Vegetation Releves Research Articles

Effect of climate change on fir forest communities in the mountains of South-central Greece

The endemic oro-Mediterranean fir (Abies spp.) forests in Greece are valuable ecosystems with high ecological and economic importance. In the mountains in south-central Greece, the availability of moisture plays a crucial role in the floristic composition, structure and distribution of fir forest communities. Because of the predicted adverse climate changes for the Mediterranean zone, suitability of many habitats for the growth of fir forests will change. This study aims to quantify the degree to which these forests will be affected by climate change. Current and future climatic conditions in the area studied were estimated for two periods of time (2041 – 60, 2061 – 80) and two climate change scenarios (RCP 4.5, RCP 8.5). Vegetation releves were classified and ordinated. Recursive partitioning was used to reveal the most important factor for discriminating the main plant communities and determining the ecological threshold between them. Current and future suitability of bioclimatic space for fir forest communities was identified. The effect of climate change was assessed based on predicted changes in the potential distribution, in terms of size and location, of fir forest communities. Two plant communities that reflect the differentiation of fir forests into xerophytic and mesophytic forest types are described. Among several climatic variables, spring drought was the best factor discriminating these two forest communities. The quantification of the threshold for drought in these two plant communities was used to predict their potential distribution in the area studied. Potential distribution of fir forests in south-central Greece will change in the future, due to a reduction in suitable bioclimatic space and shift to higher altitudes. The effect is expected to be greater for xerophytic forest communities, especially in the worst-case scenario (RCP 8.5) and in 2061–80.

Phytosociology of Atractylis cancellata and Micromeria microphylla communities in southern Italy with insights on the xerothermic steno-Mediterranean grasslands high-rank syntaxa

In the present paper a phytosociological study on the dry grassland communities identified in the western sector of the Murgia Plateau (Murgia delle Gravine) and in the Lucanian badlands territory is presented. Forty vegetation releves were carried out using the Braun-Blanquet phytosociological approach. Two new associations characterized by a therophytic dominance, namely Lysimachio foeminae-Atractylidetum cancellatae and Campanulo erini-Micromerietum microphyllae, are described and discussed from a syntaxonomic and biogeographic viewpoint. In addition, new phytosociological data concerning the Petrosedum ochroleucum communities developed on limestone outcrops, the perennial Hyparrhenia hirta steppe-like grasslands of the low-altitude areas of the Murgia hills and the small-size Brachypodium distachyum therophytic communities are presented.

Describing vegetation at the landscape level: “PAYSAGE”, a database designed for series and geoseries datasets

The CarHAB project, funded by the French Ministry of Environment, was set up to map the vegetation all over the French territory. In this objective, both analytical (plot) releves and synreleves were carried out. Based on the case study of low mountain habitats in the “chaine des Puys” (Massif central, France), this paper presents i) the methodology developed to carry out vegetation releves at the landscape scale and ii) the database designed to store and fit synreleves, as part of the national VegFrance database. This paper presents the structure of the “Paysage” database, the metadata collected together with plants communities in the synreleves (and geosynreleves), the method to record the synreleves and how they are managed for the mapping of series and geoseries. The interpretation of the dataset regarding anthropic pressure on this landscape will be suggested. © 2019, Babes-Bolyai University, "Alexandru Borza" Botanic Garden. All rights reserved.

Liming in spruce stands: What effect does the number of lime applications have on the herb layer?

Forest liming is often used as a mitigation tool to counteract soil acidification that is caused by atmospheric deposition. However, our understanding of the long-term effects of liming on forest communities is still incomplete. We examine the effects of repeated liming on the herb layer of spruce stands in the Ore Mountains in East Germany. The area is characterised by acidic bedrock and profound soil acidification caused by high levels of anthropogenic sulphur deposition in the late twentieth century. Lime has been applied as part of forest management since 1988. We created a stratified sample in which we recorded vegetation releves covering spruce stands without liming (L0) and with one to five lime applications (L1–L5). We found a positive correlation between liming intensity and alpha diversity. Most of the indicator species were identified for spruce stands with high liming intensity (L2–L5), but no indicators were found for unlimed stands. From the third liming, the impact of lime application on species diversity and composition saturated. Several of the species promoted by liming are typical for mature stands of the natural vegetation but had declined in the twentieth century. Thus, a slight trend towards the restoration of the natural vegetation can be seen after liming. However, this is contrasted with a strong increase in species that are disturbance indicators (i.e. species of nitrogen-rich soils and open habitats). Continuation of liming as part of regular forestry management will cause these effects to establish permanently over large areas. Based on these findings, we make suggestions to adapt forest management strategies.

