The post provided by Kelly Steinberg
This post refers to the article Flood regime alters the abiotic correlates of riparian vegetation by Steinberg et al. published in Applied Vegetation Science (https://doi.org/10.1111/avsc.12572).
Running through the state of New Mexico in the southwestern United States, the Rio Grande and its associated riparian forest serve as both research site and classroom. The third week of every month finds students, ages 5 through 18, scrambling off school buses and over well-worn paths to their favorite logs on the forest floor, where they gather with their clipboards and equipment to receive instructions. As students disperse to complete their assigned tasks, the forest is filled with their chatter, the crunching of leaves, and the beeping of water monitors. Over these noises, you might also hear the drumming of a woodpecker or the call of a sandhill crane and see an enthusiastic finger pointing in its direction. You can feel the excitement of a field day with the Bosque Ecosystem Monitoring Program (BEMP, www.bemp.org).
The Rio Grande Bosque (bosque is Spanish for forest) is a cottonwood-willow forest contained between the river and levees that stretches 400 km through the state of New Mexico. The bosque serves many functions: it is a wildlife and migration corridor, a flooding buffer zone in urban and agricultural areas, a filter for flood water, and a much-loved classroom to thousands of students each year throughout the state. Established in 1997, BEMP trains students on data collection protocols to assist in long-term monitoring efforts. Each month students visit one of 34 sites with a teacher and a staff member or undergraduate intern to collect data on groundwater depth, precipitation, and vegetation. Through this community science effort, BEMP has collected millions of data points over two and a half decades, sharing trends, insights, and student-collected data with land managers, scientists, and the public.
In this paper, we used the student-collected groundwater water and precipitation data along with plant cover data to investigate how flooding affects the sensitivity of the riparian plant communities to climate change. While all the study sites have a history of spring flooding, river regulation and incised banks mean that much of the riparian zone floods only rarely. By removing spring flooding events, we hypothesized that plant communities might be responding to climate and groundwater availability differently.
We found that among sites that still flood, plant diversity was correlated with depth to groundwater, a well-known driver of riparian plant communities. However, at non-flooding sites, plant diversity was not significantly correlated to depth to groundwater, but rather to inter-annual groundwater variability. We also found that the relationship of native plant cover to groundwater depth and variability, temperature, and precipitation can vary greatly in both strength and direction between flooding and non-flooding sites. While groundwater depth has been well studied in riparian ecosystems, our results indicate that seasonal variability in groundwater depth may play an important role, particularly in plant communities that no longer flood. These findings also suggest that flooding and non-flooding riparian plant communities will respond to climate change very differently and may require different strategies by land managers looking to maintain diversity and native species.
As a community science program, BEMP seeks to empower students by including them in the data collection that informs management of the Rio Grande Bosque. After working with thousands of students to collect the data used in this paper, the authors are proud to include these future researchers, land managers, and decision makers in the work of better understanding and managing this ecosystem.
Brief personal summary: Kelly Steinberg is a science educator and ecologist, formerly with the Bosque Ecosystem Monitoring Program, and currently an Education Program Leader at the Asombro Institute for Science Education (Las Cruces, NM, USA). Her work centers around translating current scientific research into terms that young students can understand and engage with.