract The diversity of stipitate hydnoid fungi of the genera Bankera, Hydnellum, Phellodon and Sarcodon was studied at 92 microlocalities in the Czech Republic in 2010–2014. Their vegetation was documented by means of phytosociological releves. In total, 26 hydnoid species were found. Individual microlocalities hosted 1–6 hydnoid species. Frequent co-occurrence of certain species pairs or groups was revealed. Multivariate analyses were used to test community patterns between hydnoids and vegetation, divided into layers and plant functional groups. We confirmed the hypothesis that vegetation layers and functional groups have different effects on the individual hydnoid species. The occurrence of hydnoids is conditional especially on the dominant tree species. The main vegetation gradient of hydnoid sites is represented by the proportion of deciduous versus coniferous trees. Smaller trees in shrub and herb layers do not play a significant role except for spruce. Some hydnoids occur at sites with a species-rich herb layer, whereas others occur at sites with ericoid heaths and lichens, wet sites covered with hygrophilous mosses, or bare soils only covered by litter. Possible factors favouring hydnoids and causing their accumulation at small sites are outlined, e.g. facilitation, phylogenetic conservatism and alteration of tree dominants during succession. Habitat conditions creating “hydnoid site quality” are summarized including the character of the Czech hydnoid-richest sites.

Delay induced steady-state transition and stochastic resonance for an ecological vegetation growth system subjected to multiplicative and additive noises

In this paper, our aim is to investigate the steady state properties and stochastic resonance (SR) phenomenon for an ecological vegetation growth system with time delay induced by the multiplicative and additive noises. Numerical results show that the SR phenomenon caused by time delay, different noise terms and a weak periodic signal occurs in the vegetation growth model under different values of system parameters. With regard to the stationary state properties of the vegetation system, the results indicate that the terms of different noises and time delay can all accelerate the shift from the substantial state to the barren one of the ecological system, restrain the development of the vegetation system and weaken the stability of the ecological system. On the other hand, the additive noise strength always enhances the SNR and the SR phenomenon, while the intensity of multiplicative noise often reduces the effect of the SR. In particular, time delay can play different roles in exciting the SR phenomenon in different cases.

Continuum of floristic composition between two plant communities – Carici elongatae-Alnetum and Fraxino-Alnetum

Abstract One of the crucial debates in vegetation ecology is whether plant communities are discontinuous, distinguishable units or whether they change continuously. Phytosociology assumes discontinuity and its methodology requires subjective sampling during vegetation inventories. For that reason, some researchers argue that phytosociology artificially creates discontinuity among plant communities. Our aim was to assess the continuity between ash-alder riparian forest (Fraxino-Alnetum), and alder swamp forest (Carici elongatae-Alnetum), and to check whether discontinuity observed between these two plant associations is an effect of subjective sample plot choice. We conducted 57 phytosociological relevés within a regular grid covering potential sites of both plant communities. All relevés were arranged in order of decreasing relative cover of the diagnostic species for each plant association resulting in a gentle gradient, indicating a continuous transition from Fraxino-Alnetum to Carici elongatae-Alnetum. Similar results were obtained by detrended correspondence analysis. The proportion of species from the Querco-Fagetea class, typical to Fraxino-Alnetum, was decreasing with increasing proportion of species from the Alnetea glutinosae class, typical to Carici elongatae-Alnetum. This shift followed a gradient of ecological light-moisture indicator values. Our results confirmed continuous transition between two plant communities and led us to the conclusion that discontinuity resulted from the standard sampling protocol used in classical phytosociology. This protocol, however, is useful in searching for typological patterns, required for classification of plant communities, which is the main aim of phytosociology. Nevertheless, it does not provide full insight into the variability of vegetation and introduces uncertainty when trying to understand ecosystem dynamics. This uncertainty should be taken into account when phytosociological data are used for nature conservation recommendations and to draw conclusion about vegetation dynamics.

