You are hereResearch Needs
Although some buffelgrass research has been completed, there is still a lack of scientific information to support and evaluate buffelgrass control methods, restoration after treatment, or adaptation in the event that control is not possible and fire-resistant desert becomes flammable grassland.
A working list of buffelgrass research needs is provided below and additional information may be referenced in Appendix 6 of the Southern Arizona Buffelgrass Strategic Plan.
Biodiversity and Ecosystems
- Mechanism of invasion, competition and spread
- Level and type of disturbance that encourages spread?
- What are the thresholds?
- Spread and niche models for different strains of buffelgrass that take into account landscape structure, pathways of dispersal, and climate variability and change (Strategic Plan)
- Ecological, physical or genetic processes that contribute to plant invasiveness
- Impacts of buffelgrass on native plant communities
- How and to what extent is buffelgrass affecting specific species; some work on columnar cacti (Morales-Romero), palo verdes (Elits – Huxman lab), cottontop (Jason Stevens)
- What species are in direct competition and what resources are they competing for and to what degree? (rate, depth and quantity of water uptake)
- Growth rates of saguaros and other key flora at different buffelgrass densities.
- EX. Introduce buffelgrass into an area and see what gets displaced, stressed, changes in nutrient and water availability, changes in wildlife use….
- What are the changes in community structure (light, height, density, etc.) and composition (richness, diversity) and what are the implications
- Investigate relationship between buffelgrass (different strains) traits and the abiotic and physical environment to determine range limits and community composition
- Use of buffelgrass by native fauna (insects, small mammals, birds, herps)
- What is the forage potential for natives, structure and composition for shelter (favorable or not), habitat implications
- Is there a density dependent relationship?
- Desert fires fueled by buffelgrass
- What is going to happen to our ecosystem; infer some from red brome fires (Cave Creek – Tonto NF, Mother’s Day- Saguaro NP)
- What are the below ground effects
- Based on fire behavior models (under investigation by McDonald-McPherson) what #/acre, fuel spatial configuration, thresholds will carry fire
- Fire behavior and effects – of natives in buffelgrass stands
- Post buffelgrass fire implications on communities, recovery, soils, composition
- Post-buffelgrass fire restoration (BAER)
- Does fire kill the seed? Bury seeds at different depths.
- Fuel loads at different densities and stages of decomposition
- Buffelgrass response (establishment, persistence, spread, etc.) to climate change
- change in precipitation and temperature regimes,
- CO2, GH gases, inc/dec levels of N, K, Phosphorus
- Are certain microbes in soil favoring the establishment and/or persistence of non-natives
- Investigate relationship of soil nutrients, soil microbes, and buffelgrass
- Changes in soil properties due to buffelgrass infestations
- Is there an association of buffelgrass or other non-natives with N-fixators?
- Impacts on biological crusts
- At what point are the seeds viable
- How drought tolerant are the seeds
- How long can seeds persist in the soil and still be viable? Can seeds be dated
- How large (mass) is the seed bank under buffelgrass stands of different ages
- Herbicide efficacy trials
- Investigate other herbicides or combinations of herbicides and adjuvants that would extend the window of treatment on buffelgrass
- Phenological models (Strategic Plan)
- Is there a relationship between age of infestation, density,…that influences number of treatments to exhaust seed bank
- Biological controls
- Decomposition of grass sprayed vs pulled vs senescent
- To what extent do treated buffelgrass patches need restoration. (Strategic Plan)
- What are the thresholds or indicators that more active restoration is necessary
- What methods and techniques are effective
Mapping and Monitoring
- Effective techniques for mapping buffelgrass at landscape scale
- Investigate different new imagery for detection (build on Olsson’s findings)
- Helicopter mapping (digital sketch mapping) and ground truthing methods
- Map at higher elevations
- Economic impacts of buffelgrass
- How much does Sonoran Desert contribute to the economy and what are the potential and real changes that buffelgrass can have on economics