Climber reaching into snow

Black carbon and light absorbing particles on glaciers

Glaciers in the tropical Andes have been melting at an alarming rate since the 1950s.  Light absorbing particles on glacier surfaces may have been contributing to increases in melt rates.  The goal of the black carbon research is to determine the types and amounts of light absorbing particles make it into the snowpack.



Researcher preparing samples

Effects of cattle grazing on soil nitrogen dynamics in high-elevation grasslands

Tropical mountains are facing a host of environmental stressors, including warming temperatures and land-use change. How hydrologic and biogeochemical cycles respond will impact the provision of key ecosystem services and is a critical research topic with implications from local to global scales.



research team

Impacts of grazing and climate variability on high-elevation ecosystems

Tropical high altitude ecosystems are particularly vulnerable to the combined effects of land degradation and climate change. Mountain ecosystems globally have been extensively altered through deforestation, burning, and grazing of livestock.  We are testing how native grasslands respond to reduced grazing pressure and how these responses vary across an altitudinal gradient.



researcher collecting sample

Controls on nitrogen in mountainous tropical forests

The tropics are projected to experience pronounced climatic change in the century yet our understanding of how forest functions will respond is incomplete. This presents a challenge since tropical forests play crucial roles in regulating Earth's biogeochemical cycles and climate.




John All taking notes standing on a mountain

Climate change and land use in Sagarmatha National Park, Nepal

The goal of our work in the Himalayas is to document changes in high mountain ecosystems as they respond to the integrated effects of multiple stressors, including human land use decisions and climate variability and change. 




Mountain flowers

Flora of Huascaran National Park and the Cordillera Blanca

In conjunction with our ground reference data research, we have collected several thousand images of plants and are identifying them in cooperation with numerous Peruvian botanists and other experts.  We will choose the best images of the most representative species in the Cordillera and print a field guide that can be used by researchers and visitors to the park.




Researchers comparing data

Changes in the fire regimes of the Cordillera Blanca, Peru

In Huascarán National Park, Peru, grazing and anthropogenic burning have been interacting for decades with natural ignitions and climate change to reconfigure the fire regime of the vegetative communities. Local resource managers are very concerned about the impacts of anthropogenic fires in the Park because they potentially disrupt ecological processes as well as tourism.




Map showing areas of Peru explored in 2014

Differentiating climatic and anthropogenic alpine land cover change drivers over the past forty years in the Cordillera Blanca, Peru

This project examines land cover/land use changes for the past forty years in Huascaran National Park and the adjacent communal areas.  There is a wealth of satellite imagery available for the Cordillera Blanca, but it needs to be verified on the ground.  We visit multiple valleys and peaks to collect information on the surface characteristics including slope, aspect, soils, disturbances, fire evidence, grazing impacts, insect damage, vegetation species, vegetation health, and other vegetation information.  






Researcher sitting next to a lake

Water quality during rapid glacier loss

Water is an increasingly valuable and scarce resource due to global population growth, local anthropogenic activity and climate change.  Many populations that rely on threatened water sources are at high risk of their supply being reduced both in quality and quantity.  In the Ancash region of Peru, a large percentage of the population relies on water coming directly from the Cordillera Blanca mountain range, which is home to the highest density of tropical glaciers globally. 




Sample collector in forest underbrush

Monitoring arthropod diversity in high-elevation ecosystems

Arthropods are among the most diverse and abundant group of animals found in tropical forests. Arthropods that live in litter and soil provide a number of ecosystem services such as maintenance of soil structure and nutrient cycling. Despite the key ecological roles of these organisms, very little is known about arthropods communities in high elevation tropical ecosystems.