1
|
Braun J, Lortie CJ. Environmental filtering mediates desert ant community assembly at two spatial scales. Oecologia 2024:10.1007/s00442-024-05559-2. [PMID: 38761196 DOI: 10.1007/s00442-024-05559-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Accepted: 04/23/2024] [Indexed: 05/20/2024]
Abstract
Understanding the mechanisms that maintain species coexistence and determine patterns of community assembly are fundamental goals of ecology. Quantifying the relationship between species traits and stress gradients is a necessary step to disentangle assembly processes and to be able to predict the outcome of environmental change. We examined the hypothesis that desert ant communities are assembled by niche-based processes i.e., environmental filtering and limiting similarity. First, we used population-level morphological trait measurements to study the functional structure of ant communities along a dryland environmental stress gradient. Second, we developed species distribution models for each species to quantify large-scale climatic niche overlap between species. Body, femur, antennal scape, and head lengths were correlated with environmental gradients. Regionally, the ant community was significantly and functionally overdispersed in terms of morphological traits which suggests the importance of competition to ant community structure. Ant community assembly was also strongly influenced by environmental factors as the degree of functional trait divergence, but not phylogenetic divergence, decreased with increasing environmental stress. Thus, environmental stress likely mediates limiting similarity in these desert ecosystems. Species with lower climatic niche overlap were more dissimilar in morphological traits. This suggests that environmental filtering on ant functional traits is important at the scale of species distributions in addition to regional scales. This study shows that environmental and biotic filtering (i.e., niche-based assembly mechanisms) are jointly and non-independently structuring the ant community.
Collapse
Affiliation(s)
- Jenna Braun
- Department of Biology, York University, Toronto, ON, Canada.
| | - C J Lortie
- Department of Biology, York University, Toronto, ON, Canada
| |
Collapse
|
2
|
Larsen AE, Quandt A, Foxfoot I, Parker N, Sousa D. The effect of agricultural land retirement on pesticide use. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 896:165224. [PMID: 37392893 DOI: 10.1016/j.scitotenv.2023.165224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 06/26/2023] [Accepted: 06/28/2023] [Indexed: 07/03/2023]
Abstract
Agricultural land retirement generates risks and opportunities for ecological communities and ecosystem services. Of particular interest is the influence of retired cropland on agricultural pests and pesticides, as these uncultivated lands may directly shift the distribution of pesticide use and may serve as a source of pests and/or natural enemies for remaining active croplands. Few studies have investigated how agricultural pesticide use is impacted by land retirement. Here we couple field-level crop and pesticide data from over 200,000 field-year observations and 15 years of production in Kern County, CA, USA to investigate: 1) how much pesticide use and applied toxicity are avoided annually due to the direct effects of retirement, 2) whether surrounding retirement drives pesticide use on active cropland and what types of pesticides are most influenced, and 3) whether the effect of surrounding retirement on pesticide use is dependent on the age or revegetation cover on retired parcels. Our results suggest about 100 kha are idle in any given year, which equates to about 1.3-3 M kg of pesticide active ingredients foregone. We also find retired lands lead to a small increase in total pesticide use on nearby active lands even after controlling for a combination of crop-, farmer-, region- and year-specific heterogeneity. More specifically, the results suggest a 10 % increase in retired lands nearby results in about a 0.6 % increase in pesticides, with the effect sizes increasing as a function of the duration of continuous fallowing, but decreasing or even reversing sign at high levels of revegetation cover. Our results suggest increasingly prevalent agricultural land retirement can shift the distribution of pesticides based on what crops are retired and what active crops remain nearby.
Collapse
Affiliation(s)
- Ashley E Larsen
- Bren School of Environmental Science & Management, UC Santa Barbara, United States of America.
