Albert et al. (2014) Applied Vegetation Science

Ágnes-Júlia Albert, András Kelemen, Orsolya Valkó, Tamás Miglécz, Anikó Csecserits, Tamás Rédei, Balázs Deák, Béla Tóthmérész & Péter Török (2014): Secondary succession in sandy old-fields: a promising example of spontaneous grassland recovery. Applied Vegetation Science, DOI: 10.1111/avsc.12068, PDF itt

Abstract
Question: Based on the spontaneous vegetation development of old-fields in the Nyírség and Kiskunság sand regions (Hungary), we aimed to answer the following questions using the chronosequencemethod: (1) how do the proportions of different functional groups change during succession; (2) which target species establish successfully in the old-fields during the course of succession; and (3) how successful is spontaneous succession in the recovery of target grasslands?
Location: Two sand regions of the Great Hungarian Plain: (1) the Nyírség sand region (East Hungary, acidic sand, moderately continental climate) and the Kiskunság (Central Hungary, calcareous sand, continental climate).
Methods: Altogether 24 old-fieldswere classified into young (<10-yr-old),middle-aged (10–20-yr-old) and late-succession (20–40-yr-old) old-fields; four fields in each age category. For baseline vegetation reference, three open and three closed sand grassland stands in both regions were sampled in the vicinity of the old-fields. The percentage cover of vascular plants was recorded in five 2 9 2-m plots in each field, in early May and late June 2012. We used life forms, clonal spreading traits and Ellenberg indicator values for nutrients in the analysis. Species of Festuco-Brometea class were considered as target species.
Results: The cover of hemicryptophytes and geophytes increased, the cover of short-lived species decreased with time. Cover of species without clonal spreading ability decreased, while cover of species with clonal spreading ability increased with increasing field age. The cover of invasive species decreased with increasing field age. The majority of target species had established already in the young and middle-aged old-fields, although their cover was significantly higher in the two older age groups.
Conclusion: Spontaneous succession can be a vital option in recovery of sand grassland vegetation in Central Europe; the majority of the species pool of sandy grasslands can be recovered in the first 10–20 yrs. However, the success of grassland recovery can be strongly influenced by the surrounding species pool and can be slowif seed dispersal is limited. Spontaneous succession ismost promising when the target species of grasslands immigrate at the very beginning of the succession, within the first few years.


Keywords
abandonment, acidic sand, calcareous sand, clonal traits, grassland restoration, invasion, spontaneous succession

Király et al. (2013) Preslia

Király G., Trávníček B. & ŽílaV. (2013): Revision of Rubus ser. Micantes occurring in Hungary and re-evaluation of the neglected Rubus balatonicus. Preslia 85: 505–526.

Abstract
Rubus balatonicus Borbás, belonging to ser. Micantes Sudre and a long-neglected apomictic species occurring in Hungary, is herein re-evaluated. This species is a nemophilous bramble occurring in the Transdanubian Mts (central Hungary) and has distinctive morphological features that clearly differ from those of related species. A list of localities and a distribution map are presented in addition to the designation of a lectotype and the description and first complete illustration of this species. As part of a general revision of Rubus ser. Micantes occurring in Hungary, the characteristics, distribution and ecology of three additional species (R. clusii Borbás, R. styriacus Halácsy and R. tabanimontanus Figert) of this series reported from Hungary are also assessed.

Keywords
biogeography, distribution, ecology, Hungary, Rubus, ser. Micantes, taxonomy

Király et al. (2013) Biologia

Gergely Király, András Bidló, Gábor Takács, Pavol Eliáš jun., Zuzana Melečková & Daniel Dítě (2013): Remote locality of the littoral Carex extensa (Cyperaceae) in Hungary – long distance dispersal from coastal to inland salt marshes. Biologia 68(5): 872—878.

Abstract

A remarkable population of Carex extensa (Cyperaceae) was found south of Lake Fertő (Neusiedler See) in Hungary in 2012. This species typically occurs in coastal salt marshes in Europe and was hitherto unknown from the Pannonian Basin. The locality is situated in a territory which has been embanked in 1911. Keeping also in mind that the vegetation developed here from reed beds to saline habitats, we conclude that C. extensa reached the salt marshes of the area through long distance dispersal by water birds from the European coast in the last century. Nevertheless, several other maritime littoral species grow in the region, and the possibility that there is a hidden population of C. extensa at another site(s) nearby cannot be excluded. Lake Fertő is often described as the “westernmost steppe lake” and supports one of the richest European inland littoral floras. Although it appears likely that C. extensa has only recently colonised the site, we consider this discovery to be of significant biogeographical importance.

Keywords

Juncion maritimi, biogeography, drainage, landscape history, long distance dispersal, salt marshes

Biró et al. (2013) Community Ecology

M. Biró, K. Szitár, F. Horváth, I. Bagi, Zs. Molnár (2013): Detection of long-term landscape changes and trajectories in a Pannonian sand region: comparing land-cover and habitat-based approaches at two spatial scales. Community Ecology 14(2): 219-230. DOI: 10.1556/ComEc.14.2013.2.12


Abstract
A key driver of biodiversity loss is human landscape transformation. Change detection and trajectory analysis are frequently applied methods for studying landscape change. We studied to what degree habitat-specific change detection and trajectory analysis provide different information on landscape change compared to the analysis with land-cover statistics. Our research was carried out at two spatial scales (regional, 1800 km2, 360 random points; local, 23 km2, polygon-based maps) in the Kiskunság, Hungary. Spatio-temporal databases were prepared using historical maps, aerial photos and satellite images from 1783, 1883, 1954, and 2009. Local expert knowledge of landscape history and recent vegetation was used during the historical reconstructions. We found large differences at both scales between land-cover based and habitat-specific analyses. Habitat-specific change detection revealed that grassland loss was not continuous in the different habitats, as land-cover based analysis implied. Ploughing affected open sand grasslands and sand steppes differently in the periods studied. It was only apparent from the habitat-specific analyses that from the grasslands only mesotrophic and Molinia meadows were relatively constant, up until the 1950s. The gradual increase in forest area revealed by land-cover CHD analyses was split into natural and anthropogenic processes by habitat-specific analyses. Habitat specific trajectory analysis also revealed ecologically important historical differences between habitats. Afforestation affected especially the open sand grasslands, whereas wetland habitats were relatively stable. The most important trajectory was the one in which closed sand steppes were ploughed during the 19th century, and remained arable fields until present. Fifty percent of the regional trajectories of 18th century open sand grasslands terminated in tree plantations at present, though 82% of the current open sand grasslands of the local site can be regarded as ancient. We concluded that dividing land-cover categories into finer habitat categories offered an opportunity for a more precise historical analysis of key habitats, and could reveal important ecological processes that cannot be reconstructed with land-cover based analyses. It also highlighted habitat-specific processes making natural and social drivers better interpretable. Information on the diversity of habitat-histories may serve as a basis for spatially more explicit conservation management.


