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Erasme Uyizeye, Ph.D., is a 2020 graduate of the Ph.D. Program in Environmental Studies at Antioch University, New England

Dissertation Committee:

  • Beth A. Kaplin, Ph.D., Committee Chair
  • Lisbeth Willey, Ph.D., Committee Member
  • Viola Clausnitzer, Ph.D., Committee Member

Keywords

Odonates, dragonflies, biological indicators, biotic index, freshwater ecosystems, monitoring, integrated management, adaptive management, agriculture, mining, Africa, Rwanda

Document Type

Dissertation

Publication Date

2020

Abstract

Worldwide, the decline of biodiversity in freshwater ecosystems is occurring at an alarming rate, due to anthropogenic threats, which directly impact humans in a variety of ways. Freshwater ecosystems occupy an integral part of political, socio-economic and ecological spheres. Integrated Watershed Management (IWM) and Adaptive Management (AM) conceptual frameworks provide an underpinning holistic platform from which to evaluate the performance of policies and actions on the ground in relation to freshwater ecosystem management. I investigate the extent to which environmental policies and practices embrace IWM and AM frameworks in Rwanda. Furthermore, this dissertation develops an odonate-based ecological monitoring tool, referred to as Dragonfly Biotic Index (DBI). The development of this tool involved surveying adult odonates, water physical-chemical variables, habitat characteristics and weather conditions across the six ecological zones of Rwanda. An average of 16 sites per each ecological zone were surveyed in a short rainy season and revisited in a short dry season. This countrywide survey added 25 new odonate species to the national check list, which increased it to 114 species. The abundance of odonates was significantly different between ecological zones and between seasons. The DBI developed here consists of three sub-indices: distribution-based score, sensitivity-based score and threat-based score as per IUCN Red List categories. To validate DBI, I examined its effectiveness in reflecting habitat integrity. This included using DBI to assess the relationship of land uses (agriculture and mining) and environmental, and physical- chemical variables of freshwater ecosystems. DBI values were significantly lower in agricultural and mining sites than their control sites. Also, significant changes in some environmental variables were associated with the two land uses. These included the degradation of riparian vegetation as associated with both agriculture and mining. While agriculture was significantly associated with higher conductivity, mining exhibited a significant relationship with higher water turbidity and higher sandy substrates than their control sites. In conclusion, not only will DBI enable deeper investigation of the extent to which land uses affect freshwater ecosystems, but also will be instrumental in prioritization for habitats that need crucial conservation. Additionally, this monitoring tool is meant to make data on ecosystem status readily available to facilitate analysis of ecological responses to socio-economic, political and pragmatic interventions. Thus, these data can be used to inform all spheres involved: ecological, political and socio-economic. The use of odonates, which are charismatic insects, will potentially engage and promote citizen-based monitoring. This will ultimately instill pro-environmental attitudes within local communities and set the stage for collaboration between stakeholders.

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