The interaction of rangeland management and environmental conditions in regulating forage quality - quantity and other ecosystem services

The interaction of rangeland management and environmental conditions in regulating forage quality - quantity and other ecosystem services

Summary

With substantial input from a broad group of stakeholders, the database format has been completed (with the expectation that it will be periodically updated to accommodate new types of management practices and dataset structures). The database and its web interface are currently under construction. This is later than scheduled, due to the technical challenges associated with designing a database to accommodate the diverse management types and response factors incorporated into the project. While the database professionals have been researching the best approaches to designing the database, the research team has focused on field sampling so that the data can be incorporated into the database as soon as it is ready.

On-ranch sampling of the effects of management on multiple ecosystem services has continued and has been used to fine-tune the draft of the monitoring protocols. The severe drought that California has experienced for the past three years (the duration of this project) has provided a unique opportunity to study one of the top priorities of land managers – a better understanding of drought responses and management. To take advantage of this opportunity (and by necessity, given the weather conditions during the project), sampling has focused on how environmental and management conditions influence the effect of drought on: plant production, plant species composition, plant cover, erosion, and water infiltration and storage. Depending on precipitation for the remainder of this 2014-15 growing season, we will either continue sampling for the site-dependent impacts of management on drought or will transition to assess how interactions between management and environmental conditions determine the timing and extent of recovery from drought (in terms of plant production and cover, species composition, and soil conditions). Based on meetings with stakeholders, we sampled more sites but measured fewer ecosystem services to assess drought responses.

Objectives/Performance Targets

Our objectives and performance targets are summarized below, including the status (and projected dates of completion) for each of these. (These new dates assume approval of the no-cost extension, which is being submitted separately, as requested).

 Objective 1: Assess how local to regional differences in environmental conditions determine:

1. Site-specific potential to provide multiple ecosystem services.
2. The impacts of range management practices on suites of ecosystem services, and which practices are most effective for a given service at a given site.
3. In addition to the original sub-objectives (1-1, 1-2), we have also added the following: Determine the effects of site environmental conditions and management practices on the response of vegetation production, cover, and composition to drought and recovery after drought. Soil responses to drought have been focused on erosion, and to a lesser extent, water infiltration and storage.

Performance targets related to this objective:

1. Develop a web database of management practices and their impacts on ecosystem services.

While we had anticipated the database being public by now, this likely will not occur until fall 2015 because the development of the database has been more complex than we had initially anticipated. Complexities are due to the multiple types of services being measured, the multiple measurement approaches for each of these services, the diversity of management approaches, and the multiple environmental factors that are determining these services (with focal services, measures, management practices, and environmental factors differing across projects so that most of them are not directly comparable without calibration). The database structure has been determined, and the database and web interface are being developed in collaboration with database developers and GIS professionals at the University of California’s Division of Agriculture and Natural Resources (the group that runs UC Cooperative Extension), which will ensure a web-host for this database over the long-term.

On the advice of the database professionals, we are focused on collecting data, which will be incorporated into the database once it is completed (rather than first building the database and then focusing on collecting data, as was originally planned). We have been sampling ranches for the effects of local environmental conditions and management practices on multiple ecosystem services. Particularly in this past growing season (2013-14), we have focused on plant production, cover and plant species composition, as well as erosion events, due to the severe drought in California. Key findings are summarized in the “accomplishments/ milestones” section.

A key field activity is needed to allow the database to compare and summarize across diverse measurement approaches: field trials to calibrate across multiple measures for a given service. This was supposed to occur over the past two field seasons but has been delayed due to the drought in California (we have assumed the severe drought conditions may not provide the most reliable calibrations across multiple measures). Assuming we get “normal” rainfall in the upcoming months, we will deploy these calibration measures this season and next season.

2. Develop a “Measuring ecosystem services handbook” and “toolkit for measuring ecosystem services.” Based on workshops and surveys of stakeholders, we have decided to revise the initial plans. Rather than one set of ecosystem service measurements, we have divided them into two. The first set will be a more comprehensive, quantitative set of measurements, appropriate for research, official monitoring programs, and managers who are enthusiastic to monitor the impacts of their practices. We are fine-tuning a draft of this currently and are using this as a template to sample our field sites. We are adjusting the handbook draft in response to user feedback and will convene stakeholders to comment on this draft during the summer of 2015. These will include standardized, repeatable measures, similar to those originally proposed (e.g. infiltrometers to determine infiltration, cohesion testers to determine erosion potential, lab tests of soil to determine soil organic matter and water holding capacity, etc.). The second set of protocols is more informal, providing a quick, qualitative assessment by managers. For example, rather than official determination of invasive species cover, they would assess invasive cover by selecting the closest match in cover from five to eight photos depicting different levels of invasion (this would calibrate across individual assessors). The same type of approach will occur for production, visible erosion events, and visible runoff (lack of water infiltration).

3. Recruit managers to participate in the database. This has been an on-going, successful effort. We have provided stakeholder feedback sessions, as well as talks and posters highlighting the project at a number of venues, and write-ups in newsletters including: California Rangeland Conservation Coalition, California Climate and Agriculture Network, Cooperative Extension field days, as well as to a number of conservation groups utilizing grazing as a management tool (California Native Grassland Association, California Invasive Plant Council).

Objective 2: Improve the effectiveness of range management by enhancing the availability of information for developing management plans.

The initial two steps are described above: developing the database and the measuring services handbook and toolkit. The other two performance targets will be provided towards the end of the project, once the work is synthesized.

1. Develop an on-line decision support tool for managing multiple services.
2. Develop regional maps of the distribution of multiple services.

Accomplishments/Milestones

As stated above, the major accomplishments include:

1. Fine-tuning the priority ecosystem services, measurements, environmental conditions, and management practices to include in the database.
2. Recruiting agencies, nonprofits, and individual ranchers to participate in the database project.
3. Field sampling of ecosystem services across diverse environmental conditions and management approaches on California’s rangelands.
4. Developing the quantitative ecosystem measures handbook (qualitative one is still in development).

Data is still being analyzed, but trends from measurements and collected datasets are emerging:

– Drought conditions, in general, have increased the prevalence of native perennial grasses and decreased the prevalence of noxious rangeland weeds such as goatgrass and medusa head.

– Early spring grazing decreases the aboveground biomass of naturalized annuals, such as Avena sp. and Bromus sp., thus decreasing their water use and increasing soil moisture. This provides more moisture reserves, increasing prevalence of late-season weeds such as medusa head and goatgrass. However, during springs with low rainfall, the lack of soil moisture reserves limits regrowth after spring grazing, leading to very low RDM and seed production of the advantageous forage species (e.g. Avena, Bromus, Lolium), as well as the noxious weeds.

– Across sites, response of vegetation composition to the 2013-14 drought largely fell within three categories:

1. Early season flush of annual grasses which died off, leaving relatively little live vegetation until the rains in February, when forbs and legumes dominated production.
2. Early season flush of annual grasses which survived in stunted form, then grew profusely after February rains.
3. Little germination until February, when annual grasses germinated and dominated (in restoration sites, established perennials survived during this dry period).

We are still assessing site conditions that may account for these different drought responses. End of season production did not differ from the past two years (which were also dry years).

Impacts and Contributions/Outcomes

The main impacts of this project will occur towards the end when the database and decision support tool are deployed. But current outreach efforts to gain stakeholder input and participation have initiated important discussions about the importance of multiple ecosystem services and realistic monitoring protocols across a wide group of stakeholders.

Collaborators: