Revista Chilena de Historia Natural 83 (3): 375-386, 2010
RESEARCH ARTICLE
Misodendrum punctulatum (Misodendraceae) seed dispersal and colonization
patterns on a Nothofagus antarctica (Nothofagaceae) post-fire shrubland from Northwestern Patagonia
Spatial dispersal pattern could determine the spatial pattern of establishment affecting the
vegetation structure. Our work, analyze dispersion and colonization attribute of the hemiparasitic plant Misodendrum
punctulatum (Misodendraceae). Our hypothesis outline that the wind dispersal pattern of M. punctulatum seeds
determine the infection pattern (colonization) on Nothofagus antarctica, and both processes (dispersion and colonization)
are asymmetric in accordance with the predominant wind direction. This study was carry out in a N. Antarctica (host)
post-fire shrubland. We assessed the seed dispersal estimating number of seed on host branches supplied from infected-survivals
hosts (focal host) toward each cardinal direction. Colonization was assessed estimating number of infections on each host, through
transects, at every cardinal direction from the focal host. We observed that seeds dispersed decline with distances from the seed
source, and dispersion fitted to a negative exponential model. The longest distance of primary dispersion observed was 10 m toward
east. About colonization, longest distance from the focal host was 22.5 m toward south. Furthermore, ratio of infected host was lesser
on west, one infected by 10 uninfected (1:10) than other compass aspects (1:6). Both process, dispersion and colonization, showed a
similar and asymmetric pattern of distribution, which could be result of wind direction predominant from northwest. In addition, a high
spatial correlation was observed among number of seed dispersed and recruitment of infection in distances from the sources of
seeds. Our results allow understand the patterns of spatial distribution and infection dynamics of Misodendrum
punctulatum. In order to plan management strategies, understanding the infection dynamics is useful to perform successfully
strategies to the control of hemiparasitic plants in forest to commercial use, and conservation or restoration strategies, e.g. to restorate
this hemiparasitic specie in areas recently colonized by N. antarctica. These studied aspects in Misodendrum
punctulatum contribute to the knowledge of this ecological interaction, which is frequent in Nothofagus forests from
Argentina and Chile.
Key words:
dynamics, host,
parasitism, succession, wind dispersion
