TY  - JOUR
A1  - Gemeinholzer, B.
A1  - May, F.
A1  - Ristow, Michael
A1  - Batsch, C.
A1  - Lauterbach, D.
T1  - Strong genetic differentiation on a fragmentation gradient among populations of the heterocarpic annual Catananche lutea L. (Asteraceae)
JF  - Plant systematics and evolution
N2  - In landscapes which are predominately characterised by agriculture, natural ecosystems are often reduced to a mosaic of scattered patches of natural vegetation. Species with formerly connected distribution ranges now have restricted gene flow among populations. This has isolating effects upon population structure, because species are often confined by their limited dispersal capabilities. In this study, we test the effects of habitat fragmentation, precipitation, and isolation of populations on the genetic structure (AFLP) and fitness of the Asteraceae Catananche lutea. Our study area is an agro-dominated ecosystem in the desert-Mediterranean transition zone of the Southern Judea Lowlands in Israel. Our analysis revealed an intermediate level of intra-population genetic diversity across the study site with reduced genetic diversity on smaller scale. Although the size of the whole study area was relatively small (20 x 45 km), we found isolation by distance to be effective. We detected a high level of genetic differentiation among populations but genetic structure did not reflect spatial patterns. Population genetic diversity was correlated neither with position along the precipitation gradient nor with different seed types or other plant fitness variables in C. lutea.
KW  - AFLP
KW  - Heterocarpy
KW  - Population structure
KW  - Precipitation gradient
KW  - Asteraceae
Y1  - 2012
U6  - https://doi.org/10.1007/s00606-012-0661-1
SN  - 0378-2697
VL  - 298
IS  - 8
SP  - 1585
EP  - 1596
PB  - Springer
CY  - Wien
ER  - 
TY  - JOUR
A1  - Lauterbach, D.
A1  - Roemermann, C.
A1  - Jeltsch, Florian
A1  - Ristow, Michael
T1  - Factors driving plant rarity in dry grasslands on different spatial
 scales: a functional trait approach
JF  - BIODIVERSITY AND CONSERVATION
N2  - In European dry grasslands land-use changes affect plant species performance and frequency. Potential driving forces are eutrophication and habitat fragmentation. The importance of these factors is presumably scale dependent. We used a functional trait approach to detect processes that influence species frequency and endangerment on different spatial scales. We tested for associations between functional traits and (1) frequency and (2) degree of endangerment on local, regional and national scales. We focussed on five selected traits that describe the life-history of plant species and that are related to competition, dispersal ability and habitat specificity. Trait data on plant height, SLA, plant coverage, peak of flowering and diaspore mass were measured for 28 perennials from common to rare and endangered to non-endangered on 59 dry grassland sites in north-eastern Germany. Multiple regression models revealed that species frequency is positively and species endangerment negatively related to plant height, plant coverage and SLA on more than one spatial scale. On the local scale, diaspore mass has a negative effect on species frequency. More frequent and less endangered species show a later peak of flowering on nationwide and regional scales. We concluded that competition traits are more important on larger scales, whereas dispersal traits are more important for species frequency on the smaller scale. On national and regional scales, eutrophication and habitat loss may be the main drivers of species threat, whereas on the local scale fragmentation plays a crucial role for the performance of dry grassland species.
KW  - Species frequency
KW  - Species endangerment
KW  - Fragmentation
KW  - Eutrophication
KW  - SLA
Y1  - 2013
U6  - https://doi.org/10.1007/s10531-013-0455-y
SN  - 0960-3115
VL  - 22
IS  - 10
SP  - 2337
EP  - 2352
PB  - SPRINGER
CY  - DORDRECHT
ER  -