Information theory methods for the study of spatial processes and succession

Juhász‐Nagy, P.; Podani, János

doi:10.1007/bf00129432

Cited by 86 publications

(68 citation statements)

References 20 publications

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“…This trend is consistent with findings of previous studies (Juhász-Nagy and Podani, 1983;Bartha, 1991;Tóthmérész, 1994;Bartha, 2001) and suggests a general pattern typical in regeneration process (Bartha, 2001(Bartha, , 2004, while the opposite trend is found in degradation (Bartha, 2001(Bartha, , 2004. Based on these results, beta diversity is an appropriate indicator for detecting recovery (assembly) or degradation (disassembly) in vegetation.…”

Section: Discussionsupporting

confidence: 91%

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High resolution vegetation assessment with beta-diversity – a moving window approach

Bartha

Zimmermann²,

Horváth³

et al. 2011

JAI

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A B S T R A C TMonitoring designs are often suffering from the inherent non-stationarity of the monitored systems. To overcome this limitation, we propose a sampling design based on high resolution mapping and spatial analyses with double spatial scaling process. Applying to vegetation, we record the presence of plant species along 26 m or 52 m long belt transects of 520 (or 1040) units of 0.5 cm × 0.5 cm contiguous microquadrats. Beta diversity (represented as the diversity of species combinations) is estimated by subsequent computerised samplings from the baseline transect data sets. Beta diversity is scaled with changing resolutions across a range of scales from 5 cm × 5 cm to 5 cm × 500 cm., and it is also scaled using moving window technique. Local maximum of beta diversity is repeatedly calculated in 5 m extent observational windows shifted along the transect with 1 m lag, and the spatial variability of vegetation is visualized by the related beta-diversity profile. Using a field example, we demonstrate that beta diversity, when applied with our methodology, is a sensitive indicator, and it can reveal more information than alpha or gamma diversity. I N F O Ö S S Z E F O G L A L ÓKomplex rendszerek monitorozásánál tipikus nehézség a stacionaritás hiánya. A monitorozás tervezésekor gyakran megjósolhatatlanok a rendszer jövőbeni tulajdonságai és viselkedése. A probléma megoldására -a növényzet estében -nagy felbontású, egyedalapú térképezést javasolunk, majd az így nyert adatok többlépcsős, térsorozatokon alapuló számítógépes feldolgozását. A felvételezés során növényfajok jelenlétét rögzítjük mikrokvadrátokban. A részletes mintavétel 26 m vagy 52 m hosszú transszektek mentén történik, amelyek 5 × 5 cm-es mikrokvadrátok összefüggő sorozatából állnak (520 vagy 1040 db). A számítógépes feldolgozás során egy 5 m-es mintavételi ablak segítségével előbb elkülönítünk egy részmintát majd ezt növekvő mintavételi egységekkel megvizsgáljuk, és egy ún. lokális statisztikával (jelen esetben egyfajta béta-diverzitással) jellemezzük. A mintavételi ablakkal a transszektet az elejétől a végéig "letapogatva" egy diverzitási profilt nyerünk, amely bonyolult, nehezen kezelhető esetekben is (amikor a stacionaritási feltételek nem teljesülnek) jól jellemzi a növényzet állapotát. A módszer használatát egy terepi példa segítségével illusztráljuk, megmutatva, hogy a béta diverzitás más (alfa-és gamma-) diverzitásmértékeknél jobb indikátora a vegetáció változásainak.

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Section: Discussionsupporting

confidence: 91%

“…Beta diversity depends on spatial scale and on the abundance of species. The advantage of using Juhász-Nagy's models is the sigma additivity of models and the advanced methodology dealing with various aspects of scale dependence (Juhász-Nagy, 1980;Juhász-Nagy and Podani, 1983).…”

Section: Introductionmentioning

confidence: 99%

High resolution vegetation assessment with beta-diversity – a moving window approach

Bartha

Zimmermann²,

Horváth³

et al. 2011

JAI

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“…Starting from a homogeneous data set, the proposed case studies proved that the choice of the resolution scale affects the comprehension of the patterns of space occupancy and occurrence of the Habitats and the correlations between Habitats and environment (Greig-Smith, 1983;Juhász-Nagy & Podani, 1983;Reed, Peet, Palmer, & White, 1993), with a substantial relapse on the measurement of their AOO.…”

Section: Discussion: Lessons Learned and Perspectivesmentioning

confidence: 99%

Habitats on the grid: The spatial dimension does matter for red-listing

Gigante

Foggi

Venanzoni

et al. 2016

Journal for Nature Conservation

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a b s t r a c tBesides species Red Lists, recently, a variety of frameworks have been proposed for assessing higher levels of biological organisation, i.e. ecosystems, habitats, plant communities. Most of these protocols refer to 'plant species assemblages' or 'vegetation types' as proxies for ecosystems or habitats. Indeed, the habitat concept based on plant communities has acquired a central role as a key approach for biodiversity conservation above the species level. Plant communities, like every complex biological system, hold scaledependent 'emergent' properties which vary as a function of the scale of observation. With reference to red-listing, these scale-dependent properties have far-reaching consequences for both identification and classification, as well as for representation and evaluation, and become particularly challenging when dealing with criteria regarding decline in distribution or restricted distribution. The recent discussion on the red-listing protocols has evidenced several aspects that claim special efforts for a suitable use. In the present paper, starting with the analysis of some recently proposed protocols for the red-listing of habitats and ecosystems, we discuss and test some 'emergent' properties of species assemblages, providing cues for reflection. Based on a variety of theoretical models and scientific outcomes in literature from the last decades, we theorise that plant communities own some intrinsic, ecologically based and scale-dependent spatial features, which give rise to different types of pattern of spatial occupancy. We discuss a model where, in natural conditions, the possible patterns of spatial occupancy are referred to 3 basic types: areal, linear and point. This approach is here proposed as a tool to discriminate among different broad categories of plant community-based habitat types and optimise their assessment in the red-listing process. Starting from a homogeneous data set, the proposed case studies prove that the choice of the scale affects the comprehension of the habitats' occurrence, with a substantial relapse on the estimates of their distribution size. In particular, habitats with linear and point distribution, often naturally small in size and dispersed, are more susceptible to biased evaluation of their actual distribution and consequently of their threat status. The intrinsic spatial attributes of plant communities should not be neglected in a red-listing process and claim for a 'habitat-tailored' approach. The use of different gridcell sizes and thresholds for the three main patterns of spatial occupancy here proposed, might certainly avoid inaccurate statements.

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“…Therefore, we decided to use beta diversity for measuring the effect of yellow bluestem. Our preliminary studies showed that within-community patterns of species composition were good indicators of grassland succession and degradation [13,[30][31][32]. In addition to be a good indicator, beta diversity reflects important constraints of the spatial organization of vegetation [31,33,34].…”

Section: Introductionmentioning

confidence: 99%

Grazed Pannonian grassland beta-diversity changes due to C4 yellow bluestem

Szentes

Sutyinszki

Szabó³

et al. 2012

Open Life Sciences

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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.

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Information theory methods for the study of spatial processes and succession

Cited by 86 publications

References 20 publications

High resolution vegetation assessment with beta-diversity – a moving window approach

High resolution vegetation assessment with beta-diversity – a moving window approach

Habitats on the grid: The spatial dimension does matter for red-listing

Grazed Pannonian grassland beta-diversity changes due to C4 yellow bluestem

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