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Harvard Forest Data Archive
Simulating Intrastand Movement of Hemlock Woolly Adelgid at Harvard Forest 2009Related Publications
- hf198-01: plotmap (preview)
- hf198-02: amount of powder trapped of each color for the two sampling periods
- hf198-03: R code used to fit dispersal probability density functions using maximum likelihood.
- Lead: Matt Fitzpatrick, Evan Preisser
- Investigators: Aaron Ellison, Jenna Turner
- Contact: Matt Fitzpatrick
- Start date: 2009
- End date: 2009
- Status: completed
- Location: Simes Tract (Harvard Forest)
- Latitude: +42.47 to +42.48
- Longitude: -72.22 to -72.21
- Elevation: 200 meter
- Taxa: Adelges tsugae (hemlock woolly adelgid)
- Release date: 2012
- EML file: knb-lter-hfr.198.6
- DOI: digital object identifier
- Related links:
- Study type: short-term measurement, modeling
- Research topic: ecological informatics and modelling; invasive plants, pests and pathogens; regional studies
- LTER core area: populations, disturbance
- Keywords: hemlock, hemlock woolly adelgid, invasive species, modeling, simulation
The hemlock woolly adelgid (HWA), Adelges tsugae Annand (Hemiptera: Adelgidae), has spread rapidly across the eastern USA since its introduction from Japan 60 years ago, causing widespread mortality of both eastern hemlock [Tsuga canadensis (L.) Carriere] and Carolina hemlock [Tsuga caroliniana Engelm. (Pinaceae)]. Although HWA spread patterns have been repeatedly analyzed at regional scales, comparatively little is known about its dispersal potential within and between hemlock stands. As the small size and clonal nature of HWA make it nearly impossible to identify the source populations of dispersing individuals, we simulated intrastand HWA movement in the field by monitoring the movement of clumps of fluorescent powder that are slightly larger than HWA, but much easier to detect in the forest understory. Using three hemlock trees with three colors of fluorescent powder as source populations, we detected dispersal events at the farthest distances within our trapping array (400 m). However, more than 90% of dispersal events were less than 25 m. Dispersal patterns were similar from all three source trees and the distribution of dispersal distances in all cases could be described by lognormal probability density functions with mean dispersal distance of 12-14 m, suggesting that dispersal was relatively independent of location of source trees. In general, we documented tens of thousands of passive dispersal events in the forest understory despite the presence of a dense forest canopy. Thus, even under relatively light-wind conditions, particles of similar dimensions to HWA are capable of intra-stand movement, suggesting that a large population of HWA could rapidly infest other trees within several hundred meter radius, or beyond.
For detailed methods, please see: Turner, J. L., M. C. Fitzpatrick, and E. L. Preisser. 2011. Simulating the dispersal of hemlock woolly adelgid in the temperate forest understory. Entomologia Experimentalis et Applicata 141:216–223.
This dataset is released to the public under Creative Commons license CC BY (Attribution). Please keep the designated contact person informed of any plans to use the dataset. Consultation or collaboration with the original investigators is strongly encouraged. Publications and data products that make use of the dataset must include proper acknowledgement.
Fitzpatrick M, Preisser E. 2012. Simulating Intrastand Movement of Hemlock Woolly Adelgid at Harvard Forest 2009. Harvard Forest Data Archive: HF198.
- id: id
- x: x coordinate (unit: meter / missing value: NA)
- