Landscapes Forest and Global Change - ESA - Escola Superior ...

E.W Saragih et al. 2010. Effects of endozoochorous seed dispersal on the soil seed bank and vegetation in the woodland area
163
ungrazed area. This might indicate contribution of large herbivore on the establishment of lawn
species.
4.3 The contribution of endozoochous seed dispersal to the soil seed bank
The seed density in ungrazed woodland are is higher than in grazed woodland. The expectation
was in contrast because cattle contribute the number of seeds into the grazed area. One reason
for the higher number of seed in ungrazed soil could be the thickness of litter layer. The litter
layer in the ungrazed (36 cm) area is thicker than in the grazed area (30.5 cm). Litter increased
seed longevity (Rotundo and Aguiar 2005) and when the litter layer is thick, this can lead to the
conservation of seed in the soil (Jensen 1998). Furthermore, trampling by cattle can bury seeds
deeply so they were not present in the top soil samples (30 cm deep). McDonald et al. 1996
stated that grazing allows the incorporation of seeds deeply in the soil. Twelve species of
summer dung sample absent from soil seed bank ungrazed and grazed woodland area. The
summer dung species needed more light (L Ellenberg’s value >6) and have the same
requirement levels of moisture and nitrogen. Winter dung might contribute more to the species
richness of the soil seed bank than the summer dung did. This could be the case as during the
winter, limited foods were available for the cattle which led them to consume more different
plants species. On the contrary in the summer, the cattle preferred the most palatable
species, mostly grasses which were abundant during this season. Grass species have a
low seed longevity index and low densities in the soil. Total seed density of lawn
species was higher in soil seed bank ungrazed area than grazed area, however total
frequency of lawn species in soil seed bank grazed area is higher than ungrazed. This
might indicate role of cattle on distribution of lawn species which showed by more lawn
species was found in soil seed bank grazed area than ungrazed area. Jasione montana,
Lamium purpureum & Sonchus oleraceus dispersed by cattle during the winter and only
found in soil seed bank grazed area.
References
Bakker, C., H. F. d. Graaf, W. H. O. Ernst, and P. M. v. Bodegom. 2005. Does the seed bank
contribute to the restoration of species-rich vegetation in wet dune slacks Applied
Vegetation Science. 2005; 8:39-48.
Bakker, E. E. S., and H. H. Olff. 2003. Impact of different-sized herbivores on recruitment
opportunities for subordinate herbs in grasslands. Journal Of Vegetation Science 14:465.
Bokdam, J., and J. M. Gleichman. 2000. Effects of grazing by free-ranging cattle on vegetation
dynamics in a continental north-west European heathland. Journal Of Applied Ecology
37:415-431.
Bokdam, J. S. 2003. Nature conservation and grazing management: free-ranging cattle as a
driving force for cyclic vegetation succession, Wageningen. The Netherlands.
Cosyns, E., A. Delporte, L. Lens, and M. Hoffmann. 2005a. Germination success of temperate
grassland species after passage through ungulate and rabbit guts. Journal Of Ecology
93:353-361.
Cosyns, E. E., S. S. Claerbout, I. I. Lamoot, and M. M. Hoffmann. 2005b. Endozoochorous seed
dispersal by cattle and horse in a spatially heterogeneous landscape. Plant ecology
178:149.
Couvreur, M., E. Cosyns, M. Hermy, and M. Hoffmann. 2005. Complementarity of epi- and
endozoochory of plant seeds by free ranging donkeys. Ecography 28:37-48.
Dai, X. 2000. Impact of cattle dung deposition on the distribution pattern of plant species in an
alvar limestone grassland. Journal Of Vegetation Science 11:715.
Falinska, K. 1998. Long-term changes in size and composition of seed bank during succession:
From meadow to forest. Acta Societatis Botanicorum Poloniae 67:301.
Haskell, J. P., M. E. Ritchie, and H. Olff. 2002. Fractal geometry predicts varying body size
scaling relationships for mammal and bird home ranges. Nature 418:527-530.
Forest Landscapes and Global Change-New Frontiers in Management, Conservation and Restoration. Proceedings of the IUFRO Landscape Ecology
Working Group International Conference, September 21-27, 2010, Bragança, Portugal. J.C. Azevedo, M. Feliciano, J. Castro & M.A. Pinto (eds.)
2010, Instituto Politécnico de Bragança, Bragança, Portugal.