The Role of Citizen Scientists in Monitoring the Hemlock Woolly Adelgid (Adelges tsugae) in New Hampshire Debra Kimball (dlk@cisunix.unh.edu) M.S. Graduate, Environmental Education Department of Education University of New Hampshire

The Hemlock Ecosystem Eastern hemlock is one of the most shade tolerant and long lived tree species in the E. US. Hemlock is usually located on northern exposures, steep riparian slopes, and edges of wetlands Provides critical habitat for many plant and animal species Important in maintaining aquatic habitat, shading streams, regulating stream flow, moderating water temperatures, and shading vernal pools black throated green and blackburnian warbler, and acadian flycatcher primarily associated with hemlock forests winter shelter for deer and other mammals Stream water quality affected as hemlock stands die near riparian areas > increased N leaching

Problem The hemlock woolly adelgid (Adelges tsugae) is a small aphid-like insect that has caused extensive damage to eastern hemlock (Tsuga canadensis) stands from Georgia to Massachusetts. New Hampshire currently relies on the public to recognize HWA infestation and report it to the county forester, DES Division of Forests and Lands, or UNH Cooperative Extension

Range of HWA Infestation

Biology of A. tsugae The hemlock woolly adelgid is parthenogenetic (only females occur) Produces 2 generations/year Sistens-9 month cycle, progrediens- 4 month cycle Together they lay about 200 eggs/year Best time to see woolly ovisacs between November and June Feeds during cooler part of year inactive in summer months injects stylet into xylem ray paremchyma cells, likely injecting a toxic saliva Reddish brown nymphs can be carried to other trees via wind and animals Causes rapid desication and foliage discoloration

Hemlock Woolly Adelgid - Depletes needle of stored nutrient supplies and photosynthate

Field and Lab Measurements J. Pontius 5/04 Field and Lab Measurements Hemlock Health % New Growth Foliar Transparency % Dieback Live Crown Ratio

Hemlock Woolly Adelgid Life Cycle

Heavy infestation Note grey foliage Adelgid ovisacs on twig at base of needle

Hemlock Decline Productivity Reduced Needles desiccate and drop Dieback of limbs and entire branches Mortality typically within 4-6 years Widespread mortality expected Once HWA becomes established on hemlock, dramatic declines in new growth production are the first symptoms (Ward et al. 1992). Flushes of new growth then inversely cycle with HWA populations for several years in a density dependent feedback loop (McClure et al. 1996). As nutrient reserves are depleted, defoliation and chlorosis progresses, followed by fine twig and branch dieback. Complete mortality typically occurs within 5-6 years of the initial infestation, although some trees have been known to survive for more than 10 years (McClure 1996, Orwig 2002). Generally, the stands with the highest mortality are those that have had a population of HWA for the longest time (Mayer et al. 1998). However, exceptions to this pattern may occur, depending on environmental conditions (Mayer et al. 1998), and water stress (Onken, 1995). Most researchers now agree that all hemlock may ultimately be susceptible to HWA (Foster et al. 1999, Orwig and Foster 1998). Large canopy gaps, and in homogeneous stands, entire canopies may be opened. This is expected to reduce plant nutrient and water uptake, and increase light attenuation, soil temperatures, decomposition and nutrient cycling rates (Jenkins et al. 1999, Yorks et al. 2000). Hemlock mortality can have dramatic effects on nutrient cycling rates. Mortality may result in nutrient leaching from the soil and nutrient loading to stream water (Jenkins et al. 1999). The resulting elevated nutrient leaching could lead to site nutrient capital reduction and in turn, a reduction in forest productivity (Yorks et al. 1999). Because healthy hemlock stands filter rainwater, prevent soil erosion, limit light availability and algal productivity, and have a large effect on soil nutrient cycling, the loss of hemlock in the overstory is likely to be associated with a decline in surface water quality (Yorks et al. 1999). The impact of hemlock mortality on surface water quality is likely to be exacerbated by the tendency of eastern hemlock to grow along streambeds and in ravines (Whitney 1990). This could impact the management of watersheds providing municipal water supplies In southern New England, HWA has initiated a rapid shift from a coniferous to a deciduous forest, with black birch (Betula lenta L.), red maple (Acer rubrum L.) and various oaks (Quercus spp.) growing up beneath the dying hemlock canopy (Orwig and Foster 1998). Such a dramatic change in forest species composition could be detrimental for the hundreds of avian, mammal, aquatic, amphibious and understory plant species that depend on the unique micro-habitats created within hemlock stands (Evans et al. 1995). J. Pontius 5/04

Hemlock Decline Rating System J. Pontius 5/04 Hemlock Decline Rating System Healthy Pre-visual symptoms Decline/Recovery Cycle Final Decline

Hypotheses Citizen scientists will be able to monitor for the presence of hemlock woolly adelgid through out the state of New Hampshire using simple protocols Student groups can provide reliable ground truth for hemlock foliar health Student data will find a relationship between geographic and site location(slope and aspect) of a stand and infestation rates or hemlock health

Objectives Develop training protocols to collect data for a state monitoring system of HWA monitor stands for the presence or absence of HWA, growth rates, foliar health, and site characteristics Determine accuracy of plant stress glasses in detecting damaged needles and compare to hyperspectral data Determine the relationship between geographic and site location(slope and aspect) of a stand and infestation rates or hemlock health

Methods 1. Select ten schools/groups to monitor the health of their hemlock stands by determining: Location, GPS coordinates Presence of HWA or other pests (Report any occurrence of HWA to State DES or UNH Extension) Size and composition of stand Select 5 trees to monitor overall health (include height, DBH, canopy closure, live crown ratio, % new needle growth, stress glasses results) Slope and Aspect 2. Acquire Landsat TM satelite datasets and hyperspectral datasets (pre and post infestation) Have students compare above datasets to yearly ground truth data 3. Develop a Hemlock Health monitoring guide for easier identification of signs of HWA and other hemlock pests Send out printed copies to selected schools and put on Forest Watch and DES? websites

Anticipated results and summary A citizen scientist monitoring system for the presence of hemlock woolly adelgid and hemlock foliar health through out the state of New Hampshire will assist researchers Ground truth data for hemlock foliar health will be valid and useful in checking remotely sensed data (Forest Service) Student data may find a relationship between geographic and site location(slope and aspect) of a stand and infestation rates or hemlock health

Websites of Interest http://www.fs.fed.us/na/morgantown/fhp/hwa/other_links.htm main site http://www.fs.fed.us/na/morgantown/fhp/hwa/pdfs/mcclure_hwa.pdf http://na.fs.fed.us/wv/hwa/ bibliography Contact # in NH- 603/271-7858

Pawtuckaway State Park, NH “Unless an effective biological or chemical control is found that can be released on a massive scale that coincides with the range of HWA, hemlock may be eliminated across broad portions of its range in a few decades” (Orwig and Foster 1999)

Timeline Category Fall 04 Winter 05 Spring 05 Sum 05 Fall 05 Lit review Proposal work Submit proposal for grant funding Fieldwork/ school visits Monitor sites in program Meet with researchers from USDA forest service, State, UNH Implement monitoring program Analyze/report data to State