Fire increases the reproduction of the dominant grass Brachypodium retusum and Mediterranean steppe diversity in a combined burning and grazing experiment

AbstractAimsWe assessed what the effects of fire and grazing are on vegetative growth and sexual reproduction of Brachypodium retusum, the dominant species of Mediterranean Thero‐Brachypodietea grasslands (“steppes”) and on species composition of the associated plant community.Location“La Crau”, southeastern France.MethodsWe set up a split‐plot experiment testing the effects of fire season (winter, summer) and grazing on plant cover, inflorescence number, seed set and germination of Brachypodium retusum in traditionally grazed grasslands. We further analyzed plant species composition and diversity in vegetation relevés. The same fire treatments were tested in a second experiment in long‐term grazing exclosures.ResultsBrachypodium retusum showed a rapid post‐fire recovery, but other species of the associated plant community, in particular annuals, recovered as fast or even faster. Fire increased Brachypodium retusum inflorescence production and seed set per inflorescence and this effect was stronger in the summer fire treatment. At the community level, fire significantly increased species richness, evenness and Bray–Curtis dissimilarity in the second post‐fire season and again, the summer fire effect was stronger. Grazing exclusion for two seasons had only a small effect on Brachypodium retusum and the associated plant community. The effect of both fire treatments on Brachypodium retusum was similar in long‐term exclosures. In these exclosures, fire resulted in a community shift towards the species composition of traditionally grazed steppes.ConclusionsThe concomitant positive effects of experimental burning on Brachypodium retusum reproduction and on plant diversity of Mediterranean steppe vegetation suggest that the system is adapted to fire as an important driver of community composition. Annual species surviving as seeds are as successful in post‐fire recovery as perennial resprouters. Prescribed burning may be an alternative strategy to restore community structure in abandoned (ungrazed) steppes showing a decline in typical grassland species after several years of grazing abandonment.

Exploiting low-cost and commonly shared aerial photographs and LiDAR data for detailed vegetation structure mapping of the Wadden Sea island of Ameland

Regular mapping of vegetation structure is important for biodiversity monitoring, and increasingly for tracking compliance with nature policy mandates. As such, the Netherlands uses vegetation structure mapping to monitor the Natura 2000 site on the Dutch Wadden Sea island of Ameland. Three decades of natural gas extraction here has caused soil subsidence, impacting vegetation and habitats on the island. In the Netherlands, vegetation structure mapping is typically done using conventional techniques, primarily field surveys combined with visual interpretation of aerial photographs. This procedure is time-consuming and often too inconsistent and inefficient for large areas. In the current study we exploited commonly shared and low-cost aerial photographs and LiDAR data for detailed vegetation structure mapping. Aerial photographs are not always easy to use in automatic classification procedures, as they often lack calibrated spectral reflectance values. Furthermore, pre-processing of aerial photographs to render them more attractive may skew the image so that it no longer accurately depicts the original scene anymore. Our aim was to determine if automatic or semi-automatic classification techniques could be applied to these readily available Dutch data to support mapping and monitoring of the vegetation structure of larger areas. We compared the effectiveness of two well-known classification methods, namely rule-based (RB) and random forest (RF). The RF algorithm was applied with its default settings, as supplied by eCognition software. Both classification methods performed well, with overall accuracies of 84.1% (RB) and 86.4% (RF). Each method, however, has its advantages and disadvantages, which are discussed. Overall, RF classification was preferred over RB classification, as it was better able to handle the complexity of the rules needed for distinguishing more classes. Provision of in situ training data, such as vegetation releves, was not really problem in the Dutch context. Nevertheless, exploitation of new digital aerial photographs produced each year in a semi-automatic process remains a challenge. Commercial high resolution satellite imagery (~0.5 m resolution) is therefore still preferred by us. This latter, unfortunately, is more costly than aerial photographs which, while not always ideal, are readily available at no additional costs for involved organisations

