1
|
Sonnier G, Boughton EH, Whittington R. Long-term response of wetland plant communities to management intensity, grazing abandonment, and prescribed fire. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2023; 33:e2732. [PMID: 36054269 PMCID: PMC10078234 DOI: 10.1002/eap.2732] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2021] [Revised: 05/09/2022] [Accepted: 05/31/2022] [Indexed: 05/12/2023]
Abstract
Isolated, seasonal wetlands within agricultural landscapes are important ecosystems. However, they are currently experiencing direct and indirect effects of agricultural management surrounding them. Because wetlands provide important ecosystem services, it is crucial to determine how these factors affect ecological communities. Here, we studied the long-term effects of land-use intensification, cattle grazing, prescribed fires, and their interactions on wetland plant diversity, community dynamics, and functional diversity. To do this, we used vegetation and trait data from a 14-year-old experiment on 40 seasonal wetlands located within seminatural and intensively managed pastures in Florida. These wetlands were allocated different grazing and prescribed fire treatments (grazed vs. ungrazed, burned vs. unburned). Our results showed that wetlands within intensively managed pastures have lower native plant diversity, floristic quality, evenness, and higher nonnative species diversity and exhibited the most resource-acquisitive traits. Wetlands embedded in intensively managed pastures were also characterized by lower species turnover over time. We found that 14 years of cattle exclusion reduced species diversity in both pasture management intensities and had no effect on floristic quality. Fenced wetlands exhibited lower functional diversity and experienced a higher rate of community change, both due to an increase in tall, clonal, and palatable grasses. The effects of prescribed fires were often dependent on grazing treatment. For instance, prescribed fires increased functional diversity in fenced wetlands but not in grazed wetlands. Our study suggests that cattle exclusion and prescribed fires are not enough to restore wetlands in intensively managed pastures and further highlights the importance of not converting seminatural pastures to intensively managed pastures. Our study also suggests that grazing levels applied in seminatural pastures maintained high plant diversity and prevented tree and shrub encroachment and that in the absence of grazing, prescribed fire became crucial to maintaining higher species evenness.
Collapse
Affiliation(s)
| | | | - Ruth Whittington
- Archbold Biological StationVenusFloridaUSA
- Colorado Natural Heritage ProgramColorado State UniversityFort CollinsColoradoUSA
| |
Collapse
|
2
|
Aoyama L, Shoemaker LG, Gilbert B, Collinge SK, Faist AM, Shackelford N, Temperton VM, Barabás G, Larios L, Ladouceur E, Godoy O, Bowler C, Hallett LM. Application of modern coexistence theory to rare plant restoration provides early indication of restoration trajectories. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2022; 32:e2649. [PMID: 35560687 PMCID: PMC9787931 DOI: 10.1002/eap.2649] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 03/10/2022] [Accepted: 03/23/2022] [Indexed: 05/17/2023]
Abstract
Restoration ecology commonly seeks to re-establish species of interest in degraded habitats. Despite a rich understanding of how succession influences re-establishment, there are several outstanding questions that remain unaddressed: are short-term abundances sufficient to determine long-term re-establishment success, and what factors contribute to unpredictable restorations outcomes? In other words, when restoration fails, is it because the restored habitat is substandard, because of strong competition with invasive species, or alternatively due to changing environmental conditions that would equally impact established populations? Here, we re-purpose tools developed from modern coexistence theory to address these questions, and apply them to an effort to restore the endangered Contra Costa goldfields (Lasthenia conjugens) in constructed ("restored") California vernal pools. Using 16 years of data, we construct a population model of L. conjugens, a species of conservation concern due primarily to habitat loss and invasion of exotic grasses. We show that initial, short-term appearances of restoration success from population abundances is misleading, as year-to-year fluctuations cause long-term population growth rates to fall below zero. The failure of constructed pools is driven by lower maximum growth rates compared with reference ("natural") pools, coupled with a stronger negative sensitivity to annual fluctuations in abiotic conditions that yield decreased maximum growth rates. Nonetheless, our modeling shows that fluctuations in competition (mainly with exotic grasses) benefit L. conjugens through periods of competitive release, especially in constructed pools of intermediate pool depth. We therefore show how reductions in invasives and seed addition in pools of particular depths could change the outcome of restoration for L. conjugens. By applying a largely theoretical framework to the urgent goal of ecological restoration, our study provides a blueprint for predicting restoration success, and identifies future actions to reverse species loss.
