Monitoring Strangers in Paradise:
Using Remote Sensing and GIS
to Monitor Miconia and Other Plant Species
in the East Maui Watershed
The Nature Conservancy Ecosystem Research Program
"Monitoring and Managing Alien Species in the Windward East Maui Watershed"
Agreement No. 65-9521-8-326
Principal Investigators:
Dr. Jonathan C. Gradie, TerraSystems, Inc., Honolulu, Hawaii
Dr. Robyn L. Myers, Natural Resources Conservation Service, Davis, California
Table of Contents to this Page (all other links take you off this page)
DRAFT final report (content last updated November 2000):
Under a grant from The Nature Conservancy Ecosystem Research Program, Principal Investigators Dr. Jonathan C. Gradie, TerraSystems, Inc., Honolulu, Hawaii, and Dr. Robyn L. Myers, Natural Resources Conservation Service, Davis, California, are conducting a study to use GIS and remote sensing to locate and map stands of Miconia and other alien species for eradication and long term monitoring.
Finding Miconia so it can be eradicated
In Hawaii,researchers and resource managers on the island of Maui have joined together as the Maui Invasive Species Committee (MISC) to manage invasive species. They have targeted Miconia calvescens (miconia) as one of several (if not the worst) priority invasive weeds that need to be controlled on Maui, and where possible eradicated. This requires knowing where the invasive plants are, so they can be targeted for removal, as well as being able to get ground crews to ther locations on the ground. Once trees have been removed, monitoring is required to detect re-growth and new infestations. The crews need assistance in finding new plants, and finding their way on the ground through dense forest to the miconia locations of stands for removal and monitoring. It is hoped the results of this research will provide both resource managers and on-the-ground crews with information they need in this fight.
Using Multi-spectral Imagery to find specific species
Hawaiian vegetation is generally classified by plant communities, which are groups of plants that commonly grow together. Except for a few species which have a unique look on aerial photos, it is hard for all but the most experienced to pick out specific plant species of native or alien plants in aerial photography. Miconia is one of many plants that do not have a unique look, and often grows closely with other trees and plants, making it difficult to identify in standard aerial photography. The goal of this project was to use the spectral signatures of common native and alien plants to help identify them in aircraft based multi-spectral remote sensing imagery.
The advantage of multri-spectral imagery is that it detects properties of the plants that are not visible to eye in standard or even infrared photography. Because plant species generally have specific physical properties, they also generally have a unique spectral signature. In theory, differences in these signatures can be used to identify a particular plant species in multi-spectral remote sensing imagery. The challenge is to identify a standardized spectral signature for each plant, and then use that unique signature to identify other plants with the same signature, among many others, in the remote sensing image. In theory, this process should identify plants with a high probability of being the plant of interest.
Hypothesis:
Due to the unique physiology of different plant species, native, Hawaiian and alien plant species (such as Miconia calvscens), should have unique spectral properties that can be separated from the spectral signatures of other surrounding plants.
If this is true, then these spectral signatures may be used to help identify known (ground verified and located by GPS ) stands of individual species, in multi-spectral imagery.
Once the spectral signature is calibrated to identify known stands, then the spectral signature could be used to identify other stands (not ground verified with GPS) of the same species, therefore predicting their location.
The approach includes:
- Collecting GPS Ground Control Data of known location of common plants
- Collecting Ground Spectral Signatures of specific native, alien and Hawaiian species
- Flying low altitude (less than 4 meter) multispectral aerial data using TerraSystems DMSV instrument
- GIS data integration after individual data processing and analysis
- Production of maps, graphic illustrations, and detailed report
- Delivery of data and results to Maui resource managers
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Why East Maui?
Research has Shown:
- Habitat destruction is the most important factor in species loss.
- Native plants and animals are vulnerable to habitat destruction and displacement by the invasion of alien species.
Introduction of Alien Species
- Some species, like banana or sugar cane, were introduced by the Polynesians for cultivation.
- The Europeans introduced others both intentionally and accidentally, often with unexpected results on native species.
- For example, European boar mixed with the Polynesian pigs to create an alien that destroys native forest, both by their digging and by spreading alien plants into areas disturbed by pigs.
Wanted: Miconia Calvescens
- This species took over the island of Tahiti in the last 40 years, and is invading Hawai‘i.
- It is one of Hawai‘i’s “most wanted” alien species invaders. (Or one of the
"least wanted")
- Miconia work on Maui is coordinated with the Tri-Isle RC&D, Maui Invasive Species Committee, and the East Maui Watershed Partnership
click for larger map
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This project was initiated in August 1997, when we received word that our project proposal was accepted for funding. Although funding was not received until January 1998, work actually began when we submitted our Pre-proposal in Fall 1996, and continued in 1997. While awaiting funds, an inital
Pilot Project with Maui County Board of Water Supply was undertaken to
test field and aerial data collection methods, and explore preliminary
result. Copies of this report will be available below.
More extensive field and aerial data collection began in January 1998. Although originally expected to take 24 months, unusual weather in Hawaii the last several years has prevented completing the collection of the aerial multi-spectral data. The goal of delivering a method for locating and mapping vegetation of species of special concern (such as miconia) to the resource managers on Maui remains our top priority.