TwoCladoniaSpecies New to Italy from Dry Habitats in the Po Plain

Gheza, G., Nascimbene, J., Mayrhofer, H., Barcella, M. & Assini, S. 2018. Two Cladonia species new to Italy from dry habitats in the Po Plain. - Herzogia 31: 293–303.Cladonia conista and C. pulvinata occur at several sites in dry lowland habitats in the Po Plain (northern Italy). Vegetation releves are provided in order to characterize the main lichen associations (Cladonietum rei, Cladonietum foliaceae, Pycnothelio-Cladonietum cervicornis) and vascular plant communities in which the two species were found in Thero-Airion dry acidic grasslands and in dry open Calluna heathlands.

Plant diversity and composition of rice field bunds in Southeast Asia

Which plant species can be found on rice field bunds and what are the prevailing life forms? Which plant communities occur and what are the main environmental drivers and phytogeographic patterns shaping these communities? How do species diversity and composition differ between bunds and paddies? To answer these questions, 133 vegetation releves using the Braun-Blanquet method were collected in lowlands and uplands of Vietnam and the Philippines between 2012 and 2015. Soil samples were collected and farmers were interviewed. Properties of soil, climate, and geography were assessed, further structural parameters, landscape heterogeneity, seasonality, management and intensity of cultivation. Hierarchical UPGMA cluster analysis and NMDS ordinations were performed to visualize variation in plant community composition and the determinants. We found 302 vascular plant species, of which 94 species are red listed by the IUCN (under category “Least concern”). Therophytes and helophytes are the prevailing life forms. Six clusters of plant communities were classified, and temperature, soil acidity, land use intensity and nutrient availability were identified (according to relevance) as explanatory variables. Bunds revealed higher species richness than paddies and bunds in mountain areas were more species-rich than those in the lowlands. We conclude that the composition of bund communities provides valuable information on environmental and biogeographical conditions of the local rice landscapes, and that it is probably the best applicable and most reliable indicator of management intensity.

Alien species in different habitat types of Slovenia: analysis of vegetation database

Background and purpose: Invasion by alien plant species is considered as one of major threats to biodiversity. Actual invasion of different habitats in particular country is important for understanding processes that are important in invasion ecology as well as for the nature conservation. Materials and methods: Vegetation releves stored in a database Vegetation of Slovenia were translated into 30 EUNIS habitat types which enables comparison with similar studies in other European countries. Out of the 18 606 plots stored in the database stratified resampling yielded 6 517 releves. For each vegetation plot we calculated mean relative species richness per plot and total cover of archeophytes, neophytes and native species. Results: Most invaded habitat type with the highest species percentages of alien species (archaeophytes and neophytes) is arable land (I1). In addition, archaeophytes occur in higher percentages in trampled areas, anthropogenic herb stands, mesic grasslands, and moist tall-herb stands. Neophytes are on the other hand highly represented in arable land, trampled areas, but also riverine scrubs and wet and moist tall-herb stands. Conclusions: Pattern across different regions in Europe is very similar with anthropogenous habitats being the most invaded by alien species.

Vegetation-based bioindication of humus forms in coniferous mountain forests

Humus forms, especially the occurrence and the thickness of the horizon of humified residues (OH), provide valuable information on site conditions. In mountain forest soils, humus forms show a high spatial variability and data on their spatial patterns is often scarce. Our aim was to test the applicability of various vegetation features as proxy for OH thickness. Subalpine coniferous forests dominated by Picea abies (L.) H. Karst. and Larix decidua Mill. were studied in the Province of Trento, Italian Alps, between ca. 900 and 2200 m a.s.l. Braun-Blanquet vegetation releves and OH thickness were recorded at 152 plots. The vegetation parameters, tested for their suitability as indicators of OH thickness, encompassed mean Landolt indicator values of the herb layer (both unweighted and cover-weighted means) as well as parameters of vegetation structure (cover values of plant species groups) calculated from the releves. To our knowledge, the predictive power of Landolt indicator values (LIVs) for humus forms had not been tested before. Correlations between OH thickness and mean LIVs were strongest for the soil reaction value, but indicator values for humus, nutrients, temperature and light were also significantly correlated with OH thickness. Generally, weighting with species cover reduced the indicator quality of mean LIVs for OH thickness. The strongest relationships between OH thickness and vegetation structure existed in the following indicators: the cover of forbs (excluding graminoids and ferns) and the cover of Ericaceae in the herb layer. Regression models predicting OH thickness based on vegetation structure had almost as much predictive power as models based on LIVs. We conclude that LIVs analysis can produce fairly reliable information regarding the thickness of the OH horizon and, thus, the humus form. If no releve data are readily available, a field estimation of the cover values of certain easily distinguishable herb layer species groups is much faster than a vegetation survey with consecutive indicator value analysis, and might be a feasible way of quickly indicating the humus form.