Keywords
Change detection analysis, Habitat change, Habitat continuity, Land-cover change, Regional scale

Mücke et al. (2013) Canadian Journal of Remote Sensing

Mücke, W., Deák, B., Schroiff, A., Hollaus, M., Pfeifer N. (2013): Estimation of dead wood using small footprint airborne laser scanning data. Canadian Journal of Remote Sensing. DOI: 10.5589/m13-013
URL: http://pubs.casi.ca/doi/abs/10.5589/m13-013


Abstract
Deadwood was identified as an important indicator for habitat condition and biodiversity in forests. The assessment of downed trees is therefore part of sustainable forest management and ecological monitoring. However, manual quantification of deadwood in forests is challenging, time consuming, and considered cost-inefficient. Full-waveform airborne laser scanning (FWF-ALS) can be used to support the assessment process. The amplitude and width of the backscattered pulses contain information on the properties of the surface. We used these observations for the identification of downed trees in a Natura2000 forest site. A high density FWF-ALS data set was acquired under leaf-off conditions. Echo width and type (i.e., first,intermediate, and last) information as well as normalized echo heights were used to filter the point cloud and derive a digital height model (DHM). This DHM depicts downed stems as line-like features. Image processing was applied to derive and refine regions representing fallen trees. Terrestrial reference data consisting of locations and dimensions of downed trees, as well as state of decay were used for evaluation. Direct identification of downed trees in FWF-ALS point clouds was possible (completeness 75%, correctness 90%), but it was influenced by factors such as dimension, state of decay, vegetation density, and penetration of the laser.

Valkó et al. (2013) Basic and Applied Ecology

Orsolya Valkó, Péter Török, Balázs Deák, Béla Tóthmérész (2013): Prospects and limitations of prescribed burning as a management tool in European grasslands. Basic and Applied Ecology, in press. http://dx.doi.org/10.1016/j.baae.2013.11.002


Abstract
Grassland managers and scientists are increasingly interested in cost-effective alternative ways of grassland biodiversity conservation. Prescribed burning is a promising management tool which should be integrated in the planning of management efforts. In addition, small-scale prescribed burning is an effective fire suppression strategy to decrease the serious negative impacts of uncontrolled burnings on ecosystems and human life. Prescribed burning forms an integral part of the North-American grassland management practice, while in Europe it is rarely applied, despite the fact that uncontrolled burning occurs frequently in some regions. Our goal was to evaluate the use of prescribed burning as a promising but neglected management tool in European grasslands. We found that European studies on prescribed burning of grasslands are scarce and we conclude that annual burning is usually not an appropriate option for the conservation of species-rich grasslands. We reviewed burning studies from North-America to identify findings which might be adapted to the European grassland conservation strategy. In North-America, contrary to Europe, the application of burning is fine tuned in terms of frequency and timing, and usually combined with other restoration measures (grazing or seed sowing). Thus, we conclude that with the application of carefully designed prescribed burning, multiple conservation goals, e.g. invasion control and enhancing landscape-level heterogeneity, can be linked with an effective fire suppression strategy. We emphasize that for the application of prescribed burning in Europe, the general findings of carefully designed case studies should be combined with the practical knowledge of conservation managers concerning the local application circumstances to reach specific management objectives.


Keywords
Biomass, Ecosystem services, Fire, Grazing, Mowing, Prairie

Zlinszky et al. (2012) Remote Sensing

A. Zlinszky, W. Mücke, H. Lehner, C. Briese, N. Pfeifer (2012): Categorizing Wetland Vegetation by Airborne Laser Scanning on Lake Balaton and Kis-Balaton, Hungary". Remote Sensing, 4 (6): 1617-1650.

Abstract
Outlining patches dominated by different plants in wetland vegetation provides information on species succession, microhabitat patterns, wetland health and ecosystem services. Aerial photogrammetry and hyperspectral imaging are the usual data acquisition methods but the application of airborne laser scanning (ALS) as a standalone tool also holds promises for this field since it can be used to quantify 3-dimensional vegetation structure. Lake Balaton is a large shallow lake in western Hungary with shore wetlands that have been in decline since the 1970s. In August 2010, an ALS survey of the shores of Lake Balaton was completed with 1 pt/m2 discrete echo recording. The resulting ALS dataset was processed to several output rasters describing vegetation and terrain properties, creating a sufficient number of independent variables for each raster cell to allow for basic
multivariate classification. An expert-generated decision tree algorithm was applied to outline wetland areas, and within these, patches dominated by Typha sp. Carex sp., and Phragmites australis. Reed health was mapped into four categories: healthy, stressed, ruderal and die-back. The output map was tested against a set of 775 geo-tagged ground photographs and had a user’s accuracy of >97% for detecting non-wetland features (trees, artificial surfaces and low density Scirpus stands), >72% for dominant genus detection and >80% for most reed health categories (with 62% for one category). Overall classification accuracy was 82.5%, Cohen’s Kappa 0.80, which is similar to some hyperspectral or multispectral-ALS fusion studies. Compared to hyperspectral imaging, the processing chain of ALS can be automated in a similar way but relies directly on differences in vegetation structure and actively sensed reflectance and is thus probably more robust. The data  acquisition parameters are similar to the national surveys of several European countries, suggesting that these existing datasets could be used for vegetation mapping and monitoring.

Keywords
LIDAR, wetlands, Phragmites australis, Carex, Typha, ecosystem health, vegetation classification

Zlinszky & Tímár (2013) Hydrology and Earth System Sciences

A. Zlinszky, G. Timár (2013): Historic maps as a data source for socio-hydrology: a case study of the Lake Balaton wetland system, Hungary. Hydrology and Earth System Sciences 17: 4589 - 4606.