Cushion-plant protection determines guild-dependent plant strategies in high-elevation peatlands of the Cordillera Real, Bolivian Andes

The functional trait composition of plant communities reflects the influence of ecological constraints on their assembly. In high-elevation peatlands of the Andes, multiple abiotic and biotic stresses are exerted on herbaceous plant communities. We hypothesized that dominant cushion-plant species found in these ecosystems strongly influence the dynamics of their subordinate plants by providing protection against external stress. To test the hypothesis, we addressed the variation of functional traits reflecting how subordinate plants invest in durable tissues and develop below and above the canopy of two cushion-plant species dominating the ecosystem, with varying intensity of herbivore pressure. We expected different functional composition of plants living below (understory stratum) and above (emergent stratum) the canopy, related to cushion-plant protection. In addition, we considered the functional composition of basic morphological guilds, forbs and graminoids, as they invest differently in plant development and respond differently to herbivore pressure. We found contrasted functional compositions among morphological guilds and according to the position relatively to cushion-plant canopy. These variations support a protective influence of cushion-plants on subordinate plants for both strata, with investment into less costly leaves and a larger stature when protection is greater, depending on cushion-plant species and cushion-plant height. External stress mainly affected emergent plants and led to different responses according to the guild. Graminoids showed avoidant strategy, while forbs shifted from avoidant to tolerant strategy with increasing herbivore pressure. Both between-species and intraspecific trait variations contributed to explain functional changes of guilds, but the relative contributions depended on morphological guild and stratum. A basic trade-off in physiological and morphological variability determined different relative contribution in forbs and graminoids. While functional ecology classically focuses on the composition of spatially delimited communities, we here underline the need to address separately the functional composition and assembly dynamics of distinct guilds making a community. In addition, our survey is the first to investigate the functional ecology of high-elevation tropical peatlands and provides novel insights into vegetation ecology in this stressful ecosystem.

Vegetation ecology and carbon sequestration potential of shrubs in tropics of Chhattisgarh, India.

Tropical forests are well known to have great species diversity and contribute substantial share in terrestrial carbon (C) stocks worldwide. Shrubs are long-neglected life form in the forest ecosystem, playing many roles in the forest and human life. Shrub has great impact on vegetation attributes which in turn modify the C storage and capture. In the present investigation, an attempt has been made to explore the dynamics of shrub species in four fire regimes, viz. high, medium, low, and no fire zones of Bhoramdeo Wildlife Sanctuary of Kawardha forest division (Chhattisgarh), India. The variations in structure, diversity, biomass, productivity, and C sequestration potential in all the sites were quantified. The density and basal area of shrub varied from 1250 to 3750 individuals ha-1 and 2.79 to 4.92m2ha-1, respectively. The diversity indices showed that the value of Shannon index was highest in medium fire zone (3.77) followed by high, low, and no fire zones as 3.25, 3.12, and 2.32, respectively. The value of Simpson's index or concentration of dominance (Cd) ranged from 0.08 to 0.20, species richness from 0.56 to 1.58, equitability from 1.41 to 1.44, and beta diversity from 1.50 to 4.20, respectively. The total biomass and C storage ranged from 6.82 to 15.71 and from 2.93 to 6.76t ha-1, respectively. The shrub density, importance value index (IVI), and abundance to frequency ratio (A/F) significantly correlated between high fire and medium fire zone. The basal area was found to be significantly positively correlated between high fire and medium fire, and low and no fire zones, respectively. Two-way cluster analysis reflected various patterns of clustering due to influence of the forest fire which showed that some species have distant clustering while some have smaller cluster. Principal component analysis (PCA) reflects variable scenario with respect to shrub layer. Ventilago calyculata and Zizyphus rotundifolia showed higher correlation between themselves in terms of basal area (BA). The total shrub production was 1.59-3.53tha-1year-1 while the C sequestration potential of 0.71-1.57tha-1year-1 under different fire regimes. Shrub community in the medium fire zone reflected higher productivity and higher C sequestration in comparison to other fire zone. Among the different plant parts, the biomass accumulation ratio was highest in the root of shrub community among various fire regimes. Screening of species for restoration and different land-use pattern on the basis of biomass accumulation and carbon sequestering potential would be an effective strategy for decision-making in sustainable forest management.

Phytosociology and ecology of treeline ecotone vegetation in Rolwaling Himal, Nepal

