Predicting fire-based perennial bunchgrass mortality in big sagebrush plant communities

2015 ◽  
Vol 24 (4) ◽  
pp. 527 ◽  
Author(s):  
Chad S. Boyd ◽  
Kirk W. Davies ◽  
April Hulet
Keyword(s):  
Plant Community ◽  
Plant Communities ◽  
Perennial Grass ◽  
Basal Area ◽  
Grass Species ◽  
Individual Plant ◽  
Ecological Sites ◽  
Big Sagebrush ◽  
Ecological Site ◽  
Fire Characteristics

Maintenance and post-fire rehabilitation of perennial bunchgrasses is important for reducing the spread of exotic annual grass species in big sagebrush plant communities. Post-fire rehabilitation decisions are hampered by a lack of tools for determining extent of fire-induced perennial grass mortality. Our objective was to correlate post-fire characteristics with perennial bunchgrass mortality at the plant and plant community scales. We recorded basal area, percent char, depth of burn and soil colour for 174 bunchgrasses across four ecological sites after a 65 000 ha wildfire in south-east Oregon and assessed plant mortality. Mortality was correlated with post-fire soil colour and ecological site; soil colours (black and grey) associated with pre-fire shrub presence had up to five-fold higher mortality than brown soils typical of interspace locations. Models incorporating depth of burn and soil colour correctly predicted mortality for 90% of individual plants; cover of brown soil explained 88% of the variation in bunchgrass mortality at the plant community scale. Our results indicate that soil colour and depth of burn are accurate predictors of bunchgrass mortality at individual plant and plant community scales and could be used to spatially allocate post-fire bunchgrass rehabilitation resources.

scholarly journals Plant communities as drivers of soil respiration: pathways, mechanisms, and significance for global change

2011 ◽  
Vol 8 (8) ◽  
pp. 2047-2061 ◽  
Author(s):  
D. B. Metcalfe ◽  
R. A. Fisher ◽  
D. A. Wardle
Keyword(s):  
Plant Community ◽  
Plant Communities ◽  
Plant Traits ◽  
Terrestrial Ecosystems ◽  
Climate Impacts ◽  
Individual Species ◽  
Global Changes ◽  
Individual Plant ◽  
Vegetation Types ◽  
Species Invasions

Abstract. Understanding the impacts of plant community characteristics on soil carbon dioxide efflux (R) is a key prerequisite for accurate prediction of the future carbon (C) balance of terrestrial ecosystems under climate change. However, developing a mechanistic understanding of the determinants of R is complicated by the presence of multiple different sources of respiratory C within soil – such as soil microbes, plant roots and their mycorrhizal symbionts – each with their distinct dynamics and drivers. In this review, we synthesize relevant information from a wide spectrum of sources to evaluate the current state of knowledge about plant community effects on R, examine how this information is incorporated into global climate models, and highlight priorities for future research. Despite often large variation amongst studies and methods, several general trends emerge. Mechanisms whereby plants affect R may be grouped into effects on belowground C allocation, aboveground litter properties and microclimate. Within vegetation types, the amount of C diverted belowground, and hence R, may be controlled mainly by the rate of photosynthetic C uptake, while amongst vegetation types this should be more dependent upon the specific C allocation strategies of the plant life form. We make the case that plant community composition, rather than diversity, is usually the dominant control on R in natural systems. Individual species impacts on R may be largest where the species accounts for most of the biomass in the ecosystem, has very distinct traits to the rest of the community and/or modulates the occurrence of major natural disturbances. We show that climate vegetation models incorporate a number of pathways whereby plants can affect R, but that simplifications regarding allocation schemes and drivers of litter decomposition may limit model accuracy. We also suggest that under a warmer future climate, many plant communities may shift towards dominance by fast growing plants which produce large quantities of nutrient rich litter. Where this community shift occurs, it could drive an increase in R beyond that expected from direct climate impacts on soil microbial activity alone. We identify key gaps in knowledge and recommend them as priorities for future work. These include the patterns of photosynthate partitioning amongst belowground components, ecosystem level effects of individual plant traits, and the importance of trophic interactions and species invasions or extinctions for ecosystem processes. A final, overarching challenge is how to link these observations and drivers across spatio-temporal scales to predict regional or global changes in R over long time periods. A more unified approach to understanding R, which integrates information about plant traits and community dynamics, will be essential for better understanding, simulating and predicting patterns of R across terrestrial ecosystems and its role within the earth-climate system.