Human disturbance, habitat degradation and niche shift: the case of the endemic Calendula maritima Guss. (W Sicily, Italy)

Calendula maritima Guss. is a plant endemic to the coastline of W Sicily, whose distribution range experienced a dramatic shrinkage during the last centuries along with the degradation and fragmentation of the associated plant assemblages. According to that, it can represent an effective target species to test the response of coastal biota to anthropogenic disturbance. In order to better understand the niche width of C. maritima, the coastal plant communities in which it is still found have been investigated through vegetation releves carried out on different size plots. Although the sea marigold has been considered as a pioneer species typical of shifting dunes, field investigations highlighted that it also occurs in different plant assemblages. Data concerning the smaller plots allowed the identification of three groups of releves: one showing the highest number of trivial ruderal plants, another hosting some psammophilous species, and a third linked with rocky surfaces. These three groups do not cluster with the releves issuing from literature, carried out some 40 years ago, that mostly focused on dune ecosystems. It is assumed that the strong floristic differences between these two different types of releves may be linked with the destruction of shifting dunes occurred over the last decades, and which also caused the local extinction of many other plants related with this habitat. However, this could also reflect a lack of historical releves concerning C. maritima populations growing on coastal rocky sites. Interestingly, a gradual expansion of the niche of C. maritima was highlighted, likely depending on the ability of the species to colonize new plant communities in response to increasing anthropogenic disturbance. Our results also confirm that hybridization with the contiguous congener species Calendula fulgida Raf. may represent a major threat for conservation of the remnant populations of C. maritima.

Development of Soil Characteristics and Plant Communities On Reclaimed and Unreclaimed Spoil Heaps After Coal Mining

The aim of this study was to compare soil characteristics, plant communities and the rate of selected ecosystem function performance on reclaimed and unreclaimed plots (left for spontaneous succession) of different age on spoil heaps. Twelve spoil heaps (three circle plots of radius 12.5 m) near the town Kladno in north-west direction from Prague, created after deep coal mining, were compared. Five mixed soil samples from organo-mineral horizons in each plot were analysed for total content of carbon, nitrogen and phosphorus. In addition, active soil pH (pHH2O) was determined. Plant diversity was determined by vegetation releves. The biodiversity value of the habitat according to the Habitat Valuation Method was assessed and the rate of evapotranspiration function by the Method of Valuation Functions and Services of Ecosystems in the Czech Republic were determined. The higher organo-mineral layers and higher amount of total nitrogen content were found on the older reclaimed and unreclaimed plots than in younger plots. The number of plant species and the total contents of carbon and nitrogen were significantly higher at the unreclaimed plots compared to reclaimed plots. The biodiversity values and evapotranspiration function rate were also higher on unreclaimed plots. From this perspective, it is possible to recommend using of spontaneous succession, together with routine reclamation methods to restore habitats after coal mining. Despite the relatively high age of vegetation in some of selected plots (90 years), both the reclaimed and unreclaimed plots have not reached the stage of potential vegetation near to natural climax. Slow development of vegetation was probably due to unsuitable substrate of spoil heaps and a lack of plant and tree species of natural forest habitats in this area. However, it is probable that vegetation communities on observed spoil heaps in both type of management (reclaimed and unreclaimed) will achieve the stage of natural climax and they will provide ecosystem functions more effectively in the future.

