10.5061/DRYAD.J182Q
Fedriani, José M.
Helmholtz Centre for Environmental Research
University of Lisbon
Wiegand, Thorsten
Helmholtz Centre for Environmental Research
Calvo, Gemma
University of Alberta
Suárez-Esteban, Alberto
University of Alberta
Yukon College
Jácome, Miguel
Estación Biológica de Doñana
Żywiec, Magdalena
Polish Academy of Sciences
Delibes, Miguel
Estación Biológica de Doñana
Data from: Unraveling conflicting density- and distance-dependent effects
on plant reproduction using a spatially-explicit approach
Dryad
dataset
2016
distance dependence
Pistacia lentiscus
Chamaerops humilis
population regulation
Pyrus bourgaeana
conflicting effects
2016-07-06T00:00:00Z
2016-07-06T00:00:00Z
en
https://doi.org/10.1111/1365-2745.12454
69394 bytes
1
CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
1. Density- and distance-dependent (DDD) mechanisms are important
determinants of plant reproductive success (PRS). Different components of
sequential PRS can operate either in the same or in different directions
and thus reinforce or neutralize each other, and they may also operate at
different spatial scales. Thus, spatially-explicit approaches are needed
to detect such complex DDD effects across multiple PRS components and
spatial scales. 2. To reveal DDD effects of different components of early
PRS of the Iberian pear (Pyrus bourgaeana) sampled over three consecutive
years, we used marked point pattern analysis. Our special interest is to
identify conflicting processes that regulate populations at different
spatial scales, e.g. whether DDD on fruit initiation and on fruit
development acted in opposite directions. To evaluate the significance of
observed mark correlation functions based on empirical data (e.g. fruiting
success) we compared them to expectations given by spatially-explicit null
models. 3. Diverse DDD processes affected several aspects of PRS in a
variable extent over the three seasons. First, early fruit set was higher
for individuals with more neighbors at small distances (i.e. up to 40m).
However, late P. bourgaeana fruit set decreased with increasing number of
nearby neighbors, but these effects canceled for overall fruit set that
did not show DDD effects. Second, the absolute number of fruits produced
(crop sizes) by trees showed positive density dependence in 2011 and 2012
but not in 2013. Finally, the total number of seeds produced did not show
DDD effects, indicating that conflicting demographic processes can disrupt
the initial spatial pattern of tree investment in reproduction. 4.
Synthesis: Understanding complex spatial effects of density- and
distance-dependent (DDD) processes requires dissection of component
processes to attain the complete picture since contrasting DDD processes
may be hidden behind a single cumulative measure of reproductive success.
The combination of novel and classic mark correlation functions used here
constitute a powerful spatially-explicit tool that can be broadly applied
to unravel conflicting mechanisms of DDD regulating the persistence of
sessile organisms at a range of spatial scales. Our findings help to
explain why some authors failed to find expected DDD of PRS and highlight
the importance of detailed multi-year field studies on plant reproductive
success.
crop sizesThis file contains data concerning tree location and crop size
during 2011, 2012, and 2013.fruit initiationThis file contains data
concerning tree locations and fruit initiation successes during 2012 and
2013.fruit developmentThis files contains data concerning tree locations
and fruiting development successes during 2011, 2012, and 2013.seed set
2011This file contains data on tree locations and total seed number per
tree during 2011.
Mediterranean basin
Doñana National Park
Spain