The response to moisture and defoliation stresses, and traits for resilience of perennial grasses on the Northern Tablelands of New South Wales, Australia

2003 ◽  
Vol 54 (9) ◽  
pp. 903 ◽  
Author(s):  
S. P. Boschma ◽  
M. J. Hill ◽  
J. M. Scott ◽  
G. G. Rapp
Keyword(s):  
Festuca Arundinacea ◽  
Plant Biomass ◽  
Nitrogen Concentration ◽  
Perennial Grass ◽  
Basal Area ◽  
Perennial Grasses ◽  
Rooting Depth ◽  
Grass Species ◽  
Severe Drought ◽  
Moderate Drought

A field experiment was conducted to study the effects of defoliation and moisture stresses on perennial pasture grasses and to identify traits associated with their resilience. The experiment, conducted near Armidale on the Northern Tablelands of NSW, studied 4 introduced perennial grass species (Phalaris aquatica, Festuca arundinacea, Dactylis glomerata, and Lolium perenne) and 2 native grass species (Microlaena stipoides and Austrodanthonia richardsonii) subjected to 3 moisture regimes (non-stress moisture, moderate drought, and severe drought) and 2 defoliation intensities (severe and moderate). Basal area, herbage mass, phenological growth stage, nitrogen concentration, root mass, and rooting depth were compared over 2 independent 6-month periods: spring–summer (1 September 1994–28 February 1995) and summer–autumn (1 December 1994–31 May 1995). Multiple regression was used to determine which traits were important for determining plant resilience.The differences between species and their respective responses were evident in the traits measured. In general, basal area tended to increase over summer and show little change during autumn. Severe defoliation stimulated plant growth, resulting in higher harvested herbage mass than from those moderately defoliated. Reproductive development was suppressed by severe drought and reduced by moderate drought. Severe defoliation suppressed flowering of Dactylis and Lolium at both drought intensities, compared with moderate defoliation. Phalaris, Festuca, and Austrodanthonia were the deepest rooting species during spring–summer, and Dactylis the shallowest. All species had similar rooting depths during summer–autumn, with those under severe and moderate drought having the deepest and shallowest rooting, respectively.Carbohydrate reserves and basal area were important traits for determining plant resilience during spring–summer. During summer–autumn, maintaining basal area and plant biomass through moderate grazing was important for resilience.

Effect of Aminopyralid on Canada Thistle (Cirsium arvense) and the Native Plant Community in a Restored Tallgrass Prairie

2010 ◽  
Vol 3 (2) ◽  
pp. 155-168 ◽  
Author(s):  
Travis L. Almquist ◽  
Rodney G. Lym
Keyword(s):  
Plant Community ◽  
Plant Communities ◽  
Native Species ◽  
Cirsium Arvense ◽  
Grass Species ◽  
Stem Density ◽  
Native Plant ◽  
Canada Thistle ◽  
Native Plant Community ◽  
Restored Prairie

AbstractAminopyralid efficacy on Canada thistle (Cirsium arvense) and potential to injure native species was evaluated in a restored prairie at the Glacial Ridge Preserve managed by The Nature Conservancy in Polk County, MN. Canada thistle stem density was reduced from 17 to 0.1 stems m−2 10 mo after treatment (MAT) with aminopyralid applied in the fall at 120 g ha−1. Aminopyralid also altered the composition of both Canada thistle–infested and native plant communities. Aminopyralid controlled Canada thistle and removed or reduced several undesirable forb species from the restored prairie communities, such as absinth wormwood (Artemisia absinthium) and perennial sowthistle (Sonchus arvensis). A number of high seral forbs were also reduced or removed by aminopyralid, including maximilian sunflower (Helianthus maximiliani) and purple prairie clover (Dalea purpurea). Foliar cover of high seral forbs in the native plant community was reduced from 12.2 to 7% 22 MAT. The cover of high seral grass species, such as big bluestem (Andropogon gerardii) and Indiangrass (Sorghastrum nutans) increased after aminopyralid application in both the Canada thistle–infested and native plant communities and averaged 41.4% cover compared with only 19.4% before removal of Canada thistle. Species richness, evenness, and diversity were reduced after aminopyralid application in both Canada thistle–infested and native plant communities. However, the benefits of Canada thistle control, removal of undesirable species, and the increase in native grass cover should lead to an overall improvement in the long-term stability and composition of the restored prairie plant community, which likely outweigh the short-term effects of a Canada thistle control program.

