Biology subjects

Trutschnig, W.

Publications and source records attributed to Trutschnig, W..

4 recordsLinked to original sources

bioRxiv2025

Future Range Shifts and Diversity Patterns of Antarctic Lecideoid Lichens Under Climate Change Scenarios

Being uniquely adapted to extreme environmental conditions, rock-dwelling lecideoid lichens are a diverse and major component of terrestrial vegetation in Antarctica. Climate change is reshaping Antarctic ecosystems, forcing cold-adapted species to migrate to maintain their climatic niche. The study surveyed the circum Antarctic lecideoid lichen diversity and modelled the impacts of two climate change scenarios on their distributional range shifts across Antarctica. Myco- and photobiont symbionts of lecideoid lichen species from a circum-Antarctic sampling were classified using classical barcoding methods. The climatic niches of nine common mycobiont species and four photobiont OTUs were modelled, and range shifts were projected across four Antarctic bioregions under two Shared Socioeconomic Pathways: (a) SSP1-2.6: sustainable development (2.6 Wm-2, +3{degrees}C) and (b) SSP5-8.5: continued dependence on fossil fuels (8.5 Wm-2, +5.1{degrees}C). DNA barcoding revealed altogether 34 species of lecideoid lichens and 9 photobiont OTUs for the Antarctic continent. In addition to the already known lichen species in Antarctica, three newly detected species of the genus Lecidella could be identified. The calculated climate change scenarios across bioregions predict greater range expansion for mycobiont species and photobiont OTUs than climate-induced habitat loss. While niche contraction is expected in maritime Antarctica, species distributions are expected to expand in continental regions, primarily due to inland shifts. These inland areas may serve as emerging climatic refugia for certain mycobiont species. Overall, these results suggest that, under future warming, lecideoid lichens undergo an overall range expansion, particularly in previously uncolonized inland areas in continental Antarctica.

ecology↗

bioRxiv2022

qad: An R-package to detect asymmetric and directed dependence in bivariate samples

Correlations belong to the standard repertoire of ecologists for quantifying the strength of dependence between two random variables. Classical dependence measures are usually not capable of detecting non-monotonic or non-functional dependencies. Furthermore, they completely fail to detect asymmetry and direction in dependence, which exist in many situations and should not be ignored. In this paper, we present qad (short for quantification of asymmetric dependence), a non-parametric statistical method to quantify directed and asymmetric dependence of bivariate samples. qad is applicable in general situations, is sensitive to noise in data, exhibits a good small sample performance, detects asymmetry in dependence, shows high power in testing for independence, requires no assumptions regarding the underlying distribution of the data, and reliably quantifies the information gain/predictability of quantity Y given knowledge of quantity X, and vice versa (i.e. q(X,Y) = q(Y, X)). Here, we briefly recall the methodology underlying qad, introduce the functions of the R-package qad, which returns estimates for the measures q(X, Y) denoting the directed dependence of Y on X (or, equivalently, the influence of X on Y), q(Y, X) the directed dependence of X on Y, a(X, Y) [colone] q(X, Y) - q(Y, X) the asymmetry in dependence. Furthermore, qad can be used to predict Y given knowledge of X, and vice versa. Additionally, we compare empirical performance of qad with that of seven other well established measures and demonstrate the applicability of qad on ecological datasets. We illustrate that direction and asymmetry in dependence are universal properties of bivariate associations. qad thus provides additional information gain and the avoidance of model bias and will therefore advance and facilitate the understanding of ecological systems.

ecology↗

bioRxiv2021

Floral scents of a deceptive plant are hyperdiverse and under population-specific phenotypic selection

Floral scent is a key mediator in plant-pollinator interactions; however, little is known to what extent intraspecific scent variation is shaped by phenotypic selection, with no information yet in deceptive plants. We recorded 291 scent compounds in deceptive moth fly-pollinated Arum maculatum from various populations north vs. south of the Alps, the highest number so far reported in a single plant species. Scent and fruit set differed between regions, and some, but not all differences in scent could be explained by differential phenotypic selection in northern vs. southern populations. Our study is the first to provide evidence that phenotypic selection is involved in shaping geographic patterns of floral scent in deceptive plants. The hyperdiverse scent of A. maculatum might result from the plants imitation of various brood substrates of its pollinators.

ecology↗

bioRxiv2019

Myco- and photobiont associations in crustose lichens in the McMurdo Dry Valleys (Antarctica) reveal high differentiation along an elevational gradient

The climate conditions of the McMurdo Dry Valleys (78{degrees} S) are characterized by low temperatures and low precipitation. The annual temperatures at the valley bottoms have a mean range from -30 {degrees}C to -15 {degrees}C and decrease with elevation. Precipitation occurs mostly in form of snow (3-50 mm a-1 water equivalent) and, liquid water is rare across much of the landscape for most of the year and represents the primary limitation to biological activity. Snow delivered off the polar plateau by drainage winds, dew and humidity provided by clouds and fog are important water sources for rock inhibiting crustose lichens. In addition, the combination of the extremely low humidity and drying caused by foehn winds, confined to lower areas of the valleys, with colder and moister air at higher altitudes creates a strongly improving water availability gradient with elevation.\n\nWe investigated the diversity and interaction specificity of myco-/photobiont associations of a total of 232 crustose lichen specimens, collected along an elevational gradient (171-959 m a.s.l.) within the McMurdo Dry Valleys with regard to the spatial distribution caused by climatological and geographical factors. For the identification of the mycobiont and photobiont species three markers each were amplified (nrITS, mtSSU, RPB1 and nrITS, psbJ-L, COX2, respectivley). Elevation, associated with a water availability gradient, turned out to be the key factor explaining most of the distribution patterns of the mycobionts. Pairwise comparisons showed Lecidea cancriformis and Rhizoplaca macleanii to be significantly more common at higher, and Carbonea vorticosa and Lecidea polypycnidophora at lower, elevations. Lichen photobionts were dominated by the globally distributed Trebouxia OTU, Tr_A02 which occurred at all habitats. Network specialization resulting from mycobiont-photobiont bipartite network structure varied with elevation and associated abiotic factors.\n\nAlong an elevational gradient, the spatial distribution, diversity and genetic variability of the lichen symbionts appear to be mainly influenced by improved water relations at higher altitudes.

ecology↗