Abundance Of Plant Functional Types Research Articles

European Atlantic deciduous forests are more resilient to fires than Pinus and Eucalyptus plantations

In this study, we assess how ecosystem type affects the short-term post-fire resilience of fire-prone forests, which are the predominant ecosystems in South West (SW) Europe. For this purpose, we focused on three forest systems, widespread across the European Atlantic coast, which are highly susceptible to fires at their SW distribution boundary, namely the European thermophilous Atlantic deciduous forests, dominated by Quercus robur L., and two types of forest plantations widespread globally, Eucalyptus globulus Labill. and Pinus pinaster Aiton plantations. At the community structure level, resilience to fire was measured based on changes in cover of each vertical stratum. At the functional level, resilience to fire was measured based on replacements of (both morphological and regenerative) plant functional types in the overstory and understory layers. The study variables were vertical structure and abundance of plant functional types in both overstory and understory layers. Vertical structure was assessed by defining nine vertical strata and estimating the cover in each vegetation stratum. All species identified in the overstory and understory layers were functionally classified according to their morphological attributes and regenerative traits pertaining to fire. One year after fire, we observed considerable differences in the structure between the three forest communities studied, particularly in the overstory layer, because most of the vertical strata were well recovered in the oak forest, partially recovered in the E. globulus plantation, and completely lost in the P. pinaster plantation. In contrast to the Atlantic deciduous forest and eucalyptus plantation, the pine plantation displayed distinct changes in its distribution of plant functional types. The pine plantation showed extremely low resilience to fire because the overstory layer decreased considerably, and the understory layer experienced substantial changes in the distribution of morphological and regenerative plant functional types. Fire favoured certain species which prevailed over others and, while grasses, herbaceous and spiny shrubs increased, the abundance of most morphologically functional plant types disappeared or decreased. These changes in the structure of forest communities and in the distribution of plant functional types have important implications for ecosystem functioning and services provision. Therefore, this study may serve as a foundation for devising forest management measures aimed at increasing ecosystem resilience to fire.

Simulation of Multi-Species Plant Communities in Perturbed and Nutrient-Limited Grasslands: Development of the Growth Model ModVege

Simulating the dynamics of plant species or types in grassland communities remains an open area of research for which the Community Simulation Model (CoSMo) offers novel approaches. The grassland model ModVege was first parameterised based on a functional vegetation typology, in which types “A” and “B” include fast-growing grass species with a phenology-dependent nutrient-capture strategy inherent to fertile grasslands, while the nutrient conservation strategy and late flowering characterise the other types as “b”. ModVege was then coupled to the CoSMo rule set to dynamically simulate the relative abundance of plant functional types or individual species, assessed across fertilised and unfertilised, abandoned and mown conditions in a grassland site of the Massif Central of France. While for the simulation of aboveground biomass, model performance is not unambiguously linked to explicit consideration of plant diversity, the simulation of relative abundance for the whole community is satisfactory (relative root mean square error of ~13–25% when simulating functional types and ~28–52% when simulating species). This study extends previous studies by coupling CoSMo, for the first time, to a grassland-specific model and applying it to conditions (long-term observations, extended number of plant species, absence of fertilisation, frequent mowing and abandonment) never investigated before.

Time-series maps reveal widespread change in plant functional type cover across Arctic and boreal Alaska and Yukon

Widespread changes in the distribution and abundance of plant functional types (PFTs) are occurring in Arctic and boreal ecosystems due to the intensification of disturbances, such as fire, and climate-driven vegetation dynamics, such as tundra shrub expansion. To understand how these changes affect boreal and tundra ecosystems, we need to first quantify change for multiple PFTs across recent years. While landscape patches are generally composed of a mixture of PFTs, most previous moderate resolution (30 m) remote sensing analyses have mapped vegetation distribution and change within land cover categories that are based on the dominant PFT; or else the continuous distribution of one or a few PFTs, but for a single point in time. Here we map a 35 year time-series (1985–2020) of top cover (TC) for seven PFTs across a 1.77 × 106 km2 study area in northern and central Alaska and northwestern Canada. We improve on previous methods of detecting vegetation change by modeling TC, a continuous measure of plant abundance. The PFTs collectively include all vascular plants within the study area as well as light macrolichens, a nonvascular class of high importance to caribou management. We identified net increases in deciduous shrubs (66 × 103 km2), evergreen shrubs (20 × 103 km2), broadleaf trees (17 × 103 km2), and conifer trees (16 × 103 km2), and net decreases in graminoids (−40 × 103 km2) and light macrolichens (−13 × 103 km2) over the full map area, with similar patterns across Arctic, oroarctic, and boreal bioclimatic zones. Model performance was assessed using spatially blocked, nested five-fold cross-validation with overall root mean square errors ranging from 8.3% to 19.0%. Most net change occurred as succession or plant expansion within areas undisturbed by recent fire, though PFT TC change also clearly resulted from fire disturbance. These maps have important applications for assessment of surface energy budgets, permafrost changes, nutrient cycling, and wildlife management and movement analysis.

