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Plant phenology or life-history patterns change seasonally as plants grow, mature, flower, and produce fruit and seed. Plant phenology follows seasonal patterns, yet variation may occur due to annual differences in the timing of rainfall and ambient temperature shifts. Foliage growth, flower, fruit, and seed production are important aspects of plant population dynamics and food resource availability for animals. The purpose of this study is to assess phenological patterns of plants across a series of biotic communities that represent an environmental moisture gradient. These communities all in the Chihuahuan Desert include: creosote bush shrubland, black grama grassland, and blue grama grassland. Plant phenology is recorded for all plant species across 4 replicate 200 m transects at each of the 3 habitat sites. Plant phenology measurements are taken once every month from February through October. The first ten individuals (or ten representative individuals) of each plant species encountered along each transect are assessed for life-history status. Data from the site P and J were only collected in 2000 and 2001 and are included in this data set.
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Temporal variability and predictability predict alpine plant community composition and distribution patterns
Abstract One of the most reliable features of natural systems is that they change through time. Theory predicts that temporally fluctuating conditions shape community composition, species distribution patterns, and life history variation, yet features of temporal variability are rarely incorporated into studies of species–environment associations. In this study, we evaluated how two components of temporal environmental variation—variability and predictability—impact plant community composition and species distribution patterns in the alpine tundra of the Southern Rocky Mountains in Colorado (USA). Using the Sensor Network Array at the Niwot Ridge Long‐Term Ecological Research site, we used in situ, high‐resolution temporal measurements of soil moisture and temperature from 13 locations (“nodes”) distributed throughout an alpine catchment to characterize the annual mean, variability, and predictability in these variables in each of four consecutive years. We combined these data with annual vegetation surveys at each node to evaluate whether variability over short (within‐day) and seasonal (2‐ to 4‐month) timescales could predict patterns in plant community composition, species distributions, and species abundances better than models that considered average annual conditions alone. We found that metrics for variability and predictability in soil moisture and soil temperature, at both daily and seasonal timescales, improved our ability to explain spatial variation in alpine plant community composition. Daily variability in soil moisture and temperature, along with seasonal predictability in soil moisture, was particularly important in predicting community composition and species occurrences. These results indicate that the magnitude and patterns of fluctuations in soil moisture and temperature are important predictors of community composition and plant distribution patterns in alpine plant communities. More broadly, these results highlight that components of temporal change provide important niche axes that can partition species with different growth and life history strategies along environmental gradients in heterogeneous landscapes.
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- PAR ID:
- 10556410
- Publisher / Repository:
- The Ecological Society of America
- Date Published:
- Journal Name:
- Ecology
- ISSN:
- 0012-9658
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Plant phenology or life-history patterns change seasonally as plants grow, mature, flower, and produce fruit and seed. Plant phenology follows seasonal patterns, yet variation may occur due to annual differences in the timing of rainfall and ambient temperature shifts. Foliage growth, flower, fruit, and seed production are important aspects of plant population dynamics and food resource availability for animals. The purpose of this study is to assess phenological patterns of plants across a series of biotic communities that represent an environmental moisture gradient. These communities all in the Chihuahuan Desert include: creosote bush shrubland, black grama grassland, and blue grama grassland. Plant phenology is recorded for all plant species across 4 replicate 200 m transects at each of the 3 habitat sites. Plant phenology measurements are taken once every month from February through October. The first ten individuals (or ten representative individuals) of each plant species encountered along each transect are assessed for life-history status. Data from the site P and J were only collected in 2000 and 2001 and are included in this data set.more » « less
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Abstract This study integrated spatially distributed field observations and soil thermal models to constrain the impact of frozen ground on snowmelt partitioning and streamflow generation in an alpine catchment within the Niwot Ridge Long‐Term Ecological Research site, Colorado, USA. The study area was comprised of two contrasting hillslopes with notable differences in topography, snow depth and plant community composition. Time‐lapse electrical resistivity surveys and soil thermal models enabled extension of discrete soil moisture and temperature measurements to incorporate landscape variability at scales and depths not possible with point measurements alone. Specifically, heterogenous snowpack thickness (~0–4 m) and soil volumetric water content between hillslopes (~0.1–0.45) strongly influenced the depths of seasonal frost, and the antecedent soil moisture available to form pore ice prior to freezing. Variable frost depths and antecedent soil moisture conditions were expected to create a patchwork of differing snowmelt infiltration rates and flowpaths. However, spikes in soil temperature and volumetric water content, as well as decreases in subsurface electrical resistivity revealed snowmelt infiltration across both hillslopes that coincided with initial decreases in snow water equivalent and early increases in streamflow. Soil temperature, soil moisture and electrical resistivity data from both wet and dry hillslopes showed that initial increases in streamflow occurred prior to deep soil water flux. Temporal lags between snowmelt infiltration and deeper percolation suggested that the lateral movement of water through the unsaturated zone was an important driver of early streamflow generation. These findings provide the type of process‐based information needed to bridge gaps in scale and populate physically based cryohydrologic models to investigate subsurface hydrology and biogeochemical transport in soils that freeze seasonally.more » « less
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1002/ecy.4450