Research Goals and Deliverables:
- To develop new watershed analysis methods and techniques based upon airborne and ground-based spectral sensing techniques, GPS verification of sites and GIS methodologies for watershed assessment and management. [Delivered as Report available in print, CD and online]
- To develop a database of the spectral signatures of individual species of native, Polynesian and lien plant specks using a high-spectral resolution field spectrometer to measure known plant species. [Delivered as Spectral Library, available for download or on CD by request]
- To use the spectral signature library to identify spectral contrasts among various plant species and to develop a set of optimum spectral band centers and widths for airborne and space-based spectral mapping of these species. [Delivered in the Spectral Contrast Analysis report, available online or on CD by request]
- To verify identification of native and alien plant species in aerial photography and multi-spectral imagery with GPS ground-based verification and Digital Orthoquadrangles. [Delivered as GPS and DOQ data layers of the project baseline GIS dataset, and used for processing and analyzing other data]
- To identify known (GPS verified) stands of species of special concern, using their spectral signature, in multi-spectral imagery, and if possible, predict new (not GPS verified) stands of species of special concern. [Analysis is underway, and will be delivered in report and image map form in print, online and by CD on request.]
- To coordinate efforts with the Nature Conservancy, the Hawaii Natural Heritage Program, East Maui Watershed Partnership, Maui Invasive Species Committee and other concerned agencies. [Efforts to coordinate are ongoing and include regular communication our partners]
- To produce vegetation images and maps identifying areas where species of special concern occur, and have not been previously identified, for follow-up monitoring and removal (removal is not part of this project), with the primary goal of identifying Miconia. [Delivered as Report available in print, CD and online]
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GPS points and lines were taken in the field using a Trimble Pathfinder. Data were collected along the Hana Highway, the Ditch roads, roads around Hana town, and the Hana Miconia roads. Point data were taken for the specific location of individual trees, and stands of trees, large enough to be identified in aerial photos.
The handheld spectrometer data were processed to produce graphs showing
- Individual Species Reflectance
- Average Reflectance
- Normalized Reflectance
More information will be available from the GPS Ground Control Technical Report.
Spectral signatures were taken of individual plants in the watershed. using a ground spectrometer
to collect spectral signatures. A plant list of alien species of special concern, and the common native and indigenous/Polynesian plants that they occur with, was compiled by the team with the assistance of the Maui resource management team, TNCH and the HINHP.
The plants that were sampled are presented in a Field Spectral Library
that provides individual species spectral signature graphs, and download access to the raw data (as Excel *.xls files).
Preliminary Analysis:
The plots in the Spectral Library represent a comparison of the species spectra in relationship to each other, and can be used in aerial photo classifications, as well as in supervised and unsupervised classification of multi-spectral remote sensing imagery. See one example below:
A description of the DMSV data, and perhaps a small sample of what it looks like prior to orthocorrection
has been requested. Followed by a description of the orthocorrection and mosaicking process.
(In progress)
More information will be available from the Aerial Multi-Spectral Imagery Technical Report.
This section will describe the integration of all the datasets, and their analysis (so in a way includes the methods and results of the data integration process, and the analysis of that combined data set.) Here's where we "put it all together, yes?"
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This section will be a discussion of the entire project. This is where we can speculate, report results that didn't turn out the way we hoped, and present the stuff we're most proud of.
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This section will include the specific conclusions and recommendations we make to the Maui resource managers for use of the data, and management decisions that may be based on it.
Continued collaborations
We are continuing collaborations with DLNR, TNCH, and the other EMW Partners.
Data is being shared among our Federal, State, County and Other Partners
- USGS Biological Research Division
- USDA Natural Resources Conservation Service
- USDI National Park Service
- State DLNR-DOFAW
- The Nature Conservancy - HINHP
- TerraSystems, Inc.
- County of Maui
- East Maui Watershed Partnership
- Maui Invasive Species Committee (MISC)
Applying this technique to other locations and species requires:
- Useable spectral contrast between target species and background species.
- Interdisciplinary team.
- Integrated multi-scale GIS data set.
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Bibliography
This will point to a URL (html link) with a document containing our references and bibliography.
TNC Workshop Presentation, January 1998 (Jonathan)
Myers, R.L., Cory, C., Gon III, S. 1997. "Monitoring Strangers in Paradise: A
Multi-Scale Study of Native Hawaiian Rainforest." Poster session presented at
the 82nd Annual Meeting of the Ecological Society of America, held jointly with
The Nature Conservancy 11-14 August 1997.)
Phase I Report to Maui County Board of Water Supply (Word Doc)
First Annual Report to TNC - January 1998 (Word Doc)
End of FY98 Report to NRCS (Word Doc)
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Mahalo nui loa to our many partners and cooperators!
We especially wish to thank the team at TerraSystems including Pam Elman, Elbert Hwang, Ryan White, Davin Sasaki...
Thanks to Air Survey Hawaii for the use of Thunderchiken.
Thanks to Luke Flynn of ...
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Dr. Jonathan C. Gradie (email)
STI, Inc., Honolulu, Hawaii
Dr. Robyn L. Myers (email)
Natural Resources Conservation Service, Davis, California
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Site last updated: November 2003.
click for larger image of the Hana DMSV Imagery with GPS of Hana "Miconia roads"
click for larger graph