Initial understory vegetation responses following different forest management intensities in Illyrian beech forests

AbstractBackground and questionsHow forest vegetation responds to disturbance continues to be a focal point, especially in the context of biodiversity conservation. To investigate the short‐term effects of forest management on understory vegetation, we asked: (a) Are there any plant indicator species associated with different felling intensities? (b) What are the differences in abundance of plant functional types along the disturbance gradient? (c) How do typical forest species respond to silvicultural treatments?LocationDinaric Mountains, Slovenia.MethodsAt each of three study sites in Illyrian beech forests, nine plots (4,000 m2) were established, comprising a total of 27 plots. Three different felling intensities were implemented at each site, with one third of the plots assigned to each treatment: control, 50% of the growing stock removed and 100% of the growing stock removed. In the centre of each plot, a vegetation survey of vascular plants was done before (in 2012) and two years after (in 2014) felling in a circular sampling area of 400 m2. We employed indicator species analysis, and species were grouped into functional types with respect to their traits.ResultsUnderstory species composition differed significantly between treatments. Forty‐seven species (out of 251) were significantly associated with the 100% felling intensity. This relatively high number of indicators was due to the post‐disturbance colonization of early‐successional, non‐forest species, coupled with the expansion of pre‐treatment resident species. Only one species was a strong indicator for the 50% felled plots, while three species showed a preference for the unfelled plots. Graminoids, tall perennial forbs, annual/biennial forbs and legumes exhibited the most prominent increase in cover at the 50% and 100% felling intensity. Ferns showed non‐significant changes, whereas woody plants exhibited a decrease in the most intensive treatment. In general, most of the typical forest species responded with increased frequency and/or abundance after felling.ConclusionsThe post‐treatment taxonomic and functional composition of plant communities exhibited the largest changes in the most intensively felled stands. Overall, in the short term, ecological conditions in canopy gaps were not modified to an extent that would be detrimental to the persistence of typical forest species.

Continuous picking may increase bilberry yields

Accumulated knowledge about the health benefits of bilberry ( L.) has increased the demand and utilization of wild bilberries. Intensive berry picking by metal rakes is believed to cause damage in bilberry stands in areas under continuous picking pressure, and hence expected to hamper the production of berries in forthcoming years. We conducted an experiment to examine the effect of continuous bilberry picking by metal rake on the number of bilberry flowers and fruits, fruit mass, compensation for biomass loss after picking, and plant functional type abundance in the understorey in northern Finland. Bilberry lost less than 0.5% of its biomass annually during the three-year study period due to rake harvesting. The number of flowers was not significantly affected by damage caused by picking, while both fruit production and fruit set increased without any indication of reduced fruit mass, and biomass loss was fully compensated. Moreover, the relative abundance of plant functional types was not affected by picking during the study. We suggest that the low intensity and timing of damage act as a buffer against the adverse effects of picking on bilberry fruit production. On the basis of this study, it is reasonable to anticipate that there are no indications that current intensive berry picking would not be on a sustainable level.Vaccinium myrtillus

Forty years of vegetation change in former coppice‐with‐standards woodlands as a result of management change and N deposition

