Wesley R. Brooks

Knowledge gain and behavioral change in citizen-science programs.

Citizen-science programs are often touted as useful for advancing conservation literacy, scientific knowledge, and increasing scientific-reasoning skills among the public. Guidelines for collaboration among scientists and the public are lacking and the extent to which these citizen-science initiatives change behavior is relatively unstudied. Over two years, we studied 82 participants in a three-day program that included education about non-native invasive plants and collection of data on the occurrence of those plants. Volunteers were given background knowledge about invasive plant ecology and trained on a specific protocol for collecting invasive plant data. They then collected data and later gathered as a group to analyze data and discuss responsible environmental behavior with respect to invasive plants. We tested whether participants without experience in plant identification and with little knowledge of invasive plants increased their knowledge of invasive species ecology, participation increased knowledge of scientific methods, and participation affected behavior. Knowledge of invasive plants increased on average 24%, but participation was insufficient to increase understanding of how scientific research is conducted. Participants reported increased ability to recognize invasive plants and increased awareness of effects of invasive plants on the environment, but this translated into little change in behavior regarding invasive plants. Potential conflicts between scientific goals, educational goals, and the motivation of participants must be considered during program design.

Evaluating the performance of volunteers in mapping invasive plants in public conservation lands.

Citizen science programs are touted as useful tools for engaging the public in science and for collecting important data for scientists and resource managers. To accomplish the latter, it must be shown that data collected by volunteers is sufficiently accurate and reliable. We engaged 119 volunteers over three years to map and estimate abundance of invasive plants in New York and New Jersey parklands. We tested their accuracy via collected pressed samples and by subsampling their transect points. We also compared the performances of volunteers and botanical experts. Our results support the notion that volunteer participation can enhance the data generated by scientists alone. We found that the quality of data collected might be affected by the environment in which the data are collected. We suggest that giving consideration to how people learn can not only help to achieve educational goals but can also help to produce more data to be used in scientific study.

Enhanced interspecific territoriality and the invasion success of the spotted tilapia (Tilapia mariae) in South Florida

South Florida’s freshwaters are amongst the most invaded in the world with 34 naturalized fish species. How these non-natives affect the local native fish populations, however, is largely unknown. Native sunfish of the genus Lepomis are important as predators in structuring fish and invertebrate assemblages in the swamps and seasonal wet prairies of the Big Cypress Swamp and Florida Everglades. The spotted tilapia, Tilapia mariae, is a successful West African invader that exhibits territorial and spawning behavior that closely matches that of native Lepomis sunfishes. We tested the hypothesis that Lepomis sunfishes and T. mariae would compete when space was limiting. Additionally, we predicted that T. mariae, because of their aggressiveness, would be more successful in acquiring space. We collected juveniles of both groups from Big Cypress National Preserve, Everglades National Park, and the South Florida Water Management District canal system for laboratory trials in which likely competitive interactions were staged and observed. T. mariae were bolder and more aggressive than Lepomis sunfishes. T. mariae residents resisted all intruders whereas 30% of Lepomis sunfish residents were ejected. We surmise that these enhanced behaviors of T. mariae are an important component of their success in South Florida. The continued spread of T. mariae populations throughout South Florida into natural habitats suggests an increasing potential to affect the quality of spawning habitat available for Lepomis sunfishes and warrants a renewed focus on T. mariae as a non-native species of special concern.

Balancing broad ideas with context: an evaluation of student accuracy in describing ecosystem processes after a system-level intervention

Promoting student understanding of ecosystem processes is critical to biological education. Yet, teaching complex life systems can be difficult because systems are dynamic and often behave in a non-linear manner. In this paper, we discuss assessment results from a middle school classroom intervention in which a conceptual representation framework is embedded in a suite of technology tools. We use both hand-drawn models and open-ended written responses to evaluate student understanding. While we speculated that our intervention would help students use ecosystem mechanisms to describe broader processes, we found instead that students tended to express constructs in isolation (as opposed to a unified picture of ecosystem processes). In addition, students provided greater elaboration of ideas mostly when specifically prompted. Specific prompts also tended to produce more accurate representations of the ecosystem processes our curriculum covered. Our findings have allowed us to refine our intervention to better translate these critical concepts, and how they are interrelated, to young learners. As such, these findings have important implications for encouraging broader ecosystem thinking in K-12 classrooms.

Tropical paradox: a multi-scale analysis of the invasion paradox within Miami Rock Ridge tropical hardwood hammocks

The invasion paradox describes the scale dependence of native-exotic richness relationships (NERRs), where NERRs are negative at neighborhood scales and positive at landscape scales. However, a lack of tropical surveys and past failures to isolate potential confounding variables contribute to significant gaps in our understanding of the processes producing these patterns. We surveyed the vascular flora of 13 tropical hardwood hammocks for community characteristics (e.g., native and exotic species richness, vegetative cover) with a hierarchical sampling design. Using model selection, we determined which variables best predicted patterns of exotic species richness at each spatial scale of consideration. We found that native and exotic species richness were positively correlated at neighborhood scales, but negatively correlated at landscape scales. The latter result stands in stark opposition to the patterns published in the literature thus far. We found that natural disturbance history (as approximated by vegetative cover) was positively correlated with exotic species richness at intermediate and landscape scales only. Overall, hammock identity was the most important factor driving exotic species richness patterns at all spatial scales. Hammocks with highly-disturbed hydrologies, brought about by water management, had fewer native species and more exotic species than hammocks with more natural hydrological conditions. Our results are among the first from examination of subtropical communities, and may support the hypothesis that tropical and subtropical communities are subject to more intense biotic interactions. However, given our unique sampling design, our results do not reject the hypothesis that environmental heterogeneity drives the relationship between native and exotic species richness patterns.