The Kaua‘i Watershed Alliance
Management Programs
Home
About the KWA
The Watershed
Projects
Management Programs
Volunteer Information
Maps and Documents
Photo Gallery
Conservation Links
Contacts
Monitoring objectives were based on a recent review of monitoring programs throughout the state. The four main objectives are to measure the:
Objective 1: Effectiveness of ungulate management actions.
Objective 2: Effectiveness of weed management actions.
Objective 3: Long-term changes in vegetation cover throughout core management areas.
Objective 4: Long-term changes in stream turbidity throughout core management areas.
Ungulate monitoring will directly evaluate the performance of ungulate management actions while providing short-term feedback to the KWA partners and managers to inform adaptive management. A network of monitoring transects will allow teams to assess the effectiveness of management and the health of the watershed. Ungulates, weeds, and ecosystem health measures will be gathered at regular intervals.
Ungulate activity monitoring will comprise the majority of the KWA’s monitoring efforts. Methods proposed are based on those used by the East Maui Watershed Partnership. Ungulate activity monitoring will occur along belt transects. (See Map)These transects will be placed along existing Hawai‘i Forest Bird (HFB) Survey transects, or along stream corridors and hunter trails reducing the need to install new transects.
Managers will record, at a minimum, the presence or absence of pig sign within each plot and report the percent of plots with sign in each transect to give an overall activity percentage for each year. This simple method eliminates subjectivity and produces consistent and repeatable results independent of staff changes. Transects will be monitored annually during the season with the highest activity levels. Hawai‘i Forest Bird Survey transects are located throughout the watershed and provide good spatial coverage in all native ecosystems and priority management units (See Map). In addition to the transect data, managers will map and report ungulate sign sighted during routine management actions.
Aerial surveys will be the primary means of measuring the effectiveness of weed management actions. After initial baseline aerial surveys are complete, additional aerial surveys along randomly selected transects planned at 100 m apart, should continue on 5 to 10-year intervals, starting with the central Alaka‘i in 2010. Additional aerial surveys will be scheduled when needed to gauge progress on specific weed management activities. Other weed distribution data, collected from field personnel during ground-based operations will be compiled in the GIS.
Detecting changes in native ecosystems at large spatial and temporal scales is difficult due to their inherent variability and slow rate of change. However, focusing on specific parameters such as vegetation cover over long periods of time should detect basic trends in ecosystem integrity.
Monitoring changes in vegetation cover will rely on 16-meter diameter permanent circular plots placed near existing transects and trails throughout priority management areas. Managers will record absolute percent cover for native and non-native vegetation species in 6 classes: tree, shrub, fern, grass & sedge, vine, and bryophytes, as well as percent ground disturbance and the presence or absence of seedlings. Sampling in each plot should occur every 5 - 10 years, and the monitoring program should take place concurrent with ungulate monitoring to save on cost.
In addition to the vegetation cover plots, high-resolution aerial imagery can detect changes in the canopy cover over longer time periods. While currently available imagery is only capable of identifying obvious vegetative contrasts (e.g., forest vs. grassland vs. bare ground), future advances in imagery and analysis techniques should identify native vs. nonnative vegetation.
Recent advances in remote sensing technology have lead to cost effective solutions that provide very high resolution aerial and satellite based imagery useful for the purposes of vegetation mapping. To date, much of the vegetation mapping and monitoring programs that have shown success in the US have come from either manual interpretation of aerial photos or image classification of moderate resolution satellite images.
With the recent introduction of very high resolution digital imagery a new chance to map vegetation at a detailed level using objective image analysis techniques has become possible. Some projects in the continental United States and here in Hawai‘i have already had some success mapping with high resolution satellite based sensors, however, challenges related to cloud cover and topography have made it very difficult to obtain the necessary data for portions of the state.
To solve this problem USGS-BRD in cooperation with TNC is developing a portable inexpensive very high resolution aerial imaging system that will be able to collect the necessary data while solving for the problems described above. The system will also have the added benefit of being able to collect imagery down to 4cm resolution if necessary, with a tertiary product of a canopy DEM that will yield canopy height information. Another product that will be tested for its applicability in mapping will be a data product produced by the Carnegie Institute. They are also putting together an aerial sensor that has the added feature of LiDAR in conjunction with Hyperspectral imagery. This system is due to come online in January of 2007.
Successful large-scale ungulate and weed management will lead to improvements in vegetation cover and declines in ground disturbance, and should result in decreased stream turbidity. Since stream turbidity is an indication of excessive over-land flow or runoff, a reduction in turbidity can be equated with improved infiltration and aquifer recharge.
Currently, no watershed-scale system to assess stream turbidity exists on Kaua‘i; however plans to deploy an array of environmental sensors, transmitters, and repeaters, including stream turbidity sensors, are underway. The monitoring program is funded through a National Science Foundation (NSF) program called EPSCOR, awarded to the University of Hawai‘i’s Center for Conservation and Research Training (CCRT). The program seeks to provide useable information to better understand and manage watershed conditions and functions.
Currently, the development and refinement of monitoring techniques is occurring in the Halele‘a District on the north shore of Kaua‘i. However, the potential exists to expand the system of sensors and repeaters to the Alaka‘i and other core management areas. The KWA should encourage and support CCRT’s efforts to deploy the system in core areas of the upper-watershed, where most of the direct threat abatement actions will occur.