Collapse
Affiliation(s)
- Lina Aoyama
- Biology DepartmentUniversity of OregonEugeneOregonUSA
- Environmental Studies ProgramUniversity of OregonEugeneOregonUSA
| | | | - Benjamin Gilbert
- Department of Ecology and Evolutionary BiologyUniversity of TorontoTorontoOntarioCanada
| | | | - Akasha M. Faist
- Department of Animal and Range SciencesNew Mexico State UniversityLas CrucesNew MexicoUSA
| | - Nancy Shackelford
- School of Environmental StudiesUniversity of VictoriaVictoriaBritish ColumbiaCanada
- Ecology and Evolutionary BiologyUniversity of Colorado BoulderBoulderColoradoUSA
| | | | - György Barabás
- Division of Theoretical Biology, Department of IFMLinköping UniversityLinköpingSweden
- MTA‐ELTE Theoretical Biology and Evolutionary Ecology Research GroupBudapestHungary
| | - Loralee Larios
- Department of Botany and Plant SciencesUniversity of California RiversideRiversideCaliforniaUSA
| | - Emma Ladouceur
- German Centre for Integrative Biodiversity Research (iDiv) Leipzig‐Halle‐JenaLeipzigGermany
- Department of Physiological DiversityHelmholtz Centre for Environmental Research –UFZLeipzigGermany
| | - Oscar Godoy
- Instituto Universitario de Investigación Marina (INMAR), Dpto de BiologíaPuerto RealSpain
| | - Catherine Bowler
- School of Biological Sciences University of QueenslandBrisbaneQueenslandAustralia
| | - Lauren M. Hallett
- Biology DepartmentUniversity of OregonEugeneOregonUSA
- Environmental Studies ProgramUniversity of OregonEugeneOregonUSA
| |
Collapse
|
3
|
Impact of Horse Grazing on Floristic Diversity in Mediterranean Small Standing-Water Ecosystems (SWEs). PLANTS 2022; 11:plants11121597. [PMID: 35736752 PMCID: PMC9227585 DOI: 10.3390/plants11121597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/21/2022] [Revised: 06/13/2022] [Accepted: 06/14/2022] [Indexed: 11/20/2022]
Abstract
Small standing-Water Ecosystems (SWEs), despite their pivotal ecological role due to their participation in hydrogeological processes and their richness in biodiversity, seem to be often overlooked by the scientific community. In this study, the vascular plant diversity in some representative SWEs, that host a peculiar assemblage of plant and animal species, was investigated in relation to the disturbance effects of a wild horse population. A total of 50 plots, equally distributed in small and large SWEs, were surveyed and a level of disturbance was attributed to each plot. We found greater species richness in small and undisturbed SWEs, which suggests the negative impact of horse grazing on the richness of plant species in this type of habitat. Significant differences in plant assemblage were found according to the disturbance level, whereas, contrary to what was observed for species richness, no differences were detected based on their size. The diversity indices, used to evaluate the richness and diversity in these areas, recorded the highest values for small and undisturbed areas. This result highlights that the disturbance of the horse grazing plays a pivotal role in affecting the diversity and richness of species in the SWEs. These findings suggest that SWE systems should be analyzed considering these areas as unique in order to allow the conservation of the plant richness and biodiversity of the SWE systems in conjunction with the protection of horses.
Collapse
|
4
|
Correa CMA, da Silva PG. Environmental drivers of taxonomic and functional diversity of dung beetles across a chronosequence of tropical grasslands with different cattle grazing removal ages. AUSTRAL ECOL 2022. [DOI: 10.1111/aec.13174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- César M. A. Correa
- Programa de Pós‐Graduação em Entomologia Universidade Federal de Lavras Lavras 37200‐000 Brazil
- Laboratório de Scarabaeoidologia Universidade Federal de Mato Grosso Cuiabá Brazil
| | - Pedro Giovâni da Silva
- Programa de Pós‐Graduação em Ecologia, Conservação e Manejo da Vida Silvestre Universidade Federal de Minas Gerais Belo Horizonte Brazil
| |
Collapse
|
5
|
Michaels JS, Tate KW, Eviner VT. Vernal pool wetlands respond to livestock grazing, exclusion and reintroduction. J Appl Ecol 2021. [DOI: 10.1111/1365-2664.14001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | - Kenneth W. Tate
- Department of Plant Sciences University of California Davis CA USA
| | | |
Collapse
|
6
|
Titcomb GC, Amooni G, Mantas JN, Young HS. The effects of herbivore aggregations at water sources on savanna plants differ across soil and climate gradients. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2021; 31:e02422. [PMID: 34288228 DOI: 10.1002/eap.2422] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 01/29/2021] [Accepted: 03/22/2021] [Indexed: 06/13/2023]
Abstract
Water sources in arid and semiarid ecosystems support humans, wildlife, and domestic animals, forming nodes of activity that sculpt surrounding plant communities and impact critical grazing and soil systems. However, global aridification and changing surface water supply threaten to disrupt these water resources, with strong implications for conservation and management of these ecosystems. To understand how effects of herbivore aggregation at water impact plant communities across contexts, we measured herbivore activity, plant height, cover (trees, grasses, forbs, and bare ground), diversity, and composition at 17 paired water sources and matrix sites across a range of abiotic factors in a semiarid savanna in Kenya. The effects of proximity to surface water and herbivore aggregation on plant communities varied substantially depending on soil and rainfall. In arid areas with nutrient-poor sandy soils, forb and tree cover were 50% lower at water sources compared to neighboring matrix sites, bare ground was 20% higher, species richness was 15% lower, and a single globally important grazing grass (Cynodon dactylon) dominated 60% of transects. However, in mesic areas with nutrient-rich finely textured soils, species richness was 25% higher, despite a 40% increase in bare ground, concurrent with the decline of a dominant tall grass (Themeda triandra) and increase in C. dactylon and other grass species near water sources. Recent rainfall was important for grasses; cover was higher relative to matrix sites only during wet periods, a potential indication of compensatory grazing. These findings suggest that effects of herbivore aggregation on vegetation diversity and composition will vary in magnitude, and in some cases direction, depending on other factors at the site. Where moisture and nutrient resources are high and promote the dominance of few plant species, herbivore aggregations may maintain diversity by promoting grazing lawns and increasing nondominant species cover. However, in arid conditions and sites with low nutrient availability, diversity can be substantially reduced by these aggregations. Our results highlight the importance of considering abiotic conditions when managing for effects of herbivore aggregations near water. This will be particularly important for future managers in light of growing global aridification and surface water changes.
Collapse
Affiliation(s)
- Georgia C Titcomb
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, Santa Barbara, California, 93106, USA
- Mpala Research Centre, Box 555, Nanyuki, 10400, Kenya
| | | | | | - Hillary S Young
- Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, Santa Barbara, California, 93106, USA
- Mpala Research Centre, Box 555, Nanyuki, 10400, Kenya
| |
Collapse
|
7
|
Rangeland Land-Sharing, Livestock Grazing’s Role in the Conservation of Imperiled Species. SUSTAINABILITY 2021. [DOI: 10.3390/su13084466] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Land sharing, conserving biodiversity on productive lands, is globally promoted. Much of the land highest in California’s biodiversity is used for livestock production, providing an opportunity to understand land sharing and species conservation. A review of United States Fish and Wildlife Service listing documents for 282 threatened and endangered species in California reveals a complex and varied relationship between grazing and conservation. According to these documents, 51% or 143 of the federally listed animal and plant species are found in habitats with grazing. While livestock grazing is a stated threat to 73% (104) of the species sharing habitat with livestock, 59% (85) of the species are said to be positively influenced, with considerable overlap between species both threatened and benefitting from grazing. Grazing is credited with benefiting flowering plants, mammals, insects, reptiles, amphibians, fish, crustaceans, and bird species by managing the state’s novel vegetation and providing and maintaining habitat structure and ecosystem functions. Benefits are noted for species across all of California’s terrestrial habitats, except alpine, and for some aquatic habitats, including riparian, wetlands, and temporary pools. Managed grazing can combat anthropomorphic threats, such as invasive species and nitrogen deposition, supporting conservation-reliant species as part of land sharing.