Abstract

Socio-hydrology is the science of human influence on hydrology and the influence of the water cycle on human social systems. This newly emerging discipline inherently involves a historic perspective, often focusing on time scales of several centuries. While data on human history is typically available for this time frame, gathering information on the hydrological situation during such a period can prove difficult: measured hydrological data for such long periods are rare, while models and secondary datasets from geomorphology, pedology or archaeology are typically not accurate enough over such a short time. In the first part of this study, the use of historic maps in hydrology is reviewed. Major breakthroughs were the acceptance of historic map content as valid data, the use of preserved features for investigating situations earlier than the map, and the onset of digital georeferencing and data integration. Historic maps can be primary quantitative sources of hydro-geomorphological information, they can provide a context for point-based measurements over larger areas, and they can deliver time series for a better understanding of change scenarios.

In the second part, a case study is presented: Water level fluctuations of Lake Balaton were reconstructed from maps, levelling logs and other documents. An 18th century map system of the whole 5700 km2 catchment was georeferenced, integrated with two 19th century map systems, and wetlands, forests and open water digitized. Changes in wetland area were compared with lake water level changes in a 220-year time series. Historic maps show that the water level of the lake was closer to present-day levels than expected, and that wetland loss pre-dates drainage of the lake.

The present and future role of historic maps is discussed. Historic hydrological data has to be treated with caution: while it is possible to learn form the past, the assumption that future changes will be like past changes does not always hold. Nevertheless, old maps are relatively accessible datasets and the knowledge base for using them is rapidly growing, and it can be expected that long-term time series will be established by integrating georeferenced map systems over large areas.

In the Appendix, a step-by-step guide to using historic maps in hydrology is given, starting from finding a map, through georeferencing and processing the map to publication of the results.

Mahon et al. (2013) Forest Ecology and Management

Mahon, C. L., Bayne, E. M., Sólymos, P., Matsuoka, S. M., Carlson, M., Dzus, E., Schmiegelow, F. K. A., Cumming, S. G., & Song, S. J. (2013): Does expected future landscape condition support proposed population objectives for boreal birds? Forest Ecology and Management, DOI: 10.1016/j.foreco.2013.10.025

URL: http://www.sciencedirect.com/science/article/pii/S0378112713006920

Abstract
Assessing the feasibility of proposed Bird Conservation Region (BCR) population objectives requires comparing expected future population size estimates to proposed population objectives. Linking statistical bird habitat models with landscape simulation models can provide a direct method for assessing the ecological and economic implications of alternative land and resource scenarios within a BCR or BCR sub-region. We demonstrate our approach for analyses of future habitat supply and population size for a suite of priority landbird species using the ALCES® landscape simulation model and empirical bird habitat models within a multi-use landscape located in northeast Alberta, Canada and BCR 6-Boreal Taiga Plans. We used ALCES® to simulate future landscape condition over a 100 year time period under three scenarios: business as usual, protected areas, and climate change. Shortfalls between simulated population size estimates at year 30 and proposed population objectives existed for each of the four priority bird species examined suggesting that expected future landscape condition will not support proposed population objectives for these species. Boreal species strongly associated with mature and old forest habitats exhibited population declines over the 100 year simulation period. One habitat generalist, a species associated with both early and late seral stages, appeared to benefit from the range of land use scenarios examined. Our approach improves upon current static approaches used to step down BCR scale population objectives to sub-regional scale habitat objectives by utilizing statistical bird population response models to estimate density and a dynamic landscape simulation model to estimate expected future habitat condition.

Keywords
Bird Conservation Regions, Boreal forest, Landscape simulation model, Land use scenarios, Partners in Flight, Population objectives

Bereczki et al. (2013) Journal of Zoological Systematics and Evolutionary Research

Bereczki, J., Tóth, J. P., Sramkó, G. and Varga, Z. (2013): Multilevel studies on the two phenological forms of Large Blue (Maculinea arion) (Lepidoptera: Lycaenidae). Journal of Zoological Systematics and Evolutionary Research. DOI: 10.1111/jzs.12034

Abstract
The main goal of our research was to study comprehensively the differences between the two phenological forms of the socially parasitic and globally threatened Large Blue (Maculinea arion) in the Carpathian Basin using four character sets (mitochondrial sequences, allozymes, male genitalia and wing morphometrics). Comparative analyses of distance matrices, phylogenetic trees and ordination patterns have been applied. The genetic and morphometric patterns revealed by our studies were discordant. While we experienced a significant differentiation between the ‘spring’ and ‘summer type’ of M. arion in both wing and genital traits, the two phenological forms did not show any genetic differentiation on two mitochondrial loci and in allozymes. At the same time, all individuals were infected by Wolbachia. Although certain wing traits may not represent reliable tracers of phylogeny because of the particular adaptive significance, the wing characteristics involved in our research are probably determined genetically. Additionally, the significant differentiation of male genitalia also indicates incipient prezygotic isolation arising from phenological differentiation between the ‘spring and summer arion’. It is possible that all extant differences between the two forms are attributable to (1) different host-ant use, (2) incipient speciation, (3) cytoplasmatic incompatibility (CI) by Wolbachia or the combination of these factors. In addition, discordant results indicate that the combined use of different approaches and data sets is strictly necessary to clarify systematic and evolutionary relationships.

Keywords
Spring and summer arion, mtDNA variability, Wolbachia, geometric morphometry, Carpathian Basin

Loreto et al. (2013) Global Ecology and Biogeography

Loreto, F., Bagnoli, F., Calfapietra, C., Cafasso, D., De Lillis, M., Filibeck, G., Fineschi, S., Guidolotti, G., Sramkó, G., Tökölyi, J. and Ricotta, C. (2013): Isoprenoid emission in hygrophyte and xerophyte European woody flora: ecological and evolutionary implications. Global Ecology and Biogeography doi: 10.1111/geb.12124

Abstract
Aim
The relationship between isoprenoid emission and hygrophily was investigated in woody plants of the Italian flora, which is representative of European diversity.
Methods
Volatile isoprenoids (isoprene and monoterpenes) were measured, or data collected from the literature, for 154 species native or endemic to the Mediterranean. The Ellenberg indicator value for moisture (EIVM) was used to describe plant hygrophily. Phylogenetic analysis was carried out at a broader taxonomic scale on 128 species, and then refined on strong isoprene emitters (Salix and Populus species) based on isoprene synthase gene sequences (IspS).
Results
Isoprene emitters were significantly more common and isoprene emission was higher in hygrophilous EIVM classes, whereas monoterpene emitters were more widespread and monoterpene emission was higher in xeric classes. However, when controlling for phylogeny, isoprene emission was not associated with EIVM, possibly due to the large presence of Salicaceae among hygrophilous isoprene emitters. Moreover, the distribution of isoprene emitters among EIVM classes was not related to IspS-based phylogenesis in Populus and Salix, suggesting that the gene has not undergone evolution linked to ecological pressure. In contrast, the monoterpene emission pattern is independent of phylogeny, suggesting that the evolution of monoterpenes is associated with transitions to more xeric habitats.
Main conclusions
Our results reveal an interesting ecological pattern linking isoprenoids and water availability. We suggest that isoprene is a trait that: (1) evolved in plants adapted to high water availability; (2) is replaced by more effective protection mechanisms, e.g. more stable isoprenoids, in plants adapting to more xeric environments; and (3) being strongly constrained by phylogeny, persists in Salicaceae adapted to more xeric environments.

 

Keywords
Adaptation, chemo-taxonomy, hygrophytes, isoprene, monoterpenes, phylogenies, salicaceae, xerophytes, water stress

Halme et al. (2013) Biological Conservation

Panu Halme, Péter Ódor, Morten Christensen, Andrej Piltaver, Mirjam Veerkamp, Ruben Walleyn, Irén Siller, Jacob Heilmann-Clausen (2013): The effects of habitat degradation on metacommunity structure of wood-inhabiting fungi in European beech forests. Biological Conservation 168: 24–30. http://dx.doi.org/10.1016/j.biocon.2013.08.034


Abstract
Intensive forest management creates habitat degradation by reducing the variation of forest stands in general, and by removing old trees and dead wood in particular. Non-intervention forest reserves are commonly believed to be the most efficient tool to counteract the negative effects on biodiversity, but actual knowledge of the conservation efficiency is limited, especially for recent reserves. The structure of ecological communities is often described with measures of nestedness, beta diversity and similarity between communities. We studied whether these measures differ among forest reserves with different management histories. For this purpose, we used a large data set of wood-inhabiting fungi collected from dead beech trees in European beech-dominated forest reserves. The structure of fungal assemblages showed high beta diversity, while nestedness and similarity was low. During the decomposition process of trees beta diversity between the communities occupying different trees increased in natural, but not in previously managed sites. Effects of management and decay process on nestedness were complex. We argue that the detected differences most likely reflect historical effects which have extirpated specialized species from the local species pools in managed sites, and resulted in more homogeneous communities in managed sites. It is alarming that community structure is affected the most in the latest decay stages where the decay process turns the dead wood into litter, and which is thus the interface between the wood decay and the litter-decaying ecosystem. The effects of simplified communities in late decay stages on soil biodiversity should be studied.


Keywords
Beta diversity, Decay stage, Forest management, Nestedness, SDR simplex, Similarity

Ökológus Tea, 2013 őszi program

Szeretettel várjuk programjainkra! 
Minden előadás előtt küldök meghívót a levelezési 
lista tagjainak. A listára itt lehet jelentkezni. 

2013. szeptember 30, 16 óra

Podani János (ELTE Növényrendszertani, Ökológiai és Elméleti Biológiai Tsz.):

Új megközelités ökológai adatok struktúrájának feltárásához

2013. október 7, 16 óra

Hubai András és Oborny Beáta (ELTE Növényrendszertani, Ökológiai és Elméleti Biológiai Tsz.):Átkelni vagy maradni? - a növekedő növény optimális válasza a folthatárra

2013. október 14, 16 óra

Buczkó Krisztina és Magyari Enikő (Magyar Természettudományi Múzeum, Növénytár):
Kovavázas algák szinkron válaszai a környezeti változásokra

2013. október 21, 16 óra

Bán Miklós (Debreceni Egyetem, Evolúciós Állattani és Humánbiológiai Tanszék) 
két rövidebb előadást tart:
1) Szabadon használható adatbázis keretrendszer biológiai térképi adatok számára
2) Egy újabb trükk a kakukk-gazda kapcsolatban

2013. november 4, 16 óra

Liker András (Pannon Egyetem, Limnológiai Intézeti Tanszék): 

A felnőttkori ivararány és a szaporodási viselkedés kapcsolata madaraknál

2013. november 18, 16 óra

Engloner Attila (ELTE Növényrendszertani, Ökológiai és Elméleti Biológiai Tsz.):

2013. november 25, 16 óra

Gallé László (Szegedi Egyetem, Ökológiai Tanszék)

2013. december 2, 16 óra

Lengyel Attila (ELTE Növényrendszertani, Ökológiai és Elméleti Biológiai Tsz.)

Helyszín: ELTE TTK, Lágymányosi Campus 
   Budapest XI. ker, Pázmány P. stny. 1/c = Déli Tömb, 
   7. emelet 206. terem (a Dunával ellentétes oldalon)

Okologus Tea, link: https://sites.google.com/site/okologustea/

Cunning et al. (2013) Ecography

Cumming, S., Stralberg, D., Lefevre, K., Sólymos, P., Bayne, E., Fang, S., Fontaine, T., Mazerolle, D., Schmiegelow, F. & Song, S. (2013): Climate and vegetation hierarchically structure patterns of songbird distribution in the Canadian boreal region. Ecography, 36: in press. DOI: 10.1111/j.1600-0587.2013.00299.x, URL: http://onlinelibrary.wiley.com/doi/10.1111/j.1600-0587.2013.00299.x/abstract


Abstract
Environmental factors controlling the distribution and abundance of boreal avifauna are not fully understood, limiting our ability to predict the consequences of a changing climate and industrial development activities underway. We used a compilation of avian point-count data, collected over 1990–2008 from nearly 36 000 locations, to model the abundance of individual forest songbird species within the Canadian boreal forest. We evaluated 30 vegetation and 101 climatic variables, representing most of the widely-used dimensions of climate space, along with less usual measures of inter-annual variability. Regression tree models allowed us to calculate the relative importance of climate and vegetation variable classes according to avian migration strategy without the need for a priori variable selection or dimension reduction. We tested for hierarchical habitat selection by formulating hypotheses on the locations of variables within the model tree structures. Climate variables explained the majority (77%) of deviance explained over 98 species modelled. As may be expected at high latitudes, we found energy availability (temperature, 65%) to be more important than moisture availability (precipitation, 12%). The contributions of inter- and intra-annual climate variability (28%) were about half that of mean conditions. The relatively large contribution of remotely-sensed vegetation metrics (23%) highlighted the importance of local vegetation heterogeneity controlled by non-climatic factors. The two most important vegetation variables were landcover type and April leaf area index. When selected, these generally occurred in a model's right subtree, consistent with predictions from hierarchical habitat selection theory. When occupying the root node, landcover effectively delineated the historical forest-prairie ecotone, reflecting the current disequilibrium between climate and vegetation due to human land use. Our findings suggest a large potential for avian distributional shifts in response to climate change, but also demonstrate the importance of finer scale vegetation heterogeneity in the spatial distribution of boreal birds.