Questions: Species composition and ecology of treeline vegetation types in the Rolwaling Valley is largely unknown to date. The aim of this study is to differentiate plant communities along the elevational gradient in the treeline ecotone, and to identify site factors which cause the differentiation of the treeline ecotone vegetation. Study area: Rolwaling Valley (27 degrees 52' N;86 degrees 25' E) in the central Himalaya, Nepal. Methods: We included 91 phytosociological releves along three elevational transects in this analysis, ranging from 3745 to 4300 m a.s.l. Plant communities were differentiated and vegetation-environment relationships analysed using cluster analysis and ordination. For each community and higher ranked unit, we detected diagnostic species according to their fidelity index (phi coefficient). Ecological preferences of each community were examined using one-way analysis of variance (ANOVA). Results and conclusions: We identified five communities, belonging to two different classes: the Synotis alata-Abies spectabilis and Ribes glaciale-Abies spectabilis communities occupy the upper part of the subalpine forest zone, representing the uppermost forest stands below treeline. These communities are primarily comprised of Abies spectabilis and Betula utilis in the tree layer, with varying cover of several tree species and distinct differences within the herb layer. Above treeline, the mixed forest stands are replaced by the species-poor Boschniakia himalaica-Rhododendron campanulatum community, forming a dense krummholz belt. We assigned the forest and krummholz communities to the class Betula utilis-Abies spectabilis forests. In the alpine zone two communities were classified and assigned to the class Dasiphora arbuscula-Rhododendron anthopogon dwarf shrub heaths.The species-poor Pedicularis cf. micro calyx-Rho dodendron anthopogon community has a less developed herbaceous layer, whereas the Anaphalis royleana-Rhododendron anthopogon community is characterized by higher cover and higher species richness of herbs and grasses. Species composition of identified communities is mainly differentiated by soil temperature, nitrogen supply and availability, and soil moisture content.

Phytosociology and ecology of treeline ecotone vegetation in Rolwaling Himal, Nepal

Phytosociology and ecology of treeline ecotone vegetation in Rolwaling Himal, Nepal

Insights on Forest Structure and Composition from Long-Term Research in the Luquillo Mountains

The science of ecology fundamentally aims to understand species and their relation to the environment. At sites where hurricane disturbance is part of the environmental context, permanent forest plots are critical to understand ecological vegetation dynamics through time. An overview of forest structure and species composition from two of the longest continuously measured tropical forest plots is presented. Long-term measurements, 72 years at the leeward site, and 25 years at windward site, of stem density are similar to initial and pre-hurricane values at both sites. For 10 years post-hurricane Hugo (1989), stem density increased at both sites. Following that increase period, stem density has remained at 1400 to 1600 stems/ha in the leeward site, and at 1200 stems/ha in the windward site. The forests had similar basal area values before hurricane Hugo in 1989, but these sites are following different patterns of basal area accumulation. The leeward forest site continues to accumulate and increase basal area with each successive measurement, currently above 50 m2/ha. The windward forest site maintains its basal area values close to an asymptote of 35 m2/ha. Currently, the most abundant species at both sites is the sierra palm. Ordinations to explore variation in tree species composition through time present the leeward site with a trajectory of directional change, while at the windward site, the composition of species seems to be converging to pre-hurricane conditions. The observed differences in forest structure and composition from sites differently affected by hurricane disturbance provide insight into how particular forest characteristics respond at shorter or longer time scales in relation to previous site conditions and intensity of disturbance effects.

Herbaceous species diversity and soil attributes along a forest-savanna-grassland continuum in a dry tropical region

Dry tropical vegetation is under major pressure of degradation due to various anthropogenic interferences and is characterized by the patches of forest, savanna and grassland systems. These adjacent systems may represent a gradient of various ecological attributes which can be better understood by studying these in a continuum approach to recognise changes at grassroots level. The herbaceous vegetation, a dynamic layer of an ecosystem, acts as an indicator of the environmental changes. The present study is designed to assess the herbaceous plant diversity and soil attributes along the dry deciduous forest-savanna-grassland continuum. A total of nine sites equally distributed in forest, savanna and grassland systems of Vindhyan region were selected. Soil moisture, water holding capacity, carbon, nitrogen, phosphorus and species richness, evenness, diversity and plant biomass were measured at each site. The results showed significant changes in soil attributes and herbaceous species composition, diversity and biomass along the continuum. Forest exhibited higher soil moisture, carbon and nitrogen contents than the savanna and grassland, while the herbaceous species diversity and biomass were higher in grassland vegetation. Savanna revealed intermediate levels of soil water availability, soil nutrients, community composition and species diversity of the herbs. The results showed that the herbaceous diversity was maximum in the grassland followed by savanna and forest. Moreover, a change in community composition and plant functional attributes was also observed. Evolvulus nummularius-Justicia simplex, Justicia simplex-Evolvulus nummularius and Cynodon dactylon-Cyperus compressus communities characterised the forest, savanna and grassland vegetation, respectively. Fabaceae was the most dominant family having the highest number of species in grassland followed by savanna and forest vegetation. Correlation analysis revealed a significant interaction between soil water and nutrient availability with vegetation parameters. Overall, heterogeneity of soil attributes maintaining the community structure and species diversity are essential components for understanding the ecology of herbaceous vegetation in dry tropical ecosystems. The findings of this study may contribute to the holistic understanding and development of ecological management tools for such a continuum.