Collapse
|
8
|
Michaels J, Batzer E, Harrison S, Eviner VT. Grazing affects vegetation diversity and heterogeneity in California vernal pools. Ecology 2021; 102:e03295. [PMID: 33556190 DOI: 10.1002/ecy.3295] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Revised: 10/21/2020] [Accepted: 11/13/2020] [Indexed: 11/08/2022]
Abstract
Disturbance often increases local-scale (α) diversity by suppressing dominant competitors. However, widespread disturbances may also reduce biotic heterogeneity (β diversity) by making the identities and abundances of species more similar among patches. Landscape-scale (γ) diversity may also decline if disturbance-sensitive species are lost. California's vernal pool plant communities are species rich, in part because of two scales of β diversity: (1) within pools, as species composition changes with depth (referred to here as vertical β diversity), and (2) between pools, in response to dispersal limitation and variation in pool attributes (referred to here as horizontal β diversity). We asked how grazing by livestock, a common management practice, affects vernal pool plant diversity at multiple hierarchical spatial scales. In terms of abundance-weighted diversity, grazing increased α both within local pool habitat zones and at the whole-pool scale, as well as γ at the pasture scale without influencing horizontal or vertical β diversity. In terms of species richness, increases in α diversity within habitat zones and within whole pools led to small decreases in horizontal β diversity as species occupancy increased. This had a dampened effect on species richness at the γ (pasture) scale without any loss of disturbance-sensitive species. We conclude that grazing increases species richness and evenness (α) by reducing competitive dominance, without large disruptions to the critical spatial heterogeneity (β) that generates high landscape-level diversity (γ).
Collapse
Affiliation(s)
- Julia Michaels
- Department of Plant Sciences, University of California, Davis, 1210 PES, Mail Stop 1 One Shields Ave, Davis, California, 95616, USA
| | - Evan Batzer
- Department of Plant Sciences, University of California, Davis, 1210 PES, Mail Stop 1 One Shields Ave, Davis, California, 95616, USA
| | - Susan Harrison
- Department of Environmental Science & Policy, University of California, Davis, 1210 PES, Mail Stop 1 One Shields Ave, Davis, California, 95616, USA
| | - Valerie T Eviner
- Department of Plant Sciences, University of California, Davis, 1210 PES, Mail Stop 1 One Shields Ave, Davis, California, 95616, USA
| |
Collapse
|
9
|
Hutchinson RA, Fremier AK, Viers JH. Interaction of restored hydrological connectivity and herbicide suppresses dominance of a floodplain invasive species. Restor Ecol 2020. [DOI: 10.1111/rec.13240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- Rachel A. Hutchinson
- Center for Watershed Sciences University of California, Davis 1 Shields Avenue Davis CA 95616 U.S.A
- Tahoe National Forest 10811 Stockrest Springs Road, Truckee CA 96161 U.S.A
| | | | - Joshua H. Viers
- Center for Watershed Sciences University of California, Davis 1 Shields Avenue Davis CA 95616 U.S.A
- School of Engineering University of California, Merced 5200 Lake Road. Merced CA 95340 U.S.A
| |
Collapse
|
10
|
Sonnier G, Quintana‐Ascencio PF, Bohlen PJ, Fauth JE, Jenkins DG, Boughton EH. Pasture management, grazing, and fire interact to determine wetland provisioning in a subtropical agroecosystem. Ecosphere 2020. [DOI: 10.1002/ecs2.3209] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Affiliation(s)
| | - Pedro F. Quintana‐Ascencio
- Archbold Biological Station Venus Florida33960USA
- Department of Biology University of Central Florida Orlando Florida32833USA
| | - Patrick J. Bohlen
- Department of Biology University of Central Florida Orlando Florida32833USA
| | - John E. Fauth
- Department of Biology University of Central Florida Orlando Florida32833USA
| | - David G. Jenkins
- Department of Biology University of Central Florida Orlando Florida32833USA
| | | |
Collapse
|
11
|
Phethi MD, Gumbo JR. Assessment of impact of land use change on the wetland in Makhitha village, Limpopo province, South Africa. JAMBA (POTCHEFSTROOM, SOUTH AFRICA) 2019; 11:693. [PMID: 31308888 PMCID: PMC6620547 DOI: 10.4102/jamba.v11i2.693] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Accepted: 06/15/2018] [Indexed: 06/10/2023]
Abstract
Wetlands are essential for the natural function of an ecosystem, by regulating floods and remaining as a source of water supply. However, land use changes are the main forces behind wetland deterioration worldwide, including South Africa. In this article, we report on the impact of land use changes at the Makhitha wetland, Limpopo province, South Africa. The data was collected using techniques such as ecological survey, socio-economic survey and interpretation of satellite images obtained between 1978 and 2004. The study findings revealed that factors such as poverty and population growth were the driving forces behind wetland mismanagement. The cultivation of crops, grazing of livestock and road construction were the main land use activities that were practised in the wetland, which contributed to wetland deterioration, a disaster that can be mitigated. The study then recommended strategies such as environmental education, fencing and land use planning to resolve the problem of land use changes, in order to contribute to sustainable wetland management.