| | - Amy Quandt
- Department of Geography, San Diego State University, United States of America
| | - Iris Foxfoot
- Bren School of Environmental Science & Management, UC Santa Barbara, United States of America
| | - Nicol Parker
- Bren School of Environmental Science & Management, UC Santa Barbara, United States of America
| | - Daniel Sousa
- Department of Geography, San Diego State University, United States of America
| |
Collapse
|
3
|
Espinoza V, Bernacchi LA, Eriksson M, Schiller A, Hayden A, Viers JH. From fallow ground to common ground: Perspectives on future land uses in the San Joaquin valley under sustainable groundwater management. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 333:117226. [PMID: 36758414 DOI: 10.1016/j.jenvman.2023.117226] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 12/15/2022] [Accepted: 01/03/2023] [Indexed: 06/18/2023]
Abstract
Agriculture dominates California's San Joaquin Valley with over five million acres of farmland produces 400 different commodities ranging from nuts, tree fruits, vines, and row crops. During dry years agricultural production in the San Joaquin Valley uses about 53% of total applied water in the state. Implementation of California's Sustainable Groundwater Management Act (SGMA) will restrict groundwater pumping, likely reducing irrigated agricultural land use resulting in conversion to alternative land uses. To promote collaborative and inclusive efforts to repurpose agricultural land, California's legislature established a funding program administered by the Department of Conservation, the Multibenefit Land Repurposing Program (MLRP), in 2021. To ensure that land repurposing plans under the MLRP and SGMA represent San Joaquin Valley community needs this paper examines public perceptions of future land uses under SGMA through a phone survey. Respondents (n = 197) were recruited through a stratified random sample of mobile numbers registered within communities in the San Joaquin Valley classified as disadvantaged communities (DACs) (n = 32). Our results show that most respondents were somewhat (33%) or not at all (54%) familiar with SGMA, highlighting the need for outreach efforts to overcome barriers to representation, translation, and education about future water and land use decisions. Survey respondents identified secure water supplies (e.g., groundwater recharge) (35%) and less-water intensive agriculture (27%) as their top land use priorities to address groundwater overdraft under SGMA, indicating that the status quo for land use is preferred to alternative land uses. Preference for maintaining agriculture as primary land use (27%), we correlated with agricultural identity and lack of interest in community or global benefits such as schools and climate change mitigation. The findings from this study underscore the local variability in land use values and the importance to engaging local communities in land use decision-making, especially as they relate to changing current practices toward a more climate-resilient but agriculturally productive future with less land and less water.
Collapse
Affiliation(s)
- Vicky Espinoza
- University of California Merced, School of Engineering, Merced, CA, USA; The Nature Conservancy, 555 Capitol Avenue, Ste 1290, Sacramento, CA, 95814, USA.
| | - Leigh A Bernacchi
- University of California Merced, School of Engineering, Merced, CA, USA; Secure Water Future, University of California Merced, Merced, CA, USA
| | - Max Eriksson
- Secure Water Future, University of California Merced, Merced, CA, USA; Vrije Universiteit Brussel. Brussel School of Governance. Centre for Environment, Economy and Energy, USA
| | - Anna Schiller
- Environmental Defense Fund, 123 Mission Street, San Francisco, CA, USA
| | - Ann Hayden
- Environmental Defense Fund, 123 Mission Street, San Francisco, CA, USA
| | - Joshua H Viers
- University of California Merced, School of Engineering, Merced, CA, USA; Secure Water Future, University of California Merced, Merced, CA, USA.
| |
Collapse
|
4
|
Foundation plant species provide resilience and microclimatic heterogeneity in drylands. Sci Rep 2022; 12:18005. [PMID: 36289265 PMCID: PMC9606251 DOI: 10.1038/s41598-022-22579-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Accepted: 10/17/2022] [Indexed: 01/24/2023] Open
Abstract
Climate change profoundly influences plants and animals in all ecosystems including drylands such as semi-arid and arid scrublands and grasslands. At the peak of an extended megadrought in the Southwestern USA, the microclimatic refuges provided by foundation plant species and through associated vegetation were examined. Shrubs and open interstitial spaces without a canopy but with annual plants were instrumented in 2016 and the wet season of 2017 in the central drylands of California. In both years and all seasons tested, vegetation significantly mediated fine-scale near-surface air temperature and relative soil moisture content-defined here as microclimate. The foundation species with other vegetation provided the most significant thermal refuge potential capacity for other plants and animals, but there was variation by growing season. Soil moisture content was frequently increased by the direct canopy effects of shrubs. This evidence suggests that the climate many plants and animals experience, even during an extended megadrought, is mediated by the local plants in highly impacted drylands with anthropogenic disturbance and significant water-induced challenges. Foundation species such as shrubs in drylands function as a potent starting point in examining the ecological relevance of climate at scales germane to many species locally. An ecological framework for climate resilience using shrubs will improve conservation and restoration planning in drylands.
