Optimizing techniques to restore forest to increase endangered species habitat and mitigate future drought: Kanakaleonui Bird Corridor

A dry grassy landscape of gently rolling hillocks and occasional trees.
Project Site on Mauna Kea, the Kanakaleonui Bird Corridor. (Photo: APigeo)

Cloud water (fog) capture is critically important for the maintenance of cloud forest ecosystems: trees intercept water droplets from the air, condensing them and leading to their deposition on the soil surface at higher rates than if plants were not there. Trees also add organic material to soils, halt erosion, help with water infiltration, and buffer soil surfaces from drying sun and wind. Thus, plants have a positive effect on ecosystem water capture, and in turn, ecosystem water retention has a positive effect on plant growth.

Such positive feedbacks help create ecosystems that are resilient to change. Unfortunately, once part of the equation is lost, the system moves into an equally resilient degraded state: if there are no plants to capture water, then there is also no moisture for seed germination, and the system becomes ‘stuck’ in a degraded state. If further dried out by a changing climate, such degraded, resilient states can become even harder to restore.

Various techniques have been developed to deal with harsh climate and soil conditions in restoration projects in other locations. In areas that receive fog inundation but lack the ability to intercept water droplets due to a lack of trees, synthetic fog capturing devices have been used to “harvest” water and deposit it onto the soil surface available for plant uptake. Various prototypes of such structures have been implemented globally.

A wired box is attached to a metal pole that is part of a wire fence in a dry grassy fields.
Soil probes that are placed 15 cm. underground to track moisture levels on each sides of the net. Six probes per cite are plugged into a Zentra ZL6 Data Logger (Brain) which records moisture daily. This should yield important data about climate of the corridor over time. (Photo: APigeo)

Our study focuses on potentially rebuilding this relationship by using fog capture systems to help to water seedlings. Kanakaleonui Bird Corridor (KBC) has a degraded Sophora chrysophylla (māmane) forest currently dominated by exotic grasses, highly eroded soils, and few native trees (Leopold and Hess 2017). While this current grassland could potentially serve as a corridor for endangered birds between Hakalau Forest NWR and Mauna Kea Forest Reserve at higher elevations, it is currently a fire risk given the abundant fuel loads created by the dry, exotic grasses. We are working with Department of Hawaiian Homelands (DHHL), Mauna Kea Watershed Alliance (MKWA), and US Fish and Wildlife (FWS), who currently help manage this corridor. We hope to better understand the benefits that capturing fog water can bring to this high elevation, low precipitaion, and high invasive grass matrix, in the hopes of ultimately regenerating a native forest.





Jonathan Price
Professor of Geography , UH Hilo


Amberly Pigao
Tropical Conservation Biology & Environmental Science, UH Hilo


Stephanie Yelenik
Research ecologist, PIERC, USGS
Cheyenne Perry
Coordinator, Mauna Kea Watershed Alliance
Joseph Kualiʻi Camara
Land Agent, Dept of Hawaiian Homelands
Kyle Rose
Assistant Professor of Forestry, New Mexico Highlands University