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Hotspots of Community Change: Temporal Dynamics Are Spatially Variable in Understory Plant Composition of a California Oak Woodland.

Spotswood EN, Bartolome JW, Allen-Diaz B - PLoS ONE (2015)

Bottom Line: Temporal dynamics are often assumed to be relatively static at the landscape scale, provided disturbance and climate are continuous.This study shows that local and landscape scale factors jointly influence temporal dynamics creating hotspots that are particularly responsive to climate and disturbance.Thus, adequate predictions of response to disturbance or to changing climate will only be achieved by considering how factors at multiple spatial scales influence community resilience and recovery.

View Article: PubMed Central - PubMed

Affiliation: Department of Environmental Science, Policy and Management, University of California, Berkeley, California, United States of America.

ABSTRACT
Community response to external drivers such climate and disturbance can lead to fluctuations in community composition, or to directional change. Temporal dynamics can be influenced by a combination of drivers operating at multiple spatial scales, including external landscape scale drivers, local abiotic conditions, and local species pools. We hypothesized that spatial variation in these factors can create heterogeneity in temporal dynamics within landscapes. We used understory plant species composition from an 11 year dataset from a California oak woodland to compare plots where disturbance was experimentally manipulated with the removal of livestock grazing and a prescribed burn. We quantified three properties of temporal variation: compositional change (reflecting the appearance and disappearance of species), temporal fluctuation, and directional change. Directional change was related most strongly to disturbance type, and was highest at plots where grazing was removed during the study. Temporal fluctuations, compositional change, and directional change were all related to intrinsic abiotic factors, suggesting that some locations are more responsive to external drivers than others. Temporal fluctuations and compositional change were linked to local functional composition, indicating that environmental filters can create subsets of the local species pool that do not respond in the same way to external drivers. Temporal dynamics are often assumed to be relatively static at the landscape scale, provided disturbance and climate are continuous. This study shows that local and landscape scale factors jointly influence temporal dynamics creating hotspots that are particularly responsive to climate and disturbance. Thus, adequate predictions of response to disturbance or to changing climate will only be achieved by considering how factors at multiple spatial scales influence community resilience and recovery.

No MeSH data available.


Related in: MedlinePlus

Temporal fluctuation and functional composition.Relationships between temporal fluctuation and functional composition (perennial cover %)during the pre-treatment period between 1998 and 2001 when a fence was installed to exclude grazing from one experimental watershed. Temporal fluctuation is quantified as the root mean square of the residuals from the linear regression line relating time lag to Bray-Curtis dissimilarity in species composition, calculated at the plot level.
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pone.0133501.g005: Temporal fluctuation and functional composition.Relationships between temporal fluctuation and functional composition (perennial cover %)during the pre-treatment period between 1998 and 2001 when a fence was installed to exclude grazing from one experimental watershed. Temporal fluctuation is quantified as the root mean square of the residuals from the linear regression line relating time lag to Bray-Curtis dissimilarity in species composition, calculated at the plot level.

Mentions: Both directional change and temporal fluctuations were related to disturbance type (Fig 4). Directional changes were most pronounced on plots where grazing was removed, and fluctuations were least pronounced on plots where disturbance regime remained constant during the study period (continuous grazing). All three temporal variables were best predicted using models that included local abiotic variables, demonstrating strong spatial variation in temporal dynamics. Temporal fluctuation and compositional change depended on functional composition in the pre-treatment period (Figs 5 and 6), indicating that functional composition plays a role in how communities respond to external drivers. Directional change and temporal fluctuations were best predicted using a combination of external drivers (disturbance) and local variables (Figs 4 and 5), while compositional change was influenced only by local abiotic variables and functional composition (Table 1, Fig 6). Directional change was related to local abiotic factors but not functional composition, and was most pronounced on south-facing slopes (Table 1, Fig 4). Compositional change was unrelated to disturbance, and was highest on plots with high clay, C:N ratio, and forb composition as well as low topographic slope (Fig 6). Temporal fluctuation was greatest at plots with low perennial cover, and where disturbance was modified during the study period, either with burning or grazing removal (Figs 4 and 5).


Hotspots of Community Change: Temporal Dynamics Are Spatially Variable in Understory Plant Composition of a California Oak Woodland.

Spotswood EN, Bartolome JW, Allen-Diaz B - PLoS ONE (2015)

Temporal fluctuation and functional composition.Relationships between temporal fluctuation and functional composition (perennial cover %)during the pre-treatment period between 1998 and 2001 when a fence was installed to exclude grazing from one experimental watershed. Temporal fluctuation is quantified as the root mean square of the residuals from the linear regression line relating time lag to Bray-Curtis dissimilarity in species composition, calculated at the plot level.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4519272&req=5

pone.0133501.g005: Temporal fluctuation and functional composition.Relationships between temporal fluctuation and functional composition (perennial cover %)during the pre-treatment period between 1998 and 2001 when a fence was installed to exclude grazing from one experimental watershed. Temporal fluctuation is quantified as the root mean square of the residuals from the linear regression line relating time lag to Bray-Curtis dissimilarity in species composition, calculated at the plot level.
Mentions: Both directional change and temporal fluctuations were related to disturbance type (Fig 4). Directional changes were most pronounced on plots where grazing was removed, and fluctuations were least pronounced on plots where disturbance regime remained constant during the study period (continuous grazing). All three temporal variables were best predicted using models that included local abiotic variables, demonstrating strong spatial variation in temporal dynamics. Temporal fluctuation and compositional change depended on functional composition in the pre-treatment period (Figs 5 and 6), indicating that functional composition plays a role in how communities respond to external drivers. Directional change and temporal fluctuations were best predicted using a combination of external drivers (disturbance) and local variables (Figs 4 and 5), while compositional change was influenced only by local abiotic variables and functional composition (Table 1, Fig 6). Directional change was related to local abiotic factors but not functional composition, and was most pronounced on south-facing slopes (Table 1, Fig 4). Compositional change was unrelated to disturbance, and was highest on plots with high clay, C:N ratio, and forb composition as well as low topographic slope (Fig 6). Temporal fluctuation was greatest at plots with low perennial cover, and where disturbance was modified during the study period, either with burning or grazing removal (Figs 4 and 5).

Bottom Line: Temporal dynamics are often assumed to be relatively static at the landscape scale, provided disturbance and climate are continuous.This study shows that local and landscape scale factors jointly influence temporal dynamics creating hotspots that are particularly responsive to climate and disturbance.Thus, adequate predictions of response to disturbance or to changing climate will only be achieved by considering how factors at multiple spatial scales influence community resilience and recovery.

View Article: PubMed Central - PubMed

Affiliation: Department of Environmental Science, Policy and Management, University of California, Berkeley, California, United States of America.

ABSTRACT
Community response to external drivers such climate and disturbance can lead to fluctuations in community composition, or to directional change. Temporal dynamics can be influenced by a combination of drivers operating at multiple spatial scales, including external landscape scale drivers, local abiotic conditions, and local species pools. We hypothesized that spatial variation in these factors can create heterogeneity in temporal dynamics within landscapes. We used understory plant species composition from an 11 year dataset from a California oak woodland to compare plots where disturbance was experimentally manipulated with the removal of livestock grazing and a prescribed burn. We quantified three properties of temporal variation: compositional change (reflecting the appearance and disappearance of species), temporal fluctuation, and directional change. Directional change was related most strongly to disturbance type, and was highest at plots where grazing was removed during the study. Temporal fluctuations, compositional change, and directional change were all related to intrinsic abiotic factors, suggesting that some locations are more responsive to external drivers than others. Temporal fluctuations and compositional change were linked to local functional composition, indicating that environmental filters can create subsets of the local species pool that do not respond in the same way to external drivers. Temporal dynamics are often assumed to be relatively static at the landscape scale, provided disturbance and climate are continuous. This study shows that local and landscape scale factors jointly influence temporal dynamics creating hotspots that are particularly responsive to climate and disturbance. Thus, adequate predictions of response to disturbance or to changing climate will only be achieved by considering how factors at multiple spatial scales influence community resilience and recovery.

No MeSH data available.


Related in: MedlinePlus