2009
Cruz-Martínez, Brodie EL Suttle KB
Despite strong seasonal responses, soil microbial consortia are more resilient to long-term changes in rainfall than overlying grassland. Journal Article
In: The ISME Journal, vol. 3, pp. 738–744, 2009.
Abstract | Links | BibTeX | Tags: climate change, cosmogenic isotope, grasslands, microbial communities, rainfall, soil
@article{doi:10.1038/ismej.2009.16,
title = {Despite strong seasonal responses, soil microbial consortia are more resilient to long-term changes in rainfall than overlying grassland.},
author = {Brodie EL Suttle KB Cruz-Martínez},
url = {https://angelo.berkeley.edu/wp-content/uploads/sites/59/Cruz_2009_ISME.pdf},
doi = {doi:10.1038/ismej.2009.16},
year = {2009},
date = {2009-03-12},
journal = {The ISME Journal},
volume = {3},
pages = {738–744},
abstract = {Climate change impacts on soil microbial communities could alter the structure of terrestrial ecosystems and biogeochemical cycles of the Earth. We used 16S rRNA gene microarrays to evaluate changes in the composition of grassland soil microbial communities under rainfall amendments simulating alternative climate change scenarios, and to compare these to responses of overlying plants and invertebrates. Following 5 years of rainfall manipulation, soil bacteria and archaea in plots where natural rain was supplemented differed little from ambient controls, despite profound treatment-related changes in the overlying grassland. During the sixth and seventh year, seasonal differences in bacterial and archaeal assemblages emerged among treatments, but only when watering exacerbated or alleviated periods of particularly aberrant conditions in the ambient climate. In contrast to effects on plants and invertebrates, effects on bacteria and archaea did not compound across seasons or years, indicating that soil microbial communities may be more robust than associated aboveground macroorganisms to certain alterations in climate.},
keywords = {climate change, cosmogenic isotope, grasslands, microbial communities, rainfall, soil},
pubstate = {published},
tppubtype = {article}
}
Climate change impacts on soil microbial communities could alter the structure of terrestrial ecosystems and biogeochemical cycles of the Earth. We used 16S rRNA gene microarrays to evaluate changes in the composition of grassland soil microbial communities under rainfall amendments simulating alternative climate change scenarios, and to compare these to responses of overlying plants and invertebrates. Following 5 years of rainfall manipulation, soil bacteria and archaea in plots where natural rain was supplemented differed little from ambient controls, despite profound treatment-related changes in the overlying grassland. During the sixth and seventh year, seasonal differences in bacterial and archaeal assemblages emerged among treatments, but only when watering exacerbated or alleviated periods of particularly aberrant conditions in the ambient climate. In contrast to effects on plants and invertebrates, effects on bacteria and archaea did not compound across seasons or years, indicating that soil microbial communities may be more robust than associated aboveground macroorganisms to certain alterations in climate.
2004
Kotanen, Peter M.
Revegetation following Soil Disturbance and Invasion in a Californian Meadow: a 10-year History of Recovery Journal Article
In: Biological Invasions, vol. 6, no. 2, pp. 245–254, 2004, ISSN: 1573-1464.
Abstract | Links | BibTeX | Tags: aliens, disturbance, exotics, feral pigs, grasslands, invasions, restoration, succession
@article{Kotanen2004,
title = {Revegetation following Soil Disturbance and Invasion in a Californian Meadow: a 10-year History of Recovery},
author = {Peter M. Kotanen},
url = {https://angelo.berkeley.edu/wp-content/uploads/sites/59/Revegetation-following-Soil-Disturbance-and-Invasion-in-a-Californian-Meadow-a-10-year-History-of-Recovery-Biological-Invasions_Kotanen1.pdf},
doi = {10.1023/B:BINV.0000022145.03215.4f},
issn = {1573-1464},
year = {2004},
date = {2004-00-00},
journal = {Biological Invasions},
volume = {6},
number = {2},
pages = {245–254},
abstract = {Disturbance is necessary for the regeneration of many native plant species, but can also facilitate biological invasions. As a result, disturbance can play complex roles in vulnerable habitats such as remnant Californian perennial grasslands. To investigate these conflicts, plots in a northern Californian coastal grassland were experimentally disturbed in the winter of 1990-1991; these plots differed in the area and intensity (depth) of the soil disturbance applied. When these plots were revisited after 10 growing seasons, patterns of revegetation differed significantly from those observed early in recolonization (0-3 years). At the earlier samplings, exotic annual grasses rapidly increased in most disturbance types. After 10 years, these exotic annuals had retreated from the depth experiment, which had recovered to a vegetation dominated by native perennials in all but the most severely disturbed plots. In contrast, although differences between control and disturbed plots also disappeared in the area experiment, the average abundance of aliens did not decline substantially relative to 1993 levels, especially in larger disturbances. Nonetheless, populations of aliens remained small compared to the peak populations in the depth experiment, probably reflecting wetter soils at the site used for the area experiment. These results differ from those of other recent studies of soil disturbance in coastal Californian ecosystems, which indicate disturbance may result in the permanent replacement of native perennial vegetation by dense populations of exotic annual grasses. This difference may reflect the high resilience of northern coastal grasslands as well as the scale of disturbances considered by different studies.},
keywords = {aliens, disturbance, exotics, feral pigs, grasslands, invasions, restoration, succession},
pubstate = {published},
tppubtype = {article}
}
Disturbance is necessary for the regeneration of many native plant species, but can also facilitate biological invasions. As a result, disturbance can play complex roles in vulnerable habitats such as remnant Californian perennial grasslands. To investigate these conflicts, plots in a northern Californian coastal grassland were experimentally disturbed in the winter of 1990-1991; these plots differed in the area and intensity (depth) of the soil disturbance applied. When these plots were revisited after 10 growing seasons, patterns of revegetation differed significantly from those observed early in recolonization (0-3 years). At the earlier samplings, exotic annual grasses rapidly increased in most disturbance types. After 10 years, these exotic annuals had retreated from the depth experiment, which had recovered to a vegetation dominated by native perennials in all but the most severely disturbed plots. In contrast, although differences between control and disturbed plots also disappeared in the area experiment, the average abundance of aliens did not decline substantially relative to 1993 levels, especially in larger disturbances. Nonetheless, populations of aliens remained small compared to the peak populations in the depth experiment, probably reflecting wetter soils at the site used for the area experiment. These results differ from those of other recent studies of soil disturbance in coastal Californian ecosystems, which indicate disturbance may result in the permanent replacement of native perennial vegetation by dense populations of exotic annual grasses. This difference may reflect the high resilience of northern coastal grasslands as well as the scale of disturbances considered by different studies.
