FRC Funds Chico State to Research Z-Grass Restoration Strategies in Fall River
In 2013 the Fall River Conservancy partnered with the Chico State Department of Biological Sciences to discover new methodologies of restoring Zannicheliia palustris (Z-grass) in the Fall River. Lead researcher Dr. Kristina Schierenbeck led a team of researchers on year one of a three-year study to experiment with new re-vegetation methodologies, and also assess the benefits that Z-grass provides for bugs, periphyton, and fish. Read on to discover why Z-grass is so important in the Fall River and what progress the research team accomplished in 2013.
Zannichellia palustris is an important native aquatic species that has been in decline in the Fall River for many years likely due to over sedimentation (Spencer and Ksander 2002). The decline of Z-grass is one of particular importance because it has a significant positive effect on species diversity and species interactions, providing fish food via invertebrate habitat and refuge from predation, particularly when it is present throughout the water column. Therefore, by encouraging the growth of native aquatic species such as Z-grass, the ecosystem may have a better chance of out-competing aquatic invasive species. Due to the positive role of Z-grass in the food chain of the Fall River, the re-vegetation of Z-grass in the river is a conservation priority for the Fall River Conservancy.
1. What are the most successful and cost effective methods of Z. palustris re-vegetation in the Fall River?
2. Following the establishment of Z. palustris, are there positive effects in fish habitat as measured by invertebrate and periphyton activity?
In-stream restoration of aquatic vegetation has not been attempted experimentally, thus preliminary experimentation was needed to establish methodologies for plant propagation. The evaluation of different seeding and planting techniques began with technical trials in the spring and summer of 2013 at Chico State University lab facilities. About 25,000 seeds were collected and were used for experimentation. Researchers experimented with germination techniques and examined the effects of temperatures, sediment depth and disturbance, anchoring, and seeding to determine the most efficacious methods for plant establishment.
The following planting treatments will be used in the winter of 2013/2014:
- Control (no treatment)
- Sediment disturbance
- Direct seeding without anchoring to the river bottom
- Planting young plants without anchoring to the river bottom
- Direct seeding with anchoring via a biodegradable fabric anchored with stakes, and
- Planting young plants with anchored fabric.
Each of the six treatments will be replicated three times at different locations along the river between the headwaters of the Fall River and the Spring Creek Bridge. At each site, each treatment will be replicated five times for a total of 90 plots. Each experimental plot will be 1.5 m2 with 30 plants or seeds per site. Planting and seeding densities will be adjusted in the field.
2014 Research Team Follow-ups
Monthly sampling of all plots will include the following measurements: stem/plant frequency, mortality, and percent cover. Plots will be sampled with a sinkable plot, photographed with an underwater camera and the images evaluated in the lab. Preliminary work indicates that this is an effective sampling method. At quarterly intervals, leaf samples will be collected and quantified for periphyton colonization and composition. Invertebrate composition in the plots will also be sampled quarterly with nets without damage to the plants. One year after planting, five plants from each plot will be harvested, dried and measured for above and below ground biomass. Data will be analyzed with an Analysis of Variance for differences among treatments and ordination methods will be used to assess environmental parameters associated with planting.
Check back in 2014 for findings and updates from the Chico State Z-Grass research team.