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Why are small seeds dispersed through animal guts: large numbers or seed size per se?

Bruun, Hans Henrik LU and Poschlod, Peter (2006) In Oikos 113(3). p.402-411
Abstract
Long-distance dispersal of seeds is an important process in metapopulation dynamics and in plant migrations, but at the same time extremely difficult to observe or quantify directly. If seed dispersal ability were related to attributes of seeds or motherplants, long-distance seed dispersal would be predictable by indirect approximation using easy-to-measure traits. Seed size has been suggested to be such a key trait in seed dispersal ability. However, having smaller seeds also implies having more numerous seeds per plant individual (given equal reproductive effort), and consequently increases the probability of seeds being ingested accidentally. The question is whether small-seeded species are more abundant in herbivore dung because... (More)
Long-distance dispersal of seeds is an important process in metapopulation dynamics and in plant migrations, but at the same time extremely difficult to observe or quantify directly. If seed dispersal ability were related to attributes of seeds or motherplants, long-distance seed dispersal would be predictable by indirect approximation using easy-to-measure traits. Seed size has been suggested to be such a key trait in seed dispersal ability. However, having smaller seeds also implies having more numerous seeds per plant individual (given equal reproductive effort), and consequently increases the probability of seeds being ingested accidentally. The question is whether small-seeded species are more abundant in herbivore dung because smaller seed size increases survival rate during gut passage or because they are produced (and ingested) in greater numbers than larger seeds. We investigated endozoochorous seed dispersal via cattle grazing a meadow, and related seed abundance in dung samples to seed attributes. We found that seeds were ingested and passed through the bovine intestinal tract in proportion to the numbers produced per unit area in the grazed vegetation. In contrast, no relationship could be found between endozoochorous dispersal potential (measured as abundance of seeds in dung samples corrected for seed output in the grazed vegetation) and seed attributes such as seed mass, seed shape (roundness), and thickness of the seed coat. This finding underlines the importance of seed number in plant dispersal ability. In addition, it shows that grazing mammals may constitute an important dispersal vector for many plant species conventionally classified as 'unspecialised'. (Less)
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author
and
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Oikos
volume
113
issue
3
pages
402 - 411
publisher
Wiley-Blackwell
external identifiers
  • wos:000238103800003
  • scopus:33745027640
ISSN
1600-0706
DOI
10.1111/j.2006.0030-1299.14114.x
language
English
LU publication?
yes
additional info
The information about affiliations in this record was updated in December 2015. The record was previously connected to the following departments: Plant Ecology and Systematics (Closed 2011) (011004000)
id
eccc6508-a50e-443b-bf2a-ab400288c595 (old id 159632)
date added to LUP
2016-04-01 11:51:08
date last changed
2020-12-22 03:40:31
@article{eccc6508-a50e-443b-bf2a-ab400288c595,
  abstract     = {Long-distance dispersal of seeds is an important process in metapopulation dynamics and in plant migrations, but at the same time extremely difficult to observe or quantify directly. If seed dispersal ability were related to attributes of seeds or motherplants, long-distance seed dispersal would be predictable by indirect approximation using easy-to-measure traits. Seed size has been suggested to be such a key trait in seed dispersal ability. However, having smaller seeds also implies having more numerous seeds per plant individual (given equal reproductive effort), and consequently increases the probability of seeds being ingested accidentally. The question is whether small-seeded species are more abundant in herbivore dung because smaller seed size increases survival rate during gut passage or because they are produced (and ingested) in greater numbers than larger seeds. We investigated endozoochorous seed dispersal via cattle grazing a meadow, and related seed abundance in dung samples to seed attributes. We found that seeds were ingested and passed through the bovine intestinal tract in proportion to the numbers produced per unit area in the grazed vegetation. In contrast, no relationship could be found between endozoochorous dispersal potential (measured as abundance of seeds in dung samples corrected for seed output in the grazed vegetation) and seed attributes such as seed mass, seed shape (roundness), and thickness of the seed coat. This finding underlines the importance of seed number in plant dispersal ability. In addition, it shows that grazing mammals may constitute an important dispersal vector for many plant species conventionally classified as 'unspecialised'.},
  author       = {Bruun, Hans Henrik and Poschlod, Peter},
  issn         = {1600-0706},
  language     = {eng},
  number       = {3},
  pages        = {402--411},
  publisher    = {Wiley-Blackwell},
  series       = {Oikos},
  title        = {Why are small seeds dispersed through animal guts: large numbers or seed size per se?},
  url          = {http://dx.doi.org/10.1111/j.2006.0030-1299.14114.x},
  doi          = {10.1111/j.2006.0030-1299.14114.x},
  volume       = {113},
  year         = {2006},
}