Collapse
Affiliation(s)
- Mpho D Phethi
- Department of Ecology and Resource Management, University of Venda, Thohoyandou, South Africa
| | - Jabulani R Gumbo
- Department of Hydrology and Water Resource Management, University of Venda, Thohoyandou, South Africa
| |
Collapse
|
12
|
Sonnier G, Bohlen PJ, Swain HM, Orzell SL, Bridges EL, Boughton EH. Assessing the success of hydrological restoration in two conservation easements within Central Florida ranchland. PLoS One 2018; 13:e0199333. [PMID: 29969464 PMCID: PMC6029772 DOI: 10.1371/journal.pone.0199333] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Accepted: 06/05/2018] [Indexed: 11/18/2022] Open
Abstract
In the USA, the United States Department of Agriculture (USDA) Natural Resource Conservation Service (NRCS) has restored millions of acres of wetlands through its Wetland Reserve Easement (WRE) programs. However, few quantitative studies have explored whether WREs have enhanced wetland hydrology and wetland plant communities. Additionally, USDA Compatible Use Permits for cattle grazing and other management practices are sometimes issued for WREs, but little is known about potential benefits/detriments of such practice on the success of wetland restoration. In this study, we tested if hydrological restoration of previously drained species poor pastures increased water depth and hydroperiod. Restoration involved plugging key ditches, adding water control structures and a berm. We also tested if hydrological restoration increased plant diversity (alpha and beta), floristic quality (using coefficient of conservatism) and increased the cover of wetland species (using species wetland status). Finally, we tested if cattle grazing had an effect on the success of restoration by comparing grazed plots to fenced plots. We studied two conservation easements (a total of 748 acres) located on semi-native pastures in central Florida, USA. We monitored vegetation using permanent transects stratified by vegetation type before (2004-2005) and after (2012) the restoration (2008). We assessed wetland hydroperiod using groundwater wells set up in 2003 and located within and outside the boundaries of these two easements. We used linear mixed models and multivariate analyses to compare vegetation and hydroperiods pre- and post-restoration. Number of flooded days increased following restoration in one of the easements, but we did not detect significant changes in hydrology in the other easement. Floristic quality, beta diversity and cover of obligate wetland species increased in both conservation easements and in most vegetation types. These vegetation changes were likely due to restoration activities since annual rainfall was not significantly different pre- and post-restoration. Cattle grazing did not have a negative or positive effect on the success of restoration, nor did we detect any positive effect of grazing on the success of restoration. Overall, our study shows that hydrological restoration can enhance wetland hydroperiod, water depth and wetland vegetation, but more resources should be allocated to short- and long-term monitoring of the restoration success.
Collapse
Affiliation(s)
- Grégory Sonnier
- Archbold Biological Station, Venus, Florida, United States of America
- * E-mail:
| | - Patrick J. Bohlen
- University of Central Florida, Orlando, Florida, United States of America
| | - Hilary M. Swain
- Archbold Biological Station, Venus, Florida, United States of America
| | - Steve L. Orzell
- Avon Park Air Force Range, Avon Park, Florida, United States of America
| | - Edwin L. Bridges
- Botanical and Ecological Consultant, Bremerton, United States of America
| | | |
Collapse
|
13
|
Faist AM, Beals SC. Invasive plant feedbacks promote alternative states in California vernal pools. Restor Ecol 2017. [DOI: 10.1111/rec.12571] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Akasha M. Faist
- Department of Ecology and Evolutionary Biology University of Colorado Boulder 334 UCB, Boulder CO 80309 U.S.A
| | - Stower C. Beals
- Department of Ecology and Evolutionary Biology University of Colorado Boulder 334 UCB, Boulder CO 80309 U.S.A
| |
Collapse
|