scholarly journals Shrub, Scrub, and Grass: The Importance of Shrubland and Grassland Plant Communities to the Diet of the Late Prehistoric (A.D. 900-1535) Hunter-Gatherers of the Eastern Trans-Pecos Region of Texas

2014 ◽  
Author(s):  
Casey Riggs
Keyword(s):  
Plant Communities ◽  
Analytical Techniques ◽  
Landscape Scale ◽  
Late Prehistoric ◽  
Hunter Gatherers ◽  
Ecological Sites ◽  
Ecological Site ◽  
The Past ◽  
Botanical Diversity ◽  
Degree Of Similarity

The Eastern Trans-Pecos archeological region of Texas is an area rich in botanical diversity, a resource heavily utilized by both prehistoric and historic hunter-gatherers. A comparison of four paleoethnobotanical investigations of archeological sites dating to the Late Prehistoric Era (A.D. 900-1535) with ethnobotanical information of the Mescalero Apache reveal that the botanical component of prehistoric and historic diets have been similar for the past 1,000 years. Differences in the degree of similarity can be contributed to differential preservation and analytical techniques. Further, ecological sites from the Ecological Site Information System are demonstrated as a novel and useful tool for landscape-scale archeological analysis.

scholarly journals Relationships Between Soil Microbial Communities and Plant Communities on Different Slope Aspects in a Subalpine Coniferous Forest

2021 ◽  
Author(s):  
Luoshu He ◽  
Suhui Ma ◽  
Jiangling Zhu ◽  
Xinyu Xiong ◽  
Yangang Li ◽  
...  
Keyword(s):  
Species Richness ◽  
Plant Community ◽  
Plant Communities ◽  
Soil Microbial Communities ◽  
Basal Area ◽  
Coniferous Forests ◽  
Slope Aspect ◽  
Soil Microbial ◽  
Plant Soil ◽  
The Relationship

Abstract Purpose The local microclimate of different slope aspects in the same area can not only impact soil environment and plant community but also affect soil microbial community. However, the relationship between aboveground plant communities and belowground soil microbial communities on various slope aspects has not been well understood.Methods We investigated the above- and belowground relationship on different slope aspects and explored how soil properties influence this relationship. Plant community attributes were evaluated by plant species richness and plant total basal area. Soil microbial community was assessed based on both 16S rRNA and ITS rRNA, using High-throughput Illumina sequencing. Results There was no significant correlation between plant richness and soil bacterial community composition on the north slope, but there was a positive correlation on the south slope and a significantly negative correlation on the flat site. There was a significantly negative correlation between soil fungal community composition and plant total basal area, which did not change with the slope aspect. In addition, there was no significant correlation between plant community species richness and soil microbial species richness.Conclusions In subalpine coniferous forests, the relationship between plant-soil bacteria varies with slope aspect, but the plant-soil fungi relationship is relatively consistent across different slope aspects. These results can improve our understanding of the relationship between plant and soil microorganisms in forest ecosystems under microtopographic changes and have important implications for the conservation of biodiversity and forest management in subalpine coniferous forests.

Divergent responses to long-term grazing exclusion among three plant communities in a flood pulsing wetland in eastern Australia.

2014 ◽  
Vol 20 (3) ◽  
pp. 237 ◽  
Author(s):  
Peter J Berney ◽  
G. Glenn Wilson ◽  
Darren S. Ryder ◽  
R.D.B Whalley ◽  
John Duggin ◽  
...  
Keyword(s):  
Species Richness ◽  
Community Composition ◽  
Plant Community ◽  
Plant Communities ◽  
Dominant Species ◽  
Grass Species ◽  
Grazing Exclusion ◽  
Eastern Australia ◽  
Domestic Livestock ◽  
Over Time

