This chapter examines the causes, frequencies, and distinct and cumulative impacts of natural disturbances on both geographical and ecological space of Luquillo. It discusses the traditional scheme of quantifying effects of disturbances on a landform geomorphology and ecology by considering these factors: disturbance type, force intensity, ecosystem component, spatial extent of impact, frequency of the event, resistance of the ecosystem, and resilience of thesystem. It also covers the definition and types of mortality processes occurring over many spatial scales.

This chapter focuses on the ecological response mechanisms of the Luquillo Mountains tonatural and human-induced disturbances, such as hurricanes and land cover change. It identifies the ecosystems of the Luquillo Mountains as a perfect representation of large masses of a non-frost tropical land because of its naturally occurring features: high rainfall, hurricane disturbances, maritime climate, and insularity. It then sets out the Luquillo Long-Term Ecological Research (LTER) program as a by-product of the 20th and 21st century experimentations, and discusses its contributions to the basic understanding of the ecological make-up and biogeochemistry of the Luquillo Mountains.

This chapter examines the causal relationship between disturbance, succession, and ecological changes by considering the biotic feedback mechanisms. It also provides an outline of rippling effects of natural phenomena, agricultural clearings, river flooding, and human-induced disturbances to the Luquillo Mountains and other tropical ecosystems in the world. In this regard, this chapter describes the intellectual and societal motivations that have influenced people to further the forecast of the ecological changes over time.

This chapter describes the geologic, geographic, and ecological context of the location of Luquillo Mountains, particularly the factors affecting the response mechanisms of terrestrial and aquatic ecosystems to disturbance. It describes the existing conditions of the physical environment, chemical environment, and the biota of the Luquillo Mountains as they respond to disturbances. It then merges the decade-long research about the Mountains with the other tropical ecosystems around the globe.

This chapter describes the responses of the organisms, communities, and ecosystems to the variety of disturbances by utilizing the conceptual model discussed in Chapter 2. It also dwells on the concepts of residuals, legacies, and ecological space in the understanding of disturbances such as background treefalls, hurricanes, floods, drought, landslides, and other human-induced disturbances. Finally, it outlines the variations caused by disturbances and the interactions among these disturbances.