CHI Archive

Researching the effects of climate change on ecosystems to sustain California’s biodiversity.

Securing the future of our natural systems

The California Heartbeat Initiative (CHI) engages the diverse population of the Golden State to create an ecologically resilient future. The project applies research and monitoring, data analysis and communication, and training and mentoring to address climate warming, ecological change, and habitat loss.

The UC Natural Reserve System is the backbone of all CHI endeavors. With its diverse network of protected wildlands, the NRS is an ideal platform for research that seeks to secure a resilient future for humans and the natural world. CHI research benefits from longstanding NRS partnerships with major land management agencies, environmental organizations, and other universities. Read more

California Heartbeat Initiative 20191015

Consequences of fire on California ecosystems
Drones and pressure bombs to study vegetation water use
Can drones be used to measure water stress in plants?
Parrot Sequoia & Pix4D – Climate Innovation – Long Version


The California Heartbeat Initiative is revolutionizing how to monitor the water available to an ecosystem. Plants must have water in their tissues to convert sunlight into food, produce oxygen, and stay upright rather than droop. The gold standard for evaluating a plant’s water status is to sample its leaves both before dawn and in midday heat. Unfortunately, this method is laborious and time consuming. It is difficult to measure more than a few plants at a time, much less an entire landscape.


From soil to outer space

CHI is working to automate this process. The project conducts drone flights to gauge water content in the atmosphere, in plants, and in soils across the landscape. Additional measurements of surface water and groundwater resources are also being taken. The project correlates trusted local monitoring methods with remotely sensed data from drones and satellites. The project will integrate all of these data to establish new methods to monitor hydrologic status at landscape scale. All of these environmental measurements can be accessed via an online portal that delivers the information easily for analysis.

CHI Equipment

A compact sensor package

CHI has combined the detection of environmental conditions into one compact instrument bundle. Mounted atop a tripod that can flex with the wind, the CHI sensor package bristles with a suite of research grade sensors capable of monitoring a wide range of environmental characteristics.

Crowning the tripod is a miniaturized climate station. Able to measure the usual weather characteristics, from humidity to rainfall and temperature to wind speed, it can also measure the availability of light wavelengths capable of powering plants, thanks to a photosynthetically available radiation (PAR) sensor. A radio listens for electrical bursts of a specific frequency to count lightning strikes. And a pair of leaf-shaped sensors hanging off the side measures the degree of wetness nearby leaves are experiencing.

Cables from the tripod power instruments on a nearby tree and beneath the ground. The instrument lashed to the tree is a sap flow meter. It measures how fast fluid is moving from the tree’s roots toward its leaves. Leaves need water to make sugar through photosynthesis, then transpire that water into the atmosphere. The sap flow meter pulses heat into the fluid within a tree’s vessels, and measures how long it takes for the warmed sap to rise to a nearby heat sensor.

Soil and tree canopy connections

Beneath the surface, the cables fuel instruments that measure soil moisture at range of different depths. These readings give a sense of how much water is available for plant roots to absorb.

A data logger clipped to a leg of the tripod stores the information gleaned from all of the instruments. Finally, an adjacent transmitter sends the data wirelessly to reserve headquarters. From there, it is uploaded to the internet and available to researchers in real time.

The solar panel that powers all of the instruments allows the sensor package can be deployed far from the grid.

Jim Norris

View from the sky

CHI deploys unmanned aerial vehicles, or drones, to collect data across a large area. Multi-spectral and 360° cameras mounted on the drones collect information on topography and surface water distribution as well as rates of photosynthesis.  

The resulting data can be used to reconstruct 3D models of entire trees, and track the fate of environmental water.



Dendra is a portal for data collected by permanent environmental monitoring efforts. The project stores real-time information from instrument arrays such as environmental sensor packages and climate monitoring stations. Datasets can then be retrieved, managed, curated, and downloaded via Dendra’s user-friendly interface.

Geospatial Portal

The Geospatial Portal serves up geographic information system data about NRSs. Data types include photos; drone images; maps of soils, vegetation, and hydrology; museum specimens; and other large datasets.

Research sites

CHI research is being conducted at across multiple UC NRS reserves as well as other protected lands across California. Ten study sites were selected to represent the climate gradient across California and a variety of ecosystems, while making the most of existing instrumentation and the engagement of faculty. The study sites consisted of nine UC NRS reserves and one UC Research and Extension Center.

Post-fire sites

Fire scorched nine NRS reserves during the summer of 2020. Eight reserves burned in wildfires resulting from lightning strikes. In addition, the fire at Landels-Hill Big Creek Reserve was set by an arsonist, while the fire at Oasis de los Osos (a satellite reserve of the NRS’s James San Jacinto Mountains Reserve) was sparked by a car crash. The CHI research protocol, including drone flights and ground surveys, is now being conducted at all burned reserves to characterize the way native ecosystems recover from fire. Fire is becoming more frequent in California due to a warming and drying climate, making the understanding of fire recovery critical for informing conservation and land management practices.

More site information


The California Heartbeat Initiative (CHI) is part of the UC NRS, using the 41 reserve network across the state as the backbone to apply research and monitoring, data analysis and communication, and training and mentoring to the pressing environmental issues of climate warming, ecological change, and habitat loss. Every aspect of CHI provides environmental STEM experiences to college students and young professionals from groups underrepresented in the environmental sciences.

The UC Natural Reserve System, the largest university run system of reserves in the world, is the backbone for these efforts. Its 41 reserves across California encompass more than 756,000 acres, 50 miles of coastline, and over 2000 native plant and animal species.

The UC NRS is a library of ecosystems throughout California. Most of the state’s major habitat types are represented, from coastal tidepools to inland deserts, and lush wetlands to redwood forests. No other network of field sites can match its size, scope, and ecological diversity. The NRS offers outdoor laboratories to field scientists, classrooms without walls for students, and nature’s inspiration to all.

CHI’s first focus topic is freshwater and it’s distribution within the ecosystem. By combining environmental sensors on the ground with multispectral drone and satellite imagery researchers have been able to get a landscape scale glimpse into the how our ecosystems use and store water through the year. CHI is currently a partnership among the UC Natural Reserve System, UC Research and Extension Centers, California State Universities, California State Parks, National Parks and private field stations. Our team members (link are based at the UC Office of the President, UC Berkeley, and UC Santa Cruz.


The California Heartbeat Initiative is funded by the Gordon and Betty Moore Foundation, which fosters path-breaking scientific discovery, environmental conservation, patient care improvements and preservation of the special character of the Bay Area. Visit or follow @MooreFound.