This dissertation strived to understand the social-ecological systems (SES) dynamics in thernBorana rangelands, how these transformations derived pastoral system vulnerability and howrnpastoralists are responding to the changes. In relating pastoral system vulnerability with therncrisis in environmental governance, the paper strived to unpack the Borana rangelandrngovernance systems including customary institutions, evolving pastoral development policies,rnand network form of rangeland governance. The study employed a mix of primary data collectionrnmethods such as focused group discussions (FGDs), key informant interviews, observation andrnhousehold survey of 186 respondents randomly selected from six purposively selected kebeles inrnYabello district. To examine network governance structures, social network analysis(with a totalrnof 53 actors) was conducted. To analyze the collected data, various tools such as descriptivernstatistics, index and econometric (logit) model were employed. The Borana pastoral SES hasrnundergone negative transformations due to interrelated deriving forces such as climate, socioeconomic, policy, and geopolitical dynamics. As a consequence, the resilience of the SES of thernpastoral system has considerably been deteriorated. Indigenous rangeland governancerninstitutions are weakening due to reinforcing internal and external factors which, in turn,rnendangered the sustainable governance of the human-rangeland ecology interactions. Althoughrnthey are less likely to abandon pastoralism, most of the Borana pastoral households were found tornhave already embraced diverse non-pastoral activities (some of which have negative implicationsrnfor the resilience of the pastoral system) to sustain their life in the face of internal and externalrnpressures. The social network analysis revealed that the current rangeland governance structuresrnhave limited capacity to develop a collaborative process and sufficiently respond to complexrnrangeland governance challenges. Based on the findings, it is recommended that in the first placernthe mono-centric and top-down governance approaches that decoupled human subsystem fromrnecological subsystem should be shifted towards holistic approaches and collaborative process thatrnencourage the networks of actors enabling the use of scattered resources and capacities acrossrnscales, sectors, and domains of the governance system. In line with this, as customaryrninstitutions are deep-rooted in the indigenous knowledge and value systems, revitalizing therncustomary institutions is suggested to establish multi-governance structures that can enhancernSES resilience.