2000
Levine, Jonathan M.
Species diversity and biological invasions: relating local process to community pattern Journal Article
In: Science, vol. 288, no. 5467, pp. 852-854, 2000, ISSN: 0036-8075.
Abstract | Links | BibTeX | Tags: biodiversity, ecosystem, grasslands, invasibility, resistance, stability
@article{Levine2000b,
title = {Species diversity and biological invasions: relating local process to community pattern},
author = {Jonathan M. Levine},
url = {https://angelo.berkeley.edu/wp-content/uploads/sites/59/Science-2000-Levine-852-4.pdf},
issn = {0036-8075},
year = {2000},
date = {2000-05-05},
journal = {Science},
volume = {288},
number = {5467},
pages = {852-854},
abstract = {In a California riparian system, the most diverse natural assemblages are the most invaded by exotic plants. A direct in situ manipulation of local diversity and a seed addition experiment showed that these patterns emerge despite the intrinsic negative effects of diversity on invasions. The results suggest that species loss at small scales may reduce invasion resistance. At community-wide scales, the overwhelming effects of ecological factors spatially covarying with diversity, such as propagule supply, make the most diverse communities most likely to be invaded.},
keywords = {biodiversity, ecosystem, grasslands, invasibility, resistance, stability},
pubstate = {published},
tppubtype = {article}
}
In a California riparian system, the most diverse natural assemblages are the most invaded by exotic plants. A direct in situ manipulation of local diversity and a seed addition experiment showed that these patterns emerge despite the intrinsic negative effects of diversity on invasions. The results suggest that species loss at small scales may reduce invasion resistance. At community-wide scales, the overwhelming effects of ecological factors spatially covarying with diversity, such as propagule supply, make the most diverse communities most likely to be invaded.
1997
Kotanen, Peter M.
Effects of gap area and shape on recolonization by grasslands plants with differing reproductive strategies Journal Article
In: Canadian Journal of Botany, vol. 75, no. 2, pp. 352 – 361, 1997, ISSN: 0008-4026.
Abstract | Links | BibTeX | Tags: disturbance, gap shape, gap size, grasslands, revegetation, succession
@article{Kotanen1997b,
title = {Effects of gap area and shape on recolonization by grasslands plants with differing reproductive strategies},
author = {Peter M. Kotanen},
url = {https://angelo.berkeley.edu/wp-content/uploads/sites/59/Kotanen_CanadianJournalofBotany1997.pdf},
issn = {0008-4026},
year = {1997},
date = {1997-02-00},
journal = {Canadian Journal of Botany},
volume = {75},
number = {2},
pages = {352 - 361},
abstract = {Species with poor dispersal ability initially should be slower to colonize larger or rounder gaps than smaller or less circular gaps. Conversely, dispersive and seed-banking species should be less sensitive than poor dispersers to gap size and shape, and less confined near the edges of a gap. I tested these ideas with a 3-year experiment in which I monitored the revegetation of gaps in grassland vegetation. Initially, species reproducing largely by clonal growth (bulbs and perennial graminoids) were the most sensitive to gap size and (to a lesser extent) shape, reaching their greatest abundances in small and (or) rectangular openings. Species relying on seed dispersal (annual grasses) also tended to do best in smaller plots, but were less concentrated near the edges of the plots. Species relying on seed dormancy (dicots and Juncus bufonius) were least sensitive to plot size, shape, and distance from an edge. In subsequent years, these patterns often were obscured or reversed, reflecting continuing seed immigration and environmental and competitive conditions within gaps. These results indicate that species respond to gap size and shape in ways consistent with their reproductive biologies, and suggest that the importance of the dimensions of gaps may vary among plant communities.},
keywords = {disturbance, gap shape, gap size, grasslands, revegetation, succession},
pubstate = {published},
tppubtype = {article}
}
Species with poor dispersal ability initially should be slower to colonize larger or rounder gaps than smaller or less circular gaps. Conversely, dispersive and seed-banking species should be less sensitive than poor dispersers to gap size and shape, and less confined near the edges of a gap. I tested these ideas with a 3-year experiment in which I monitored the revegetation of gaps in grassland vegetation. Initially, species reproducing largely by clonal growth (bulbs and perennial graminoids) were the most sensitive to gap size and (to a lesser extent) shape, reaching their greatest abundances in small and (or) rectangular openings. Species relying on seed dispersal (annual grasses) also tended to do best in smaller plots, but were less concentrated near the edges of the plots. Species relying on seed dormancy (dicots and Juncus bufonius) were least sensitive to plot size, shape, and distance from an edge. In subsequent years, these patterns often were obscured or reversed, reflecting continuing seed immigration and environmental and competitive conditions within gaps. These results indicate that species respond to gap size and shape in ways consistent with their reproductive biologies, and suggest that the importance of the dimensions of gaps may vary among plant communities.