10.5061/DRYAD.R4XGXD29R
Liang, Maowei
0000-0002-1517-0497
Peking University
Feng, Xiao
University of Arizona
Gornish, Elise
0000-0002-2055-4874
University of Arizona
Rainfall pulses mediate long-term plant community compositional dynamics
in a semi-arid rangeland
Dryad
dataset
2020
Ecology
2020-09-23T00:00:00Z
2020-09-23T00:00:00Z
en
https://cals.arizona.edu/srer/data.html
178729 bytes
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CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
1. Semi-arid rangelands, comprising more than 40% of the Earth’s land
surface, provide critical ecosystem services. Worldwide, these ecosystems
are experiencing rapid degradation due to overgrazing and precipitation
changes. However, how plants respond to these interacting factors remains
relatively unexplored, and precisely which and how rainfall factors
determine plant community dynamics in rangelands has not been well
developed. 2. We used a long-term (1953‒2018) dataset from semi-arid
rangeland to investigate coupled effects of grazing intensity and rainfall
intensity (the total amount of precipitation) on different groups of plant
cover (herbaceous, woody, and cacti plants) using linear mixed-effects
models, redundancy analysis and structural equation models. We examined
how rainfall intensity influenced plant cover dynamics according to pulse
size (intensity over time) categories, which we analyzed at three scales:
yearly, within the wet season only (June to September), and within the dry
season only (October to May). 3. Plant community cover showed a
humpbacked trend in the last six decades, mostly through changes in woody
plants. Although both grazing intensity and rainfall presented similar
humpbacked trends with plant community cover, our models demonstrated that
the reduction of plant cover from the 1990s has been mainly caused by a
decrease of rainfall rather than grazing intensity, particularly due to
profound reductions of the intensity of relatively small rainfall pulses
(e.g., 5.1 ~ 15 mm·day-1) during the dry season. Specifically, these small
rainfall pulses can increase plant cover of all subgroups of woody and
herbaceous species, thereby increasing plant community cover. Moreover,
rainfall pulses during the wet season had negative effects on herbaceous
species and positive effects on woody plants. These results suggest a
phenological niche partitioning between woody plants and herbaceous in
subtropical rangelands. 4. Synthesis and applications. Our results show
how critical seasonal rainfall pulses are for regulating plant community
compositional dynamics, which has significant implications for rangeland
management and our ability to adapt and mitigate amplified climate
influences in semi-arid ecosystems.
The data has been used in this study were originally derived from the
dataset from the Santa Rita Experimental Range
(https://cals.arizona.edu/srer/). The descriptions of data collections can
be found in the sub-data files, which is called "Long term vegetation
transects, precipitation, maps, photos, and bibliography"
(https://cals.arizona.edu/srer/data.html).