Georg Treffer

Trichophoreae is a nearly cosmopolitan Cyperaceae tribe that contains ∼17 species displaying striking variation in size, inflorescence complexity, and perianth morphology. Although morphologically distinct, the status of its three genera (Cypringlea, Oreobolopsis and Trichophorum) are controversial …

Background: The coincidence of long distance dispersal (LDD) and biome shift is assumed to be the result of a multifaceted interplay between geographical distance and ecological suitability of source and sink areas. Here, we test the influence of these factors on the dispersal history of the floweri…

The mid-Pliocene is a valuable time interval for investigating equilibrium climate at current atmospheric CO2 concentrations because atmospheric CO2 concentrations are thought to have been comparable to the current day and yet the climate and distribution of ecosystems were quite different. One intr…

Environmental change can create opportunities for increased rates of lineage diversification, but continued species accumulation has been hypothesized to lead to slowdowns via competitive exclusion and niche partitioning. Such density-dependent models imply tight linkages between diversification and…

Rhizopogon salebrosus is an ectomycorrhizal fungus native to North America and known in Europe. In this study we illustrate the worldwide biogeography of R. salebrosus based on sporocarp and ectomycorrhiza records. MaxEnt modelling was used to assess the distribution of the potential niche of R. salebrosus in Europe, based on climatic variables and the preferences of its ectomycorrhizal partner. At the beginning, R. salebrosus was only recorded in the mountainous regions (Alps and Elbe Mountains). In 2014 this fungus was recorded for the first time in Northern Poland and this is the first record of R. salebrosus in a lowland area. In Europe the most suitable habitats are in the western part of the Iberian Peninsula, British Isles, western edge of the Scandinavian Peninsula, Alps, Balkan and Carpathian Mountains and the Anatolian Peninsula. Considering climatic conditions the most important factor limiting the occurrence of R. salebrosus (with a 31.4% contribution) is precipitation in the coldest quarter. On the other hand, areas where the ectomycorrhizal partners of R. salebrosus occur, should be also considered as potential regions for its expansion in Europe.

One of the crucial choices when modelling species distributions using pseudo-absences approaches is the delineation of the background area to fit the model. We hypothesise that there is a minimum background area around the centre of the species distribution that characterizes well enough the range o…

Aim: To determine the global position of tree line isotherms, compare it with observed local tree limits on islands and mainlands, and disentangle the potential drivers of a difference between tree line and local tree limit. Location: Global. Time period: 1979–2013. Major taxa studied: Trees. Method…

Aim: Invasions are dynamic processes. Invasive spread causes the geographical range size of alien species to increase with residence time. However, with time native competitors and antagonists can adapt to invaders. This build‐up of biotic resistance may eventually limit the invader’s performance an…

Clonal plant species can produce genetically identical and potentially independent offspring, and dominate a variety of habitats. The divergent evolutionary mechanisms between clonal and non-clonal plants are interesting areas of ecological research. A number of studies have shown that the environme…

The ability to infer paleo-distributions with limited knowledge of absence makes species distribution modeling (SDM) a useful tool for exploring paleobiogeographic questions. Spatial sampling bias is a known issue when modeling extant species. Here we quantify the spatial sampling bias in a North Am…