Giokas et al. (2013) Evolutionary Ecology

Sinos Giokas, Barna Páll-Gergely, Onoufrios Mettouris (2013) Nonrandom variation of morphological traits across environmental gradients in a land snail. Evolutionary Ecology, DOI 10.1007/s10682-013-9676-5

Abstract

Morphological variation is often attributed to differential adaptations to diverse habitats, but adaptations to a similar environment do not necessarily result in similar phenotypes. Adaptations for water and heat budget are crucial for organisms living in arid habitats, and in snails, variation in shell morphology has been frequently attributed to selection by stressful environmental factors. However, their phenotypic divergence often is not accompanied by a relevant niche differentiation and consistent relationships with environmental correlates are lacking. In the pulmonate genus Albinaria, there is great size and shape variation between and within species, and there are two major shell sculpture morphotypes, ribbed and smooth. We used 62 populations of 28 Albinaria species, taking into account their phylogeny, to examine the variation of shell traits (sculpture, size, shape), their effect on water and heat budget, and their association with geographical and climatic gradients. We found unambiguous size and shape discrimination between the two morphotypes. Ribbed shells are lighter, taller, and slimmer and have a smaller aperture than the smooth ones. Moreover, significant correlations between shell traits and heat/moisture budget and climate/geography were revealed. Ribbed and taller shells retain more water on their shell surface, and on the other hand, smooth shells exhibit lower water permeability. Therefore, two strategies are being used to prevent water loss, active retention or resistance to loss. Consequently, different alternative solutions evolved and were retained as responses to the same stressful factor by the two distinct shell morphotypes. Larger shells occur in southern latitudes, mostly on islands, and at sites where there is a shortage of rainfall. Therefore, the variation of the examined traits is nonrandom with respect to location and to climate and their evolution can be attributed to selection by environmental factors, with water availability being the key driving agent of body-size variation.

Keywords

Sculpture, Size, Shape, Adaptation, Tradeoff, Environmental gradients

Habel et al. (2013) Biodiversity and Conservation

Jan Christian Habel, Jürgen Dengler, Monika Janišová, Péter Török, Camilla Wellstein, Michal Wiezik (2013) European grassland ecosystems: threatened hotspots of biodiversity.Biological Conservation 22(10): 2131-2138.


Abstract
Biodiversity is not homogenously distributed over the globe, and ecosystems differ strongly in the number of species they provide. With this special issue we highlight the ecology and endangerment of one of the most diverse ecosystem of Europe: the European grassland ecosystems. The selected 16 contributions describe interactions from below-ground to the atmosphere and focus on (1) effects of abiotic and biotic on species diversity, (2) the impact of various factors along spatial and temporal gradients, (3) the relevance of falling abandoned and eutrophication—including countervailing management strategies like encroachment; and (4) intraspecific effects based on physiology, genetics and intraspecific plasticity. The contributions cover fungi, plants, and invertebrates and highlight effects taking place at the level of ecosystem, species community, species, populations, and also within individuals (physiology and genetics).


Keywords
Abandonment, Animal assemblage, Conservation management, Diversity hotspot, Eutrophication, Plant community, Species richness

Endresz et al. (2013) Community Ecology

Endresz, G., Somodi, I. & Kalapos, T. 2013: Arbuscular mycorrhizal colonisation of roots of grass species differing in invasiveness. Community Ecology 14: 67-76.

Abstract
Recent research indicates that the soil microbial community, particularly arbuscular mycorrhizal fungi (AMF), can influence plant invasion in several ways. We tested if 1) invasive species are colonised by AMF to a lower degree than resident native species, and 2) AMF colonisation of native plants is lower in a community inhabited by an invasive species than in an uninvaded resident community. The two tests were run in semiarid temperate grasslands on grass (Poaceae) species, and the frequency and intensity of mycorrhizal colonisation, and the proportion of arbuscules and vesicles in plant roots have been measured. In the first test, grasses representing three classes of invasiveness were included: invasive species, resident species becoming abundant upon disturbance, and non-invasive native species. Each class contained one C3 and one C4 species. The AMF colonisation of the invasive Calamagrostis epigejos and Cynodon dactylon was consistently lower than that of the non-invasive native Chrysopogon gryllus and Bromus inermis, and contained fewer arbuscules than the post-disturbance dominant resident grasses Bothriochloa ischaemum and Brachypodium pinnatum. The C3 and C4 grasses behaved alike despite their displaced phenologies in these habitats. The second test compared AMF colonisation for sand grassland dominant grasses Festuca vaginata and Stipa borysthenica in stands invaded by either C. epigejos or C. dactylon, and in the uninvaded natural community. Resident grasses showed lower degree of AMF colonisation in the invaded stand compared to the uninvaded natural community with F. vaginata responding so to both invaders, while S. borysthenica responding to C. dactylon only. These results indicate that invasive grasses supposedly less reliant on AMF symbionts have the capacity of altering the soil mycorrhizal community in such a way that resident native species can establish a considerably reduced extent of the beneficial AMF associations, hence their growth, reproduction and ultimately abundance may decline. Accumulating evidence suggests that such indirect influences of invasive alien plants on resident native species mediated by AMF or other members of the soil biota is probably more the rule than the exception.


Keywords
Arbuscular mycorrhizal fungi, Calamagrostis epigejos, Cynodon dactylon, Grasses, Invasive plants, Semiarid temperate grassland

Horváth et al. (2013) Biodiversity and Conservation

Roland Horváth, Tibor Magura, Csaba Szinetár, János Eichardt, Béla Tóthmérész (2013): Large and least isolated fragments preserve habitat specialist spiders best in dry sandy grasslands in Hungary. Biodiversity and Conservation 22 (10): 2139-2150.


