Glacier forefield environments have long acted as natural laboratories for understanding the establishment of ecological communities in newly available habitat. There is often a long lag in the initial colonization of plants in alpine ecosystems because of limited soil nutrients. However, there may be strong animal-plant facilitation mechanisms at play, where communal dung deposition by native herbivores creates nutrient hotspots and fuels more rapid plant establishment. The project will define how nutrient hotspots ameliorate extreme abiotic conditions and accelerate primary succession in high-mountain landscapes, facilitating the development of pioneer communities and upslope expansion of plants and other organisms into glacier forefields. The research will provide strong research and professional training and mentoring for students at multiple career stages at a primarily undergraduate institution. Two Master’s students, 6–12 undergraduates, a post-baccalaureate research technician, and at least one local Peruvian student will receive training through this project, equipping the next generation of climate change biologists with skills to address growing challenges in this field. Revealing unexplored processes underlying how ecological communities will keep pace with rapid climate change will enable future experimental and predictive modeling work, which can inform urgently-needed stewardship of lands newly exposed by retreating ice.<br/><br/>Animal-plant facilitation might be a more ubiquitous mechanism of primary succession than currently recognized in newly-exposed deglaciating lands worldwide. The lack of understanding of the potentially significant role of animal-mediated facilitation impairs our ability to predict how glacier forefield biodiversity, assemblages, and ecosystem function will develop under rapid climate change. The goal of this proposal is to understand the consequences of nutrient hotspots created by animals in terms of ecosystem succession. This research will help to create a new conceptual model of the earliest stages of ecosystem development in glacier forefields supported by extensive field data, and guide future predictive and experimental work. A multi-scale, field-based approach will reveal how hotspots alter glacier forefield community development. The specific aims are to: 1) define patch-level impacts of hotspots on soil nutrients, microbial biomass, and plant characteristics in glacier forefields; 2) determine landscape-level hotspot effects on plant and microbial community assembly across a 130-year chronosequence of glacier retreat; and 3) define patterns of animal activity and nutrient deposition at hotspots and non-hotspot locations.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.