Plant Communities and Species Mapping Novel Remote Sensing Techniques
Knowledge of baseline conditions of natural resources is a vital, though often lacking, component of effective conservation and stewardship. Nomad has evaluated the use of aerial imagery as a tool to fill this knowledge gap.
Rare Plant Mapping Using High-Resolution Aerial Imagery
Funded by the Santa Clara Valley Habitat Agency and a Local Assistance Grant from the California Department of Fish and Wildlife, Nomad Ecology provided baseline data for the distribution and abundance of smooth lessingia (Lessingia micradenia var. glabrata) within the Santa Clara Valley Habitat Plan Habitat Conservation Plan/Natural Community Conservation Plan area. This project was intended to inform conservation strategy, monitoring, and adaptive management implementation of smooth lessingia. The impetus for this project is based on a successful remote sensing methodology Nomad implemented for smooth lessingia and rock outcrop habitat on a smaller scale at the Calero Conservation Easement located east of Morgan Hill, in the southern portion of the plan area.
In some cases, rare plant species like smooth lessingia grow in such high abundance and density that populations or colonies of these plants have a different hue or texture on the landscape that is visible from a considerable distance. Smooth lessingia, which has a reddish-brown hue, also blooms late in the summer which accentuates this contrast from the dry annual grasslands it grows in. This characteristic of smooth lessingia compared to the habitat it occupies allows for sophisticated remote sensing techniques to be employed, using aerial imagery, to map new occurrences in areas that are on inaccessible lands or in locations where landscape-scale metapopulations are more difficult to map from ground-level. Monitoring of existing populations using remote sensing techniques such as this, or with drones, is also replicable to help ensure established populations are persisting and continue to meet the Plan expectations for population size, buffers from negative influences, and to assess if population expansion has occurred. After preliminary data collection, remote sensing model creation, ground-truthing, and model adjustment, smooth lessingia was found to occupy approximately 2,660 acres within the entire study area (10,491 acres) and comprised 72 populations.
Using Drone Imagery to Map Tree And Shrub Dieoff
Infestation and spread of pathogens on native tree and shrub species can happen rapidly. Acquiring a baseline of existing conditions extremely important to track pathogen spread and plant mortality into the future. These rapid changes are difficult to capture on the ground. Using drones to capture small-scale temporal changes in vegetative health and mortality via high-resolution aerial imagery capture can assist with ecological evaluations and increase the efficiency of mapping the spatial distribution of affected plant species.
On other projects, Nomad has utilized high-resolution aerial imagery in combination with remote sensing techniques to map invasive weed species and specific rare plant species. This effort, funded by a Science and Research Grant form the East Contra Costa County Habitat Conservancy, used drone flights and spatial analysis of drone imagery to determine species and acres affected by a possible soil pathogen on Mount Diablo State Park and lands owned by Save Mount Diablo to help inform management and stewardship decisions.
A drone video with an accompanying synchronized drone flight path map of the affected area can be viewed here. Video captured by Nomad Drone Pilot Heath Bartosh (License # 4365149).