Collapse
|
5
|
Lortie CJ, Filazzola A, Brown C, Lucero J, Zuliani M, Ghazian N, Haas S, Owen M, Butterfield HS, Nix E, Westphal M. Facilitation promotes plant invasions and indirect negative interactions. OIKOS 2021. [DOI: 10.1111/oik.08443] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
| | | | | | - Jacob Lucero
- Dept of Biology, York Univ. Toronto ON Canada
- Division of Biological Sciences, Univ. of Montana Missoula USA
| | | | | | | | - Malory Owen
- Dept of Biology, York Univ. Toronto ON Canada
| | | | | | | |
Collapse
|
6
|
Miguel MF, Butterfield HS, Lortie CJ. A meta-analysis contrasting active versus passive restoration practices in dryland agricultural ecosystems. PeerJ 2020; 8:e10428. [PMID: 33282566 PMCID: PMC7690292 DOI: 10.7717/peerj.10428] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Accepted: 11/03/2020] [Indexed: 11/20/2022] Open
Abstract
Restoration of agricultural drylands globally, here farmlands and grazing lands, is a priority for ecosystem function and biodiversity preservation. Natural areas in drylands are recognized as biodiversity hotspots and face continued human impacts. Global water shortages are driving increased agricultural land retirement providing the opportunity to reclaim some of these lands for natural habitat. We used meta-analysis to contrast different classes of dryland restoration practices. All interventions were categorized as active and passive for the analyses of efficacy in dryland agricultural ecosystems. We evaluated the impact of 19 specific restoration practices from 42 studies on soil, plant, animal, and general habitat targets across 16 countries, for a total of 1,427 independent observations. Passive vegetation restoration and grazing exclusion led to net positive restoration outcomes. Passive restoration practices were more variable and less effective than active restoration practices. Furthermore, passive soil restoration led to net negative restoration outcomes. Active restoration practices consistently led to positive outcomes for soil, plant, and habitat targets. Water supplementation was the most effective restoration practice. These findings suggest that active interventions are necessary and critical in most instances for dryland agricultural ecosystems likely because of severe anthropogenic pressures and concurrent environmental stressors-both past and present.
Collapse
Affiliation(s)
- M. Florencia Miguel
- Consejo Nacional de Investigaciones Científicas y Técnicas, Mendoza, Argentina
| | | | - Christopher J. Lortie
- National Center for Ecological Analysis and Synthesis (NCEAS), Santa Barbara, CA, USA
- Department of Biology, York University, Toronto, ON, Canada
| |
Collapse
|
7
|
Lucero JE, Seifan M, Callaway RM, Lortie CJ. Positive associations with native shrubs are intense and important for an exotic invader but not the native annual community across an aridity gradient. DIVERS DISTRIB 2020. [DOI: 10.1111/ddi.13111] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Affiliation(s)
- Jacob E. Lucero
- Department of Biology York University Toronto Ontario Canada
| | - Merav Seifan
- Mitrani Department of Desert Ecology Swiss Institute for Dryland Environmental and Energy Research The Jacob Blaustein Institutes for Desert Research Ben‐Gurion University of the Negev Midreshet Ben‐Gurion Israel
| | - Ragan M. Callaway
- Division of Biological Sciences and the Institute on Ecosystems University of Montana Missoula MT USA
| | | |
Collapse
|
8
|
Statham MJ, Bean WT, Alexander N, Westphal MF, Sacks BN. Historical Population Size Change and Differentiation of Relict Populations of the Endangered Giant Kangaroo Rat. J Hered 2019; 110:548-558. [PMID: 30715400 DOI: 10.1093/jhered/esz006] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Accepted: 01/24/2019] [Indexed: 12/30/2022] Open
Abstract
From a conservation management perspective it is important to understand how genetic diversity is partitioned across a species' range, including 1) identification of evolutionarily distinct units versus those recently isolated through anthropogenic activities and 2) the relative genetic contributions among components of fragmented (meta)populations. To address these questions, we investigated the phylogeography and metapopulation structure among relict populations of the endangered giant kangaroo rat (Dipodomys ingens) in the highly altered San Joaquin Desert Ecosystem. This keystone species underwent a ~97% range reduction over the past century, resulting in a current range that is highly fragmented, with 2 dominant northern and southern populations occurring 150 km apart. We sequenced >800 bp of mitochondrial DNA and genotyped 17 nuclear microsatellites in >275 D. ingens to assess the evolutionary relationship of these populations as well as the genetic structure within the northern metapopulation. A Bayesian Skyline Plot indicated that the species experienced a demographic expansion toward the end of the Pleistocene, with a recent population decline. Northern and southern D. ingens split 1857-13 443 years ago, prior to the massive conversion of the San Joaquin Valley to irrigated agriculture. We recommend that the northern and southern populations of D. ingens be re-classified as distinct population segments under the United States Endangered Species Act. We also observed population structure and asymmetrical migration within northern D. ingens where the Tumey Hills acted as a source contributing gene flow to all peripheral populations. This emphasized the importance of this location in the conservation of the metapopulation as a whole.
Collapse
Affiliation(s)
- Mark J Statham
- Mammalian Ecology and Conservation Unit, Veterinary Genetics Laboratory, University of California, Davis, CA.,Department of Population Health and Reproduction, School of Veterinary Medicine, University of California, Davis, California, CA
| | - William T Bean
- Department of Wildlife, Humboldt State University, Arcata, CA
| | - Nathan Alexander
- Department of Natural Resources and Environmental Sciences, University of Illinois, Urbana, IL
| | | | - Benjamin N Sacks
- Mammalian Ecology and Conservation Unit, Veterinary Genetics Laboratory, University of California, Davis, CA.,Department of Population Health and Reproduction, School of Veterinary Medicine, University of California, Davis, California, CA
| |
Collapse
|
9
|
Bourque K, Schiller A, Loyola Angosto C, McPhail L, Bagnasco W, Ayres A, Larsen A. Balancing agricultural production, groundwater management, and biodiversity goals: A multi-benefit optimization model of agriculture in Kern County, California. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 670:865-875. [PMID: 30921719 DOI: 10.1016/j.scitotenv.2019.03.197] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2018] [Revised: 03/12/2019] [Accepted: 03/13/2019] [Indexed: 06/09/2023]
Abstract
As surface water becomes scarcer and precipitation more variable in a warmer climate, reliance on groundwater reserves for agricultural use is expected to increase. Where efforts to achieve sustainable groundwater management require reductions in aggregate extraction, some of these reductions will entail a decline in agricultural production. However, the degree to which water conservation and other environmental priorities conflict with agricultural production depends, in part, on the spatial configuration of land-use decisions. We explore how to spatially configure groundwater recharge projects to achieve groundwater recharge targets and preserve ecologically important habitat at the least cost. We conduct a field-level analysis for all fields in Kern County, California, the largest crop-producing county in California (and the United States). Results demonstrate that fields selected for cost-effective land retirement can achieve groundwater recharge targets and simultaneously contribute to biodiversity goals via endangered species habitat conservation. However, increasing the amount of habitat conserved raises costs significantly. We discuss conservation actions, economic incentives, and policies that can be leveraged to meet regional biodiversity goals while preserving the economic vitality of agricultural communities. More broadly, this work also provides a proof-of-concept for applying the conservation planning tool, Marxan, to promote efficient allocation of land uses in the face of increasing water resource scarcity and biodiversity threats.
Collapse
Affiliation(s)
- Kelly Bourque
- Bren School of Environmental Science and Management, University of California, Bren Hall, 2400, Santa Barbara, CA, United States; Goleta Water District, 4699 Hollister Ave, Santa Barbara, CA, United States.
| | - Anna Schiller
- Bren School of Environmental Science and Management, University of California, Bren Hall, 2400, Santa Barbara, CA, United States; Environmental Defense Fund, California Habitat Exchange & Western Water, 123 Mission Street, San Francisco, CA, United States.
| | - Cristóbal Loyola Angosto
- Bren School of Environmental Science and Management, University of California, Bren Hall, 2400, Santa Barbara, CA, United States; Quantis International, 240 Commercial Street, Boston, MA, United States.
| | - Lindsay McPhail
- Department of Agricultural and Resource Economics, University of California Davis, 1 Shields Avenue, Davis, CA, United States.
| | - Wendy Bagnasco
- Bren School of Environmental Science and Management, University of California, Bren Hall, 2400, Santa Barbara, CA, United States; Caesars Entertainment Corporation, 1 Caesars Palace Drive, Las Vegas, NV, United States.
| | - Andrew Ayres
- Bren School of Environmental Science and Management, University of California, Bren Hall, 2400, Santa Barbara, CA, United States; Environmental Defense Fund, Office of the Chief Economist, 123 Mission Street, San Francisco, CA, United States.
| | - Ashley Larsen
- Bren School of Environmental Science and Management, University of California, Bren Hall, 2400, Santa Barbara, CA, United States.