AbstractQuestionDid vegetation of former coppice‐with‐standards woodlands, which were in conversion towards high forest for about 100 yrs, change over the last 41 yrs (1970–2011)? What were the main drivers of vegetation change?LocationDransfeld Plateau, central Germany.MethodsRepetition of 85 historical semi‐permanent vegetation plots located in 13 forest patches on limestone soil. Differences in species composition and plant functional types between historical and recent plots were analysed using a block multi‐response permutation procedure (bMRPP), NMDS, indicator species analysis (ISA) and ANOVA.ResultsWe found significant changes in all vegetation layers. In the tree layer, Fagus sylvatica and Hedera helix had increased, while Quercus robur and Carpinus betulus had decreased. In the understorey, tree regeneration had strongly increased. In the herbaceous layer, species richness had decreased from 30 to 24 species per 100 m², and the abundance of plant functional types had changed: the proportion of geophytes and therophytes had increased, while the proportion of hemicryptophytes had decreased. Spring‐green species (i.e. species active mainly before tree foliation) had increased, while summer‐green species had decreased. In addition, the estimated mean SLA of herbaceous species had increased. The proportion of closed‐forest species had slightly increased, while the proportion of species of forest edges and clearings had decreased. NMDS ordination separated the herbaceous layers from 1970 and 2011 along the second axis, which correlated with the indicator values for continentality (decrease over time) and N (increase over time).ConclusionsAlthough the stands still shared many characteristics of coppice‐with‐standards woodlands, the vegetation had clearly shifted towards that of darker and more nutrient‐rich forest. This indicates both a marked legacy of historic coppice management and a strong influence of recent high forest management, as well as N deposition.

Empirical Modelling of Vegetation Abundance from Airborne Hyperspectral Data for Upland Peatland Restoration Monitoring

Peatlands are important terrestrial carbon stores. Restoration of degraded peatlands to restore ecosystem services is a major area of conservation effort. Monitoring is crucial to judge the success of this restoration. Remote sensing is a potential tool to provide landscape-scale information on the habitat condition. Using an empirical modelling approach, this paper aims to use airborne hyperspectral image data with ground vegetation survey data to model vegetation abundance for a degraded upland blanket bog in the United Kingdom (UK), which is undergoing restoration. A predictive model for vegetation abundance of Plant Functional Types (PFT) was produced using a Partial Least Squares Regression (PLSR) and applied to the whole restoration site. A sensitivity test on the relationships between spectral data and vegetation abundance at PFT and single species level confirmed that PFT was the correct scale for analysis. The PLSR modelling allows selection of variables based upon the weighted regression coefficient of the individual spectral bands, showing which bands have the most influence on the model. These results suggest that the SWIR has less value for monitoring peatland vegetation from hyperspectral images than initially predicted. RMSE values for the validation data range between 10% and 16% cover, indicating that the models can be used as an operational tool, considering the subjective nature of existing vegetation survey results. These predicted coverage images are the first quantitative landscape scale monitoring results to be produced for the site. High resolution hyperspectral mapping of PFTs has the potential to assess recovery of peatland systems at landscape scale for the first time.

Plant community changes as ecological indicator of seabird colonies’ impacts on Mediterranean Islands

The aim of this study is to investigate vegetation changes on small Mediterranean islands under the impact of the drastic expansion of the gull colony, at local scale over eleven years using a set of permanent plots. First, we focused on functional aspects of vegetation in addition to its specific composition with regard to the plant functional types (Raunkiaer growth forms and Grime life strategies) as indicators of vegetation changes. Second, we used STATICO analysis to investigate patterns of change in the relationship between environmental variables and floristic composition. Third, we quantified the changes in the abundance of plant functional types by applying a simple comparison test between the two observation dates. Fourth, we investigated the relationship between vegetation changes (species turnover, plant functional type dynamics, and species richness) and gull density by performing simple linear regression. Our results show that gull density did not evolve equally for all plots. For areas where gull density increased, we recorded ruderalization of the vegetation. Surprisingly, in areas where there was a decrease in gull density, no clear pattern of vegetation change was apparent. We observed a statistically significant increase in the number of plant species due only to the increase in ruderal and stress ruderal and geophyte species. Gull colonies were responsible for high species turnover between 1997 and 2008. The higher the density of gulls, the lower the species number in 1997 and 2008. For high gull nest densities, we observed a high proportion of ruderal plant species and a low proportion of stress tolerant species. Gulls induced an increase of stress-ruderal species. We show that nest density recorded in 1997 is mainly responsible for the changes in vegetation composition, species turnover and proportions of plant functional types. We noted that a decrease in gull nest density does not necessarily induce a return to previous vegetation composition patterns. This may be seen as evidence of the inertial nature of the changes in island vegetation in the face of strong changes in environmental conditions such as the recent drastic expansion of gull colonies. Garbage management policy can have a strong and long-term impact on remote ecosystems.