Regional-scale vegetation heterogeneity in northeastern Patagonia: Environmental and spatial components

Our aim was to describe vegetation heterogeneity at a regional scale in northeastern Patagonia and to identify the environmental variables associated to it. The study area encompasses 13 144 km2 and is characterized by a mixture of species typical of Patagonian steppes and Monte Desert. We performed 48 vegetation releves, which were randomly assigned to a training set and to a validation set (32 and 16 releves, respectively). Training set was subjected to cluster analysis, which allowed the identification of two plant communities one related to Patagonian steppes and another to the Monte desert. We derived 3 attributes of the seasonal curve of the NDVI as indicators of ecosystem function: the seasonal amplitude (SA), the date of the maximum (DOM), and the large seasonal integral (LSI). We explored the relationship between NDVI attributes and communities by classification tree analysis. LSI was the strongest predictor among NDVI attributes, separating both communities without misclassification errors. Patagonian steppes occupy areas with higher LSI. The partial RDA analysis explained 38.1% of total data variation, of which 16.5% was ascribed to environment, 7.9% to space, and 13.7% to spatial component of environment. Patagonian steppes are closer to the coast, in areas exhibiting higher annual precipitation and lower annual temperature range than Monte deserts. Our results indicate the occurrence of two plant communities in the study area and highlight the significance of climatic variables to explain their spatial distribution. As most scenarios of future climate predict greater annual thermal amplitude in the study area, the limit between both communities could be displaced eastward.

Do alien and native tree species from Central Argentina differ in their water transport strategy?

In this study we assessed the water transport strategies and the abundance of alien and native tree species at a regional scale in Cordoba Mountains, Central Argentina. The aims of this study were: (i) to analyse whether alien and native tree species show divergent water transport strategies; and (ii) to explore whether species abundances of alien and natives are associated with specific trait attributes. Eight alien species and 12 native species were recorded in 50 complete vascular plant vegetation releves. Water transport strategies were assessed through the following functional traits: minimum leaf water potential, potential water content of wood, effective leaf area, leaf area per sapwood area and wood density. Also, resource use strategies were assessed throughout the measurement of specific leaf area. We found that alien species had a higher efficiency in water transport (i.e. higher minimum leaf water potential and lower wood density values) and faster resource acquisition and use (higher specific leaf area values) than native species. We did not find evidence suggesting that the relative abundance of species was associated to water transport strategies and faster resource acquisition and use. Alien species seem to differ from natives in specific functional attributes that are absent in the resident community and might allow aliens to use more resources and at a higher rate than native species. Finally, our results show the potential of a trait-based predictive framework for alien species, and the possible effects on ecosystem functions.

Assessing the habitat conservation status by soil parameters and plant ecoindicators

Abstract: The aim of this study is to evaluate the conservation status of a Natural Reserve through an integrated approach analysing simultaneously soils, lithotypes, land forms, edaphic parameters and plant species. In focusing the relationships between soil and vegetation, plant ecoindicators, expressed by i) the Ellenberg bioindication model and by ii) the Hemeroby Index, and soil measured parameters were utilized.Vegetation and soil data have been collected simultaneously through thirty vegetation releves and soil profiles. Cluster analysis, performed on matrix 12 variables/ 30 releves allowed a division into two main clusters, each one divided into sub-clusters, distinguished by floristic composition and soil characteristics. The clusters were markedly discriminated by soil Available Water Capacity (AWC). Canonical Correspondence Analysis (CCA), performed on variables and species matrices, allowed to discriminate two main habitats: i) a core habitat represented by patches of temperate forest correlated to soil cycles of water and nutrients; ii) an ecotonal habitat shaped by mixed evergreen and thermophilous deciduous oak forest depending on light, temperature and human disturbance.

Weed vegetation of arable land in the Czech Republic: environmental a management factors determining weed species composition

This paper reports on the current situation in weed vegetation composition on arable land in selected areas of the Czech Republic, assessment of influence of selected variables: applied management systems (conventional, organic), crops (winter cereals, root crops) and altitude and ranking of the importance of these particular factors. A phytocoenological survey was conducted from 2006 to 2008 during a vegetation period using releves that were 100 m 2 in size, placed in the central part of fields. In total, 202 releves of agricultural vegetation were recorded. The combined environmental variables explained 10.6% of the variability. Based on the pCCAs, the highest effect was found at altitude, which explains 5.1% of the species composition variability. The second and third most significant factors are crop and management system, which explain 3.3% and 1.8% of the variability, respectively. The lowlands were generally characterised by the thermophilous summer annual weed species. The higher altitudes were populated by species that are typical for colder areas and poor, humid, and acidic soil types, such as cambisoil.

