A spatially explicit analysis of seedling recruitment in the terrestrial orchid Orchis purpurea.
Seed dispersal and the subsequent recruitment of new individuals into a population are important processes affecting the population dynamics, genetic diversity and spatial genetic structure of plant populations. Spatial patterns of seedling recruitment were investigated in two populations of the terrestrial orchid Orchis purpurea using both univariate and bivariate point pattern analysis, parentage analysis and seed germination experiments. Both adults and recruits showed a clustered spatial distribution with cluster radii of c. 4-5 m. The parentage analysis resulted in offspring-dispersal distances that were slightly larger than distances obtained from the point pattern analyses. The suitability of microsites for germination differed among sites, with strong constraints in one site and almost no constraints in the other. These results provide a clear and coherent picture of recruitment patterns in a tuberous, perennial orchid. Seed dispersal is limited to a few metres from the mother plant, whereas the availability of suitable germination conditions may vary strongly from one site to the next. Because of a time lag of 3-4 yr between seed dispersal and actual recruitment, and irregular flowering and fruiting patterns of adult plants, interpretation of recruitment patterns using point patterns analyses ideally should take into account the demographic properties of orchid populations.
Jacquemyn
Hans
H
Division of Forest, Nature and Landscape Research, Catholic University of Leuven, Celestijnenlaan 200E, B-3001 Leuven, Belgium.
Brys
Rein
R
Division of Forest, Nature and Landscape Research, Catholic University of Leuven, Celestijnenlaan 200E, B-3001 Leuven, Belgium.
Vandepitte
Katrien
K
Applied Genetics and Breeding, Institute for Agricultural and Fisheries Research, Caritasstraat 21, 9090 Melle, Belgium.|Laboratory of Plant Ecology, Catholic University of Leuven, Arenbergpark 31, B-3001 Heverlee, Belgium.
Honnay
Olivier
O
Laboratory of Plant Ecology, Catholic University of Leuven, Arenbergpark 31, B-3001 Heverlee, Belgium.
Roldán-Ruiz
Isabel
I
Applied Genetics and Breeding, Institute for Agricultural and Fisheries Research, Caritasstraat 21, 9090 Melle, Belgium.
Wiegand
Thorsten
T
Department of Ecological Modelling, UFZ Helmholtz Centre for Environmental Research, PF 500136, DE-04301 Leipzig, Germany.
D000704:Analysis of Variance; D005819:Genetic Markers; D018525:Germination; D029595:Orchidaceae / Q000196:embryology* / Q000235:genetics / Q000382:microbiology; D011110:Polymorphism, Genetic; D011156:Population Density; D011157:Population Dynamics; D036226:Seedlings / Q000235:genetics / Q000254:growth & development / Q000502:physiology*; D012639:Seeds / Q000254:growth & development / Q000382:microbiology / Q000502:physiology*
D005819:Genetic Markers