Changes in vegetation structure induced by domestic grazing in Patagonia (Southern Argentina)

We analyzed the structural differences associated with grazing exclusion on vegetation by studying 24 grazed–ungrazed paired sites in Patagonia (Argentina). Our objectives were to evaluate the effect of grazing on plant species composition, plant diversity, the relative abundance of plant functional types, and the vertical and horizontal structure of the plant community. This study across the shrub-grass steppes of Patagonia highlights some important characteristics of the vegetation response to a major disturbance factor we show that shrub encroachment is not a generalized response of the steppe to grazing. Grazed areas presented lower richness and diversity than exclosures. Physiognomic changes (as describe by relative abundance of plant functional types) were less important than those observed at the species level. These results shown that the status of the shrub-grass steppes of the Occidental district of Patagonia can not be characterized in terms of contrasting physiognomic states as in the case of the grass steppes of the Subandean district. Forbs and a few mesophytic and xerophytic grasses are the key elements to identify the condition of the steppe. Monitoring programs should focus on the relative abundance of these components.

Responses of plant functional types to environmental gradients in the south-west Ethiopian highlands

Abstract:Plant functional types across environmental gradients can be considered as a powerful proxy that reveals vegetation–environment relationships. The objectives of this study were to investigate the response in the relative abundance of plant functional types along altitudinal gradients and to examine the relationship of plant functional types to environmental variables. The study was conducted in the Gughe-Amaro Mountains, in the south-west Ethiopian highlands. We established 74 plots with an area of 400 m2(20 × 20 m) each along altitudinal ranges between 1000 and 3000 m asl. Data on site environmental conditions and on the abundance of plant functional types were analysed using the constrained linear ordination technique (RDA) in order to identify the relationships between plant functional types and environmental variables. Altitude, soil organic carbon, soil sand fraction and surface stone cover were significantly related to the relative abundance of plant functional types across the gradient. Tussocks and thorns/spines were abundant in lower altitudinal ranges in response to herbivory and drought while rhizomes and rosettes were abundant at higher altitudes in response to the cold. Generally our results show that topographic attributes (altitude and slope) as well as soil organic carbon play an important role in differentiating the relative abundance of plant functional types in the investigated gradient. Thus, considering specific plant functional types would provide a better understanding of the ecological patterns of vegetation and their response to environmental gradients in tropical regions of Africa prone to drought.

Long-term dynamics of water and carbon in semi-arid ecosystems: a gradient analysis in the Patagonian steppe

We used a soil water simulation model and remotely sensed data to study the long-term dynamics of transpiration, evaporation, drainage and net primary production across a precipitation gradient in Northwestern Patagonia (Argentina). The proportion of precipitation transpired, the precipitation use efficiency and the transpiration use efficiency were constant across the gradient that covered a range of 150 to 600 mm. The proportion of water evaporated was higher than the proportion drained at the driest extreme of the gradient. The opposite relationship was observed at the wet extreme. Two important characteristics of arid-semiarid systems dominated by winter precipitation emerged from our analyses: the importance of drainage losses and the asynchrony between evaporation and transpiration fluxes. These characteristics of the water dynamics influence the relative abundance of plant functional types and are crucial to generate heterogeneity at the landscape level. The coefficient of variation (CV) of transpiration, evaporation and ANPP was, in general, lower than the CV of annual precipitation. This pattern suggests a buffering capacity of the ecosystem. The ecosystem would be able to damp at the functional level inter-annual changes in the availability of resources.

Relative Abundance of Plant Functional Types in Grasslands and Shrublands of North America

We analyzed the geographic distribution and climatic controls of the distribution of plant functional types (PFT) in temperate grasslands and shrublands of North America. It has been widely accepted that temperature is the principal control on the distribution of C3 and C4 species. Our results show that precipitation and its seasonal distribution are also important. C4 grass distribution was positively related to three climatic variables: mean annual precipitation, mean annual temperature, and the proportion of the precipitation falling in summer. These variables accounted for 66% of the total variability of this functional type. C3 grass abundance decreased with mean annual temperature and increased with the proportion of the precipitation falling during winter (r2 = 0.37). Sixty‐two percent of the variability in the relative abundance of shrubs was explained by mean annual precipitation and the proportion of winter precipitation. Latitude and longitude explained a substantial portion of the variability of the distribution of the relative abundance of shrubs, C3 grasses, and C4 grasses (53, 46, and 61%, respectively). Along a given longitude, C3 grasses increased with latitude. As one moves westward, C4 grasses are replaced by shrubs. The relative abundance of C4 grasses reached a maximum at southern latitudes and eastern longitudes. Succulents showed a marginal decreasing trend with latitude. No relationship with geographic variables was detected for forbs.