We examined the effects of grazing exclusion over a period of 14 years on the species richness and community composition of three plant communities with different dominant species and water regimes in the Gwydir Wetlands in eastern Australia. Responses to grazing exclusion varied among the three plant communities, and were most likely to be evident during dry periods rather than during periods of inundation. In frequently flooded plant communities, there was an increase in phytomass following exclusion of domestic livestock, but changes in plant community composition and species richness due to livestock exclusion varied depending on the morphological attributes of the dominant plant species. In a plant community where tall sedge species were dominant, livestock exclusion further increased their dominance and overall species richness declined. In contrast, where a prostrate grass species such as Paspalum distichum was dominant, species richness increased following livestock exclusion, due to an increase in the abundance of taller dicotyledon species. However, livestock exclusion in a community where flooding was less frequent and native grass species have been largely replaced with the introduced species Phyla canescens, resulted in no significant changes to phytomass, species richness or community composition among the grazing exclusion treatments over time. Our results indicate responses to exclusion of domestic livestock are dependent upon the dominant species within the plant community and will likely vary over time with the extent of wetland inundation. Grazing exclusion alone, without increased flooding, is unlikely to restore floristically degraded floodplain plant communities.

scholarly journals Primary sand-dune plant community and soil properties during the west-coast India monsoon

2016 ◽  
Vol 2 (1) ◽  
pp. 60-71 ◽  
Author(s):  
A. Willis ◽  
P.J.C Harris ◽  
B.F. Rodrigues ◽  
T.H. Sparks
Keyword(s):  
Plant Community ◽  
West Coast ◽  
Perennial Grass ◽  
Grass Species ◽  
Nutrient Concentrations ◽  
Tropical Region ◽  
Soil Water Retention ◽  
Dune System ◽  
Dune Plant ◽  
Quadrat Survey

Abstract A seven-station interrupted belt transect was established that followed a previously observed plant zonation pattern across an aggrading primary coastal dune system in the dry tropical region of west-coast India. The dominant weather pattern is monsoon from June to November, followed by hot and dry winter months when rainfall is scarce. Physical and chemical soil characteristics in each of the stations were analysed on five separate occasions, the first before the onset of monsoon, three during and the last post-monsoon. The plant community pattern was confirmed by quadrat survey. A pH gradient decreased with distance from the shoreline. Nutrient concentrations were deficient, increasing only in small amounts until the furthest station inland. At that location, there was a distinct and abrupt pedological transition zone from psammite to humic soils. There was a significant increase over previous stations in mean organic matter, ammonium nitrate and soil-water retention, although the increase in real terms was small. ANOVA showed significant variation in electrical conductivity, phosphorus, calcium, magnesium and sodium concentrations over time. There was no relationship between soil chemistry characteristics and plant community structure over the transect. Ipomoea pes-caprae and Spinifex littoreus were restricted to the foredunes, the leguminous forb Alysicarpus vaginalis and Perotis indica to the two stations furthest from the strand. Ischaemum indicum, a C4 perennial grass species adopting an ephemeral strategy was, in contrast, ubiquitous to all stations.

The comparative ecologo-phytocoenotical positions of the two feather-grass species (Stipa pennata L. and S. tirsa Stev.) in the plant communities of Yamskaya Steppe (Belgorod region)

2011 ◽  
pp. 29-54
Author(s):  
B. K. Gannibal
Keyword(s):  
Plant Community ◽  
Plant Communities ◽  
Grass Species ◽  
Steppe Communities ◽  
Protected Territory ◽  
Feather Grass

There is a general phytocoenotic question — why the species similar taxonomically and ecologically can co-exist within a plant community? The paper deals with two of such species — Stipa pennata L. and S. tirsa Stev., that previously were considered by plant taxonomists as one species. They are reputed to be the most mesophytic feather-grasses, although there are a lot of contradictory opinions about their physiology and ecology. In 1920s and 30s two well-known Russian geobotanists B. Keller and V. Aljekhin conflicted on the problem. In our case both species co-exist in the steppe communities of the protected territory (zapovednik “Belogorie”). The phytocoenotical role of feather-grassesvaries in the different ecotopes. The phytocoenotical roles S. pennata and S. tirsa are very similar in the plant communities growing on the cold slopes. As for the warm sites, the participation of S. pennata in the communities is the same, whereas a presence of S. tirsa is considerably decreased. Each feather-grass de­monstrates a high correlation with specific grass species of communities. The obtained results show the clear phytocoenotic distinctions between two species.

