Research

My research interests are how environmental variation (spatial and temporal) produce patterns of biodiversity and functioning in communities. I approach this within a metacommunity framework whereby local (e.g., disturbances, competition, and predation) and regional (e.g., dispersal) processes contribute to community dynamics. In addition, I am interested in the movement of materials across the land-water interface in both time and space and its consequences on communities. Recently, this research has expanded to examine spatial patterns of diversity along latitudinal gradients and how species traits influence those patterns. Further, my research also links ecological principles with conservation topics, including eutrophication, restoration, species invasions, and climate change. This research is conducted in seasonal freshwater ecosystems, including California vernal pools and rock pools. Here is a sampling of the research currently being conducted in my lab:

See Poster made for the 2016 Arboretum Earth Day event

Latitudinal Diversity Gradient Projects
One of oldest documented ecological pattern is the increase in diversity as you head towards the tropics from higher latitudes. In California vernal pool invertebrates, the opposite pattern exists (Kneitel 2016). Climate-driven habitat size appears to be the primary factor influencing the latitudinal diversity gradient at different spatial scales. Species traits also interact with the environment to affect spatial diversity patterns (Kneitel 2018). We are currently expanding on this previous research to address:
1. Plant diversity and trait patterns along the latitudinal gradient (in collaboration with Jennifer Buck-Diaz, CNPS)
2. Land use effects on spatial diversity patterns for animals and plants (MS student Hannah Savage)
3. Comparison of natural, restored, and constructed pools along the latitudinal gradient (MS student Sean O'Brien)

Vernal Pool Ecosystems (funded projects):
Fulbright Scholar Program: A Synthesis of Seasonal Wetland Ecology in Mediterranean Climate Regions (2017-2018)
Abstract My Fulbright Scholar plan is to conduct research (with Leon Blaustein) and teach a graduate-level course at the University of Haifa in Israel. The research will focus on synthesizing our current knowledge of seasonal wetlands in Mediterranean climate regions by conducting a parallel experiment in Israel and conducting a meta-analysis of biodiversity patterns and environmental variables from each of the 5 Mediterranean climate regions. The course, Community Metrics, will complement Haifa University’s current graduate-level curriculum with a comprehensive survey of recent approaches to understanding ecological communities. This opportunity will lay a foundation for a fruitful academic relationship and strengthen cultural ties among researchers, students, departments, and universities.

You can check out my Fulbright Scholar Blog
CSUS story on Fulbright Award
My Israel and Morocco species list

CSU-COAST: Chemical tracers of human activities and ecological associations in California vernal pools (2017-2018)
With PI Justin Miller-Schulz (CSUS, Dept of Chemistry)
Abstract The effects of anthropogenic activities, such as pollutants, on water quality are important to assess because they can have extensive effects on human and ecosystem health. Contaminants of Emerging Concern (CECs) are a broad class of compounds that include pharmaceuticals, personal care products, illicit drugs, herbicides and pesticides. Their “emerging concern” is indicated by the fact that measurements are being made but they are not currently regulated. Many freshwater ecosystems in California, such as wetlands, have not been assessed for CECs and its association with ecosystem health. Our proposal will address this gap by quantifying CECs in California vernal pools under different land use practices. Vernal pools are seasonal wetlands or ponds that support numerous endangered and threatened species. Vernal pools represent greatly reduced habitat (< 10% remain), and this remaining habitat is found in a matrix of urban and agricultural development. Consequently, vernal pools may be especially susceptible as a recipient of CECs. In addition, vernal pools represent the upper watershed of the Central Valley and the Sacramento River, and as such are hydrologically connected to the Sacramento-San Joaquin River Delta and San Francisco Bay. Assessing the relevant sources of water quality impact on vernal pool ecosystems through CEC measurement will also allow assessment of the relevance of specific sources on coastal ecosystem health due to this hydrological connection. The research proposed by PIs Miller-Schulze and Kneitel will be focused on collecting preliminary data on CEC concentrations and associate them with local land use, vernal pool size characteristics, water physico-chemistry (e.g., phosphates, nitrates, conductivity), and aquatic invertebrate and plant density and diversity. Graduate and undergraduate students from Departments of Chemistry and Biological Sciences will be included in this research, interact collaboratively, and disseminate results.

NSF-DEB RUI: Spatial and Temporal Subsidies in Seasonal Environments (2014 - 2016)
Abstract Seasonal variation in precipitation and temperature can result in aquatic and terrestrial habitat occurring sequentially at a single location in the landscape. Examples of this occur worldwide and include seasonal wetlands, river-floodplains, and temporary ponds. Ecological research and management tend to focus on the aquatic or terrestrial phases of these ecosystems. The researcher will test novel hypotheses regarding interactions among these phases during the seasonal cycling of inundation and desiccation, via temporal subsidies. This research will use experimental and observational approaches in the California vernal pool ecosystem, a greatly reduced habitat that supports high species diversity and endemism in both the aquatic and terrestrial phases. Other factors that are known to affect aquatic and terrestrial communities—nutrient pollution (aquatic), inundation length (aquatic), and thatch depth (terrestrial)—will be examined within this framework. Variables, including water characteristics, diversity of plants (aquatic and terrestrial) and invertebrates (aquatic), will be measured within and among seasons and years.

Seasonal wetlands worldwide support high levels of endemism and are threatened by widespread habitat loss and climate change. This research provides new insights to the spatiotemporal interactions among aquatic and terrestrial communities and contributes novel approaches and concepts to basic and applied ecology. The project supports undergraduate students, emphasizing the inclusion of students from underrepresented groups. The project also involves researchers from other institutions and provides K-12 education experiences. The study system and research results are to be included in ecology and quantitative courses where students work on critical and cutting-edge questions. Because California vernal pools are a conservation priority, research results will be disseminated to State and Federal agencies.

*Recent poster presentation on this research: poster

Other California vernal pool projects (also see Graduate Student webpage):

Species diversity (alpha, beta, gamma) patterns along a latitudinal gradient
The role of environmental and spatial processes on diversity patterns in natural and restored vernal pools, including the role of connectivity
The effects of water quality and eutrophication
Top-down and bottom-up effects
Bacteria functional diversity as a function of pool characteristics
Land use effects on eutrophication and species composition
Climate change (temperature and hydroperiod) effects on community composition

Rock Pool Ecosystems (funded projects):
BoR/USFWS CVPCP: Central Valley Project Conservation Program and Central Valley Project Improvement Act Habitat Restoration Program (2016-2021)
With Doug Bell (East Bay Regional Park District), John Vollmar, and Brent Helm. This funds research on the ecology of Branchinecta longiantenna.

Other rock pool projects:
1. Spatial and temporal patterns of biodiversity, including the environmental determinants of ecosystem function, community structure, and endangered species (B. lynchi and B. longiantenna) distributions
2. Metacommunity ecology and alternative stable states in rock pool communities
3. Metapopulation ecology of Branchinecta lynchi

Bushy Lake Conceptual Restoration Plan, Sacramento County (2020-23) funded by State of California Wildlife Conservation Board (Michelle Stevens, CSUS Environmental Studies, P): We are beginning to monitor Bushy Lake with the product being a restoration plan. Dr. Tim Davidson and I will lead monthly aquatic habitat surveys of water quality, algae, crustaceans, and aquatic insects in Bushy Lake to quantify seasonal dynamics.

Collaborators:
- Jennifer Buck-Diaz (CNPS) Latitudinal Plant Diversity in California Vernal Pools
- Leon Blaustein (University of Haifa) A Synthesis of Seasonal Wetland Ecology in Mediterranean Climate Regions (Fulbright Scholar Program funded)
- Laila Rhazi and Mohammed El Medihi (University of Mohammed V- Rabat) Temporary Pond Ecology (Fulbright Scholar Program funded)
- Justin Miller-Schulz (CSUS, Dept of Chemistry): Chemical tracers of human activities and ecological associations in California vernal pools (CSU-COAST funded)
- Doug Bell (East Bay Regional Park District): Longhorn Fairy Shrimp Habitat Research in Contra Costa and Alameda Counties (BoR/USFWS funded)
- Don Yee (USM): Treehole ecosystem dynamics
- Sharon Collinge (UColorado): Aquatic and terrestrial phase interactions in vernal pool ecosystems
- Enid Gonzalez-Orta (CSUS): Bacteria functional diversity in vernal pools
- I gratefully acknowledge Westervelt Ecological Services for their support of students and use of their managed lands