Expansion of acidophytic late-successional bryophytes in Dutch fens between 1940 and 2000

Question How did frequency and local abundance of key bryophytes in Dutch fens change between 1940 and 2000? Location The Netherlands. Methods A total of 1939 vegetation releves, objectively assigned to the class Parvocaricetea and dating from the period 1940–1999 inclusive, were extracted from a national Netherlands database. From this releve set, two additional data sets were derived; these were syntaxonomically homogeneous at the association level. One contained 418 Scorpidio-Caricetum diandrae releves and the other 956 Pallavicinio-Sphagnetum releves. The following analyses were done for these three data sets: frequency and local abundance change of 13 bryophyte species over three 20-yr periods were described using logistic regression and the nonparametric Jonckheere–Terpstra test, respectively. Results Acidophytic, late-successional species, notably Sphagnum palustre and Polytrichum uliginosum, have replaced relatively early-successional species such as brown mosses, Sphagnum subnitens and Sphagnum squarrosum during the studied period. The results were mostly consistent across the three data sets. Local abundance patterns generally paralleled those of frequency, although cover trends were often less robust. Conclusions Drastic changes have taken place in the bryophyte layer of Dutch fens between 1940 and 2000. Our study has shown that acidophytic, late-successional bryophytes have replaced relatively early-successional brown moss and Sphagnum species. Both hydrological changes and nutrient shifts (in particular phosphorus enrichment and ammonium toxicity) appear to have been responsible for the observed rapid shifts in the bryophyte layer of Dutch fens.

Application of the Ancient Forest Concept to Potential Natural Vegetation Mapping in Flanders, A Strongly Altered Landscape in Northern Belgium

Construction of potential natural vegetation (PNV) poses particular challenges in landscapes heavily altered by human activity and must be based on transparent, repeatable methods. We integrated the concept of ancient forest (AF) and ancient forest species (AFS) into a four-step procedure of PNV mapping: 1) classification of forest vegetation releves; 2) selection of those vegetation types that can serve as PNV units, based on AF and AFS; 3) merging of selected vegetation types into five PNV units that can be predicted from a digital morphogenetic soil map; 4) mapping of three additional PNV units based on additional environmental data. The second step, concerning the selection of reference forest vegetation, is of particular interest for PNV construction in Flanders (northern Belgium), where forest cover has been subject to temporal disruption and spatial fragmentation. Among the variety of extant forest recovery states, we chose as PNV units those vegetation types for which a high proportion of releves had been located in AF and that contained many AFS. As the frequency of AFS depends on site conditions, we only compared and selected vegetation types that are found on similar sites according to average Ellenberg indicator values. While succession is irrelevant for the definition of PNV, colonization rates of AFS can be used to estimate the time required for PNV to be restored in a site.

Vegetation Database of Oak Communities in Turkey

In Turkey, approximately 20,000 vegetation releves do exist in total. However, there is no central database for Turkish vegetation releves at present (2011). I started building the Vegetation Database of Oak Communities in Turkey (GIVD ID AS-TR-002) from published and unpublished data such as master and PhD theses, reports and articles in local and international journals. In total, 1,181 releves were entered in TURBOVEG format for oak vegetation releves, including woodlands and forests. Plots were georeferenced using the Google Earth plugin integrated in the TURBOVEG software. Typical header data, such as altitude or aspect were entered when available. Most of the releves belong to the vegetation classes Quercetea ilicis and Quercetea pubescentis.

Vegetation Database of the Grassland Communities in Anatolia

In Turkey approximately 20,000 vegetation releves do exist. However, there is no central database for Turkish vegetation releves. We started building a vegetation database based on grassland vegetation releves from published and unpublished data from Turkey. The database contains dune, steppic, alpine and subalpine grassland vegetation. Approximately 1,878 releves have been entered in TURBOVEG format. Plots were georeferenced using the Google Earth plugin integrated in the TURBOVEG software. Typical header data were entered when available. Most of the releves belong to the classes Astragalo-Brometea and DaphnoFestucetea. This report describes the available content in the Vegetation Database of the Grassland Communities in Anatolia (GIVD ID AS-TR-001).