scholarly journals Cost-benefit Quantification of Leaf Carbon Economics to Disentangle Responses of Plant Assemblages to Deer Herbivory

2021 ◽  
Author(s):  
Yuki Wakatsuki ◽  
Keita Nishizawa ◽  
Akira S Mori
Keyword(s):  
Community Composition ◽  
Plant Community ◽  
Plant Communities ◽  
Dominance Rank ◽  
Cost Benefit ◽  
Forest Understory ◽  
Individual Plant ◽  
Plant Community Composition ◽  
Carbon Cost ◽  
Deer Herbivory

Abstract Although the plant carbon cost-benefit balance is known to be related to individual plant growth, reproduction, and population expansion, the association with plant community differences is not well understood. In this study, we examined how the leaf carbon cost-benefit metrics were associated with the assembly process of forest understory plant communities in areas highly affected by deer browsing. We calculated these metrics from plant physiologically parameters for 14 forest floor plant species growing in deer presence/absence site to detect the relationship between species dominance and leaf carbon cost-benefit metrics. As a result, the patterns of interspecific variation in benefit along the plant dominance rank differed in deer presence/absence sites, contributing to the marked differences in species composition and diversity observed at the two sites. In the absence of deer, where competition was the dominant determinant of plant community composition, carbon benefits among species were positively related to the plant dominance rank, indicating that species able to acquire more carbon were at an advantage. On the other hand, under deer herbivory, differences in carbon benefit between species were not strongly apparent and were not related to the plant dominance rank, indicating few differences in reproductive and expansion ability (plant fitness) between species. This process contributes to the high species diversity of plant communities observed in the presence of deer. Our results emphasize the possibility of connecting different fields of studies, physiological ecology, community ecology, and the plant carbon cost-benefit balance of single leaves to explain plant community composition differences.

Temporal dynamics of mycorrhizal fungal communities and co-associations with grassland plant communities following experimental manipulation of rainfall

2019 ◽  
Author(s):  
Coline Deveautour ◽  
Sally Power ◽  
Kirk Barnett ◽  
Raul Ochoa-Hueso ◽  
Suzanne Donn ◽  
...  
Keyword(s):  
Community Composition ◽  
Plant Community ◽  
Plant Communities ◽  
Fungal Community ◽  
Mycorrhizal Fungi ◽  
Temporal Dynamics ◽  
Arbuscular Mycorrhizal ◽  
Fungal Communities ◽  
Plant Responses ◽  
Rainfall Regimes

Climate models project overall a reduction in rainfall amounts and shifts in the timing of rainfall events in mid-latitudes and sub-tropical dry regions, which threatens the productivity and diversity of grasslands. Arbuscular mycorrhizal fungi may help plants to cope with expected changes but may also be impacted by changing rainfall, either via the direct effects of low soil moisture on survival and function or indirectly via changes in the plant community. In an Australian mesic grassland (former pasture) system, we characterised plant and arbuscular mycorrhizal (AM) fungal communities every six months for nearly four years to two altered rainfall regimes: i) ambient, ii) rainfall reduced by 50% relative to ambient over the entire year and iii) total summer rainfall exclusion. Using Illumina sequencing, we assessed the response of AM fungal communities sampled from contrasting rainfall treatments and evaluated whether variation in AM fungal communities was associated with variation in plant community richness and composition. We found that rainfall reduction influenced the fungal communities, with the nature of the response depending on the type of manipulation, but that consistent results were only observed after more than two years of rainfall manipulation. We observed significant co-associations between plant and AM fungal communities on multiple dates. Predictive co-correspondence analyses indicated more support for the hypothesis that fungal community composition influenced plant community composition than vice versa. However, we found no evidence that altered rainfall regimes were leading to distinct co-associations between plants and AM fungi. Overall, our results provide evidence that grassland plant communities are intricately tied to variation in AM fungal communities. However, in this system, plant responses to climate change may not be directly related to impacts of altered rainfall regimes on AM fungal communities. Our study shows that AM fungal communities respond to changes in rainfall but that this effect was not immediate. The AM fungal community may influence the composition of the plant community. However, our results suggest that plant responses to altered rainfall regimes at our site may not be resulting via changes in the AM fungal communities.

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