| |
Collapse
|
10
|
Lucero JE, Noble T, Haas S, Westphal M, Butterfield H, Lortie CJ. The dark side of facilitation: native shrubs facilitate exotic annuals more strongly than native annuals. NEOBIOTA 2019. [DOI: 10.3897/neobiota.44.33771] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Positive interactions enhance biodiversity and ecosystem function, but can also exacerbate biological invasions. Facilitation of exotic invaders by exotic foundation species (invasional meltdown) has been studied extensively, but facilitation of exotic invaders by native foundation species has attracted less attention. Specifically, very few studies have examined the extent that native foundation species facilitate native and exotic competitors. Understanding the processes that mediate interactions between native and exotic species can help explain, predict, and improve management of biological invasions. Here, we examined the effects of native foundation shrubs on the relative abundance of the annual plant community – including native and exotic taxa – from 2015–2018 in a desert ecosystem at Carrizo Plain National Monument, California, USA (elevation: 723 m). Shrub effects varied by year and by the identity of annual species, but shrubs consistently enhanced the abundance of the annual plant community and facilitated both native (n=17 species) and exotic (n=4 species) taxa. However, at the provenance level, exotic annuals were facilitated 2.75 times stronger in abundance than native annuals, and exotic annuals were always more abundant than natives both near and away from shrubs. Our study reaffirms facilitation as an important process in the organisation of plant communities and confirms that both native and exotic species can form positive associations with native foundation species. However, facilitation by native foundation species can exacerbate biological invasions by increasing the local abundance of exotic invaders. Thus, the force of facilitation can have a dark side relevant to ecosystem function and management.
Collapse
|
11
|
Distribution, fine-scale subdivision, and population size of San Joaquin kit foxes in the Ciervo-Panoche Natural Area, California. CONSERV GENET 2019. [DOI: 10.1007/s10592-018-1122-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
12
|
Stewart JAE, Butterfield HS, Richmond JQ, Germano DJ, Westphal MF, Tennant EN, Sinervo B. Habitat restoration opportunities, climatic niche contraction, and conservation biogeography in California's San Joaquin Desert. PLoS One 2019; 14:e0210766. [PMID: 30645624 PMCID: PMC6333358 DOI: 10.1371/journal.pone.0210766] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2018] [Accepted: 12/31/2018] [Indexed: 12/03/2022] Open
Abstract
A recent global trend toward retirement of farmland presents opportunities to reclaim habitat for threatened and endangered species. We examine habitat restoration opportunities in one of the world's most converted landscapes, California's San Joaquin Desert (SJD). Despite the presence of 35 threatened and endangered species, agricultural expansion continues to drive habitat loss in the SJD, even as marginal farmland is retired. Over the next decades a combination of factors, including salinization, climate change, and historical groundwater overdraft, are projected to lead to the retirement of more than 2,000 km2 of farmland in the SJD. To promote strategic habitat protection and restoration, we conducted a quantitative assessment of habitat loss and fragmentation, habitat suitability, climatic niche stability, climate change impacts, habitat protection, and reintroduction opportunities for an umbrella species of the SJD, the endangered blunt-nosed leopard lizard (Gambelia sila). We use our suitability models, in conjunction with modern and historical land use maps, to estimate the historical and modern rate of habitat loss to development. The estimated amount of habitat lost since the species became protected under endangered species law in 1967 is greater than the total amount of habitat currently protected through public ownership and conservation easement. We document climatic niche contraction and associated range contraction away from the more mesic margins of the species' historical distribution, driven by the anthropogenic introduction of exotic grasses and forbs. The impact of exotic species on G. sila range dynamics appears to be still unfolding. Finally, we use NASA fallowed area maps to identify 610 km2 of fallowed or retired agricultural land with high potential to again serve as habitat. We discuss conservation strategies in light of the potential for habitat restoration and multiple drivers of ongoing and historical habitat loss.
Collapse
Affiliation(s)
- Joseph A. E. Stewart
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, United States of America
- Institute for the Study of Ecological and Evolutionary Climate Impacts, University of California, Santa Cruz, CA, United States of America
| | | | | | - David J. Germano
- Department of Biology, California State University Bakersfield, Bakersfield, CA, United States of America
| | | | - Erin N. Tennant
- Lands Unit, Central Region, California Department of Fish and Wildlife, Fresno, CA, United States of America
| | - Barry Sinervo
- Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA, United States of America
- Institute for the Study of Ecological and Evolutionary Climate Impacts, University of California, Santa Cruz, CA, United States of America
| |
Collapse
|