Abstract
The role of fragment size, isolation and habitat diversity in the conservation of spider assemblages living in fragmented landscape were studied in dry sandy grasslands (East Hungary, Nyírség). Spiders were collected using pitfall traps at eight dry grassland fragments from 2001 to 2009 from March to October fortnightly. We tested the rules of island biogeography, which suggest that the species richness increases with the size and decreases with the isolation of fragments. The habitat diversity is an important factor for species richness, since large areas usually have more habitats; therefore, the number of species may be higher in these areas. During the 9-year study period, altogether 10,544 individuals belonging to 106 species were collected. Contradicting the classical theory, we found a significant negative relationship between the total number of spider species and the grassland size, while the ratio of sandy grassland specialist spider species increased with fragment size. The relationship between the ratio of generalist species and the fragment size was not significant. The overall species richness and the isolation of studied grasslands did not show a significant relationship. The ratio of sandy grassland specialist species decreased, while the ratio of generalist species increased with the increasing of isolation. The habitat diversity did not show any effect on spider species richness. We concluded that to conserve the habitat specialist species it is recommended to preserve the large and least isolated grassland fragments, furthermore to increase the size of small fragments with the restoration of the adjacent croplands.


Keywords

Island biogeography, Fragmentation, Species richness, Sandy grassland specialist species, Generalist species, Habitat heterogeneity

Bácsi et al. (2013) Hydrobiologia

István Bácsi, Tamás Török, Viktória B-Béres, Péter Török, Béla Tóthmérész, Alex Sándor Nagy, Gábor Vasas (2013): Laboratory and microcosm experiments testing the toxicity of chlorinated hydrocarbons on a cyanobacterium strain (Synechococcus PCC 6301) and on natural phytoplankton assemblages. Hydrobiologia 710 (1): 189-203.


Abstract
In the last few years, halogenated hydrocarbons have been detected in the soil, in the aquatic environment, in organisms, and even in drinking water. The toxic effects of three chlorinated aliphatic hydrocarbons (trichloroethylene, tetrachloroethylene and tetrachloroethane) were studied in laboratory experiments (using the cyanobacterium Synecococcus elongatus PCC 6301 as test organism) and in field-like circumstances (natural phytoplankton assemblages enclosed in microcosms). The results of the laboratory experiments showed that all of the tested compounds significantly inhibited the growth of the cultures within the first 4 h. Enzymatic changes of the treated cultures suggested that oxidative stress occured—all of the three compounds caused an increase in the activity of peroxidases and superoxide dismutase, and also increased the levels of lipid peroxidation. Observed changes in microcosms were comparable with the results of the laboratory experiments: the number of individuals and chlorophyll contents decreased in the treated assemblages. The elevated levels of peroxidation on the second day in the assemblages treated with tetrachloroethane and tetrachloroetylene suggest that oxidative stress could occur in field conditions. One of the most important findings is the decrease in species number. Our results showed that cryptomonads, some green algae species and the cyanobacterium Limnothrix gradually disappeared from the treated beakers during the experiment.


Keywords
Chlorinated hydrocarbons, Growth inhibition, Oxidative stress, Laboratory experiments, Phytoplankton assemblages

Sólymos et al. (2013) Methods in Ecology and Evolution

Sólymos, P., Matsuoka, S. M., Bayne, E. M., Lele, S. R., Fontaine, P., Cumming, S. G., Stralberg, D., Schmiegelow, F. K. A. & Song, S. J. (2013): Calibrating indices of avian density from non-standardized survey data: making the most of a messy situation. Methods in Ecology and Evolution, DOI: 10.1111/2041-210X.12106, URL: http://onlinelibrary.wiley.com/doi/10.1111/2041-210X.12106/abstract

Abstract

1. The analysis of large heterogeneous data sets of avian point-count surveys compiled across studies is hindered by a lack of analytical approaches that can deal with detectability and variation in survey protocols.
2. We reformulated removal models of avian singing rates and distance sampling models of the effective detection radius (EDR) to control for the effects of survey protocol and temporal and environmental covariates on detection probabilities.
3. We estimated singing rates and EDR for 75 boreal forest songbird species and found that survey protocol, especially point-count radius, explained most of the variation in detectability. However, environmental and temporal covariates (date, time, vegetation) affected singing rates and EDR for 73% and 59% of species, respectively.
4. Unadjusted survey counts increased by an average of 201% from a 5-min, 50-m radius survey to a 10-min, 100-m radius survey (n = 75 species). This variability was decreased to 8·5% using detection probabilities estimated from a combination of removal and distance sampling models.
5. Our modelling approach reduced computation when fitting complex models to large data sets and can be used with a wide range of statistical techniques for inference and prediction of avian densities.

Keywords

boreal forest songbirds, conditional maximum likelihood, distance sampling, generalized linear models, point counts, predictive mapping, removal sampling, statistical offsets

Valkó et al. (2013) Agriculture, Ecosystems & Environment

Orsolya Valkó, Béla Tóthmérész, András Kelemen, Edina Simon, Tamás Miglécz, Balázs András Lukács, Péter Török (2013): Environmental factors driving seed bank diversity in alkali grasslands. Agriculture, Ecosystems & Environment http://dx.doi.org/10.1016/j.agee.2013.06.012


Abstract
For an effective conservation and management in grasslands it is essential to understand mechanisms sustaining biodiversity. To gain knowledge is especially crucial in stressed grasslands harbouring a unique flora and fauna, like alkali grasslands. Aboveground vegetation, seed bank and environmental factors were studied in three stands of the following alkali grassland types: (i) Artemisia dry alkali grasslands at highest elevations; (ii) Puccinellia high and (iii) Puccinellia low grasslands at medium to low elevations, and (iv)Juncus wet alkali grasslands at the lowest elevations. We tested the following hypotheses: (i) Seed bank species diversity and density are the highest in the most stressed grassland types, where regeneration by seeds could have a major importance in sustaining vegetation diversity. (ii) Seed bank density of hygrophytes increases with decreasing elevation, because the cover of hygrophytes in the vegetation increases with decreasing elevation. The mean seed bank density ranged from 30,104 up to 51,410 seeds/m2, which is higher than in most dry grasslands. Both the lowest seed bank density and diversity were detected in the most stressed Puccinellia high grasslands; Spergularia salina was the only abundant seed bank species (possessing at least 1000 seeds/m2). These results not supported our first hypothesis. We detected the highest seed densities of almost all hygrophyte species in the lowest-elevatedJuncus grasslands. But, we did not find a significant monotonous correlation between elevation and the overall hygrophyte seed bank density; because most of the hygrophyte species were missing from the seed bank at the medium-elevated, but most saline Puccinellia grasslands. Thus, our results only partly supported the second hypothesis. In total we detected more species in the seed bank than in the aboveground vegetation which emphasises that seed bank plays an important role in sustaining the diversity of alkali grasslands. However, characteristic graminoids possessed no considerable seed bank, except for Juncus compressus (up to 38,619 seeds/m2). We can conclude that persistence and establishment of most alkali grassland species are not supported by the local persistent seed bank.


Keywords
Elevation, Salt marsh, Salinity, Seed density, Seedling emergence, Dispersal

Popiela et al. (2013) Acta Botanica Croatica

Popiela A., Lysko A., Molnár V. A. (2013): Recent distribution of the Euro-Siberian-sub-Mediterranean species Elatine alsinastrum L. (Elatinaceae). – Acta Botanica Croatica 72(2) DOI: 10.2478/v10184-012-0022-8


Abstract
The general distribution of the endangered Euro-Siberian sub-Mediterranean species Elatine alsinastrum L. is provided using literature, web-sources and herbaria dataset. The distribution pattern shows some regularities: occurrence of locations along river valleys, formation of concentrated site clusters in some lowlands, wide distances between locations or site clusters or single locations between their clusters. The distribution patterns in central Europe seem to be rather well related to the history of the human migration in Europe at least since the Late Holocene. The scattered locations on the eastern part of the distribution area are likely to be a consequence of missing information, rather than to the fragmentation of its distribution.


Keywords
Elatine alsinastrum, ephemerophyte, distribution

Sólymos et al. (2013) Frontiers in Ecology and the Environment

Péter Sólymos, Cole Burton, Jim Herbers, Stan Boutin & Jim Schieck (2013) Is accurate location information necessary for repeatability in field-based ecology? Frontiers in Ecology and the Environment 11: 178–178.
DOI: http://dx.doi.org/10.1890/13.WB.010

Szivák et al. (2013) Fundamental and Applied Limnology

Szivák, Ildikó; Móra, Arnold; Méhes, Nikoletta; Bereczki, Csaba; Ortmann-Ajkai, Adrienne; Csabai, Zoltán (2013) Highly variable abiotic environment induced changes in taxonomic and functional composition of headwater chironomid assemblages within a small mountain range. Fundamental and Applied Limnology / Archiv für Hydrobiologie 182(4): 323-335

DOI: http://dx.doi.org/10.1127/1863-9135/2013/0436

Abstract

The spatial variability of Chironomidae larvae assemblages was investigated at 6 near-pristine, temperate headwaters in Hungary. Sites were located within a relatively small mountain range but belong to two different catchment areas characterized by highly variable abiotic conditions. We hypothesised there would be differences in taxonomic composition but not in functional composition between different catchment areas and aimed to assess the primary influencing spatial factors structuring the taxonomic and functional compositions of chironomid assemblages. The spatial distribution of chironomid assemblages was examined 4 times during a 1 year period at microhabitat to catchment scales. At each site, streambed morphology, physicochemical attribute, riparian vegetation, microclimate and hydrology data were collected. Three main traits (saprobic preference, stream zonation preference, functional feeding groups) were used to characterize the functional composition of chironomid assemblages. Sharp differences were detected in taxonomic composition between the two sides of the mountain range within a relatively small spatial distance and moderate, but statistically significant differences in functional composition between catchments. The observed spatial changes in taxonomic and functional composition of midges accompanied changes in physicochemical characteristics, riparian vegetation, microclimate and altitude. Internal microhabitat heterogeneity also played a major role in structuring the taxonomic and the functional patterns of chironomid assemblages.

Keywords

headwater Chironomidae, small mountain range, habitat heterogeneity, spatial variation, taxonomic and functional composition, multivariate approaches

Takács A. et al. (2013) Preslia

Takács A., Schmotzer A., Jakab G., Deli T., Mesterházy A., Király G., Lukács B. A., Balázs B., Perić R., Eliáš P. jun., Sramkó G., Tökölyi J. & Molnár V. A. (2013): Key environmental variables affecting the distribution of Elatine hungarica in the Pannonian Basin. – Preslia 85: 193–207.


Abstract
Elatine hungarica Moesz is a small wetland ephemerophyte that occurs and is classified as extinct, data deficient or a very rare and endangered taxon in most countries in eastern and central Europe. Based on literature and herbarium data, supplemented by 160 field records collected between 1998 and 2011, we present the currently known distribution of this species in the Pannonian Basin, which mostly but not exclusively includes Hungary. Within the Pannonian Basin this species is distributed throughout Hungary, with sporadic occurrences in Romania, Serbia and Slovakia. The temporal distribution of floristic records is very uneven. This species was recorded only in 27 years during the last 213 years (1798–2011). When examining presence/absence data for most of the 20th century, we found a significant correlation between the number of records of this species in a given year and two key, but not independent, environmental variables: rainfall and the extent of the area inundated in the same year. In the more intensively documented period between 1998 and 2010, there is only a significant correlation between the numbers of records of this species and the extent of flooding, which is because there is a delay in the effect of an increase in rainfall. The peak occurrence of records in the 1940s and 1950s is associated with extensive rice production in Hungary. Today, most records are for agricultural fields that are subject to flooding and becoming temporary wetlands. The comparison of recent and past distributions of E. hungarica reveals a consistent and marked regional difference; whereas this species is not rare along the Tisza river and its tributaries, it is markedly scattered in similar habitats near the Danube.


Keywords
ephemerophyte, flooding, Hungary, inland water, Isoëto-Nanojuncetea, Elatinaceae, mapping, rainfall, rice weeds, Romania, Serbia, Slovakia, temporary ponds

Varga et al. (2013) Regional Environmental Change

Katalin Varga, György Dévai, Béla Tóthmérész (2013): Land use history of a floodplain area during the last 200 years in the Upper-Tisza region (Hungary). Regional Environmental Change


Abstract
Research into landscape history makes it possible to follow landscape changes in the past and support landscape management, conservation and restoration programs. Floodplain habitats are lost, isolated and fragmented on account of land use. Nowadays, these habitats are threatened by modifications in the natural water regime, as well as agricultural and forestry practices. Floodplains have great importance because they provide a transition between aquatic habitats and terrestrial biotopes. Our analysis of aerial photographs and topographical maps revealed that the major predicted changes in the study area are related to agricultural abandonment and afforestation. The comparison of land cover maps from 1784 to 2005 showed intensification of agriculture with land cover conversions from arable land and orchards to grasslands, marshes and woodlands. The land use types that are mostly responsible for the fragmentation of the landscape are arable land, economic plantations and orchards. We found that fragmentation was greater after 1956. This was caused by socioeconomic changes and showed that the habitats of floodplains have changed intensively during the last 200 years. Knowledge of this last 200 years of history contributes to a more careful and wiser management of the region through biodiversity protection and environmental development.


Keywords
Landscape change, Habitat map, GIS, MESH, Nearest neighbor, DIVISION

Deák et al. (2012) Applied Ecology and Environmental Research

Deák, Zs., Hufnagel, L., Hajdu, I.-né (2012): The impact of perceived corporate environmental performance on the behavior of capital market decision makers: analysis of food industry companies. Applied Ecology and Environmental Research 10(4): 437-456.

Abstract

Environmental protectionism and sustainable development has been gaining increased attention among governments, investors and consumers alike. As a result, firms are facing growing pressure from the various stakeholders to improve their environmental performance. This study is focusing on the food industry, which in recent years has been a subject of increased scrutiny due to their role in resource consumption, waste generation and unsustainable production practices. Our research is aiming to examine how the financial community evaluates the environmental stewardship of food industry companies as proxied by market reactions in response to environmental news. Are all company related environmental news items evaluated equally, and which financial and non-financial firm-specific attributes can influence market responses? Have there been changes in reactions on the stock exchange in the past two decades?

Keywords

environmental performance, food industry, news impact, stock markets, firm-level variables

Gimesi et al. (2012) Applied Ecology and Environmental Research

Gimesi, L., Homoródi,R., Hirka, A., Szabóki, Cs., Hufnagel, L. (2012): The effect of climatechange on the phenology of moth abundance and diversity. Applied Ecology andEnvironmental Research 10(3): 349-363.

 

 

Abstract
When examining the ecological effects of climate change those databases which contain monitoring results of long-term time series have a key role. We used the daily Lepidoptera data of the Hungarian Plant Protection and Forestry Light Trap Network between 1962 and 2006 to analyse the influence of the change of temperature on the ecological dynamics of Lepidoptera. Using the quantile regression analyses we concluded that in the examined period, for the total number of individuals, seasonal phenomena shifted forward, however the days with higher diversity occurred over a shorter period. The analysis of the heat sums shows that the spring warming started earlier, although, at the same time the low quantiles of the captured Lepidoptera occurred at lower and lower heat sums over the years, while the heat sums at which the high quantiles of the number of Lepidoptera occurred showed a steady increase, meaning that the active period of the Lepidoptera community has expanded. A strong correlation was observed between diversity and temperature.

 

 

Keywords

biodiversity, quantile regression, climate change, Lepidoptera, light trap

Mészáros et al. (2012) Applied Ecology and Environmental Research

Mészáros, G., Tajthy,D., Vadadi-Fülöp Cs., Jablonszky, Gy., Hufnagel, L., Zsuga, K. (2012):Composition of zooplankton assemblages along the Zagyva River. Applied Ecology and Environmental Research 10(3): 291-302.


Abstract

The species composition, longitudinal distribution and seasonal dynamics of zooplankton were studied in the Zagyva River, Hungary. A total of 108 taxa was recorded from which 61 were new for the river. Rotatoria was the most abundant group, microcrustaceans were less important, only nauplii and copepodites were represented in similar individual numbers. Frequent species included Anuraeopsis fissa, Pompholyx spp., Keratella cochlearis, Brachionus angularis, Bdelloida sp., Bosmina longirostris. Dominance of cosmopolitan species was observed both in the river and its reservoir, and species characteristic of eutrophic waters were of major importance in the latter. There was a downstream decrease in zooplankton densities, which was explained by modified conditions. The relatively large number of individuals in autumn months, and the characteristic large number of individuals in the upper section contrasted general findings of potamoplankton dynamics. On the basis of the species abundance matrix, three river sections can be distinguished (upper, middle, lower section). Due to waste water discharges - received from the Tarján Stream - we found extremely high number of individuals and the lowest diversity at the sampling site Nagybátony (148 rkm).


Keywords

Rotatoria, Copepoda, Cladocera, reservoir, spatial distribution

Házi et al. (2012) Applied Ecology and Environmental Research

Házi, J., Penszka, K., Bartha, S., Hufnagel, L., Tóth, A., Gyuricza, Cs., Szentes, Sz. (2012): Cut mowing and grazing effects with grey cattle on plant species composition in case of Pannon wet grasslands. Applied Ecology and Environmental Research 10(3): 223-231.


Abstract
Examined area can be found at Balaton Uplands National Park (Hungary). 5 sample areas were examined in Badacsonytördemic: 1: 32 hectare under-grazed pasture, 2: 38 hectare overgrazed pasture, 3: 34 hectare hayfield, 4: trampled area, 5: beaten track. Livestock population was 118 in the monitored pastures. Sampling was executed along five 52m long circular transects, within 5cm × 5cm interlocking quadrates. Based on the data we can state that the curve of the drinking area was the highest of speciesarea examinations however weed appeared because of degradation which provided more species. According to species-area examinations overgrazed areas were richer in species then other examined areas. Based on diversity data drinking area considered degraded, while meadow and overgrazed areas was considered as proper state. Diversity of meadow was larger, but dominance of economically useful species was smaller. The amount of less valuable species – Carex hirta – increased.



Keywords
grazing, pasture, hayfield, species composition, nature conservation

Szentes et al. (2012) Central European Journal of Biology

Szentes Sz., SutyinszkiZs., Szabó G., Zimmermann Z., Házi J., Wichmann B., Hufnagel L., Penksza K.,Bartha S.: Grazed Pannonian grassland beta-diversity changes due to C4 yellowbluestem. Central European Journal ofBiology 7(6): 1055-1065   DOI:10.2478/s11535-012-0101-9

Abstract

This study investigates how yellow bluestem affects biodiversity in a typical Pannonian grassland. Beta diversity (i.e. the finescale spatial variability of species compositions), was estimated by the realized number of species combinations sampled at various scales. Sampling was performed by a standard protocol. Presences of plant species were recorded along 52.2 m long belt transect of 1044 units of 0.05x0.05 m contiguous microquadrats. According to the results the massive presence of tested C₄ grass significantly reduced species richness of the grassland. Beta diversity assessment revealed that 90% of species combinations were lost due to yellow bluestem invasion. Fine-scale spatial pattern analyses showed complete local extinctions of other species from microsites dominated by yellow bluestem. This local extinction is enhanced by the specific clonal architecture of this species and by the accumulation of litter. Other dominant grasses had no effect on fine scale diversity, i.e. they could coexist well with other elements of the local flora. This study presents currently developed microhabitat types, forecasts and also draws attention to the danger that climate warming will probably enhance the spread of this detrimental C₄ species.

Keywords

Dominant grass, Plant neighbourhood diversity, Litter, Spatial association, Climate change