Portland State University. Environmental Sciences and Resources Ph. D. Program
Catherine E. de Rivera
Date of Award
Doctor of Philosophy (Ph.D.) in Environmental Sciences and Resources
Environmental Sciences and Resources
1 online resource (xiii, 221 pages)
Plant phenology, Insect pollinators -- Habitat, Environmental sciences -- Research -- Citizen participation
Environmental problems are growing at a pace and scale that traditional research methods alone can no longer tackle. Innovative research models that utilize contributory, participatory and crowdsourcing methods are rapidly emerging to fill this gap. For these participatory efforts to be effective and sustainable, however, closer attention must be paid to key components that can promote coordinated action and sustainability. Through the lens of public participation in plant-pollinator conservation, I have, with rigorous social-ecological inquiry, offered three foundational assessment areas that can provide scientific support to this nascent field: accuracy, ecological significance and scalability.
In the first study (Chapter 2), I explored a common concern about citizen science: that a lack of foundational knowledge, or familiarity with following scientific protocols could lead to inaccurate data collection. I evaluated the accuracy of plant phenology observations collected by citizen scientist volunteers following protocols designed by the USA National Phenology Network (USA-NPN). Phenology observations made by volunteers receiving several hours of formal training were compared to those collected independently by a professional ecologist. Approximately 11,000 observations were recorded by 28 volunteers over the course of one field season. Volunteers consistently identified phenophases correctly (91% overall and 70% during transitions) for the 19 species observed. Accuracy varied significantly by phenophase and species (p<0.0001). Volunteers who submitted fewer observations over the period of study did not exhibit a higher error rate than those who submitted more total observations, suggesting that volunteers with limited training and experience can provide reliable observations when following explicit, standardized protocols. Overall, these findings demonstrate the ii legitimacy of phenology observations collected by volunteers, an important finding for the increasing number of analysts relying on data collected by citizen scientists.
In Chapter 3, I explored a common concern that restoration efforts implemented by the public may not have adequate ecological value. I addressed key ecological variables to determine how small-scale patches attracted pollinators and explored which of these variables might be best to prioritize for restoration efforts suited to public initiatives. This study demonstrated that in small-scale plant restoration sites, plant diversity and resource (nectar) availability significantly affects the abundance and diversity of pollinating insects. Specifically, the treatments which contained high-resource (nectar-rich) plant species increased pollinator abundance and diversity the most. Plant diversity increased pollinator diversity and abundance only in the absence of high-resource plants. Pollination facilitation was observed in high resource treatments, but varied among species. Competition for pollinators was observed in high diversity treatments but did not affect seed set for high-resource plants in any of the treatments. Together, these results suggest that managers or landowners who are restoring patches of native plants as habitat for pollinators should prioritize including species with high nectar production, and secondarily, a diverse mix of species if space and resources allow.
In Chapter 4, I explored an emergent approach to public participation in regional community science initiatives (and networks) through an exploratory case study of the New York Phenology Project. I demonstrated that local organizations have the opportunity to utilize existing data aggregation platforms to activate regional collaborative alliances to achieve what is often challenging for large-scale contributory projects. I describe our hands-on experience of conceiving and launching a regional network and outline a model that could serve as a guide for catalyzing networks. Drawing on direct experience and interviews with network partners, I developed a description of key categories related to network node success, and a linked assessment tool that could be used to evaluate network node capacity and project outcomes. The assessment tool will be used to test preliminary findings in a more formal quantitative and qualitative exploration in future studies.
In Chapter 5, I explored an exceptional long-term, community-level phenology data set that spans New York State, USA (1802-2017), and found interesting and significant patterns of phenological change over time. The data set provides statewide phenology and temperature data that extend further back in time than any previously known data set for the region, extending to years prior to or at the beginning of recent human-caused global warming. I found that most species are flowering and leafing earlier in recent years (2009-2017) than they did in the early 19th century (1802-1861). Plants are flowering 11 days earlier and leafing 18.8 days earlier, with some species flowering up to 27 days earlier and leafing up to 31 days earlier over that time period. Most of this change was driven by warming mean spring temperatures (MST) over that time; mean spring temperatures warmed by 1.0°C statewide (2.5°C in New York City) on average between the historical and contemporary periods. Seasonality, Life Form, and the interaction between Seasonality and Life Form explained variation in phenology among species. The large number of geographically distinct sites in this dataset permitted novel investigation into differential changes in phenology between urban and rural areas (urban areas have more advanced phenology than their rural counterparts) and between insect and wind pollinated trees by seasonal category (insect pollinated trees are showing more advanced phenology than wind pollinated trees in both early and late spring). This analysis has brought the efforts of a historical network into a modern context and has illustrated how organized long-term monitoring efforts can be valuable for ecological discovery.
This combined work provides a diverse contribution to the field of public participation in monitoring and conservation efforts. While thorough and disciplined ecological theories drive the design of the research, I simultaneously strove to help meet the ongoing demand for useable, purposeful insights into how to support public efforts to restore plant-pollinator habitats, monitor key ecological dynamics such as phenology, and scale networks capable of collecting data that address issues of global change.
Battle, Kerissa, "Public Participation in Plant-Pollinator Conservation: Key Assessment Areas that Support Networked Restoration and Monitoring" (2018). Dissertations and Theses. Paper 4228.
Available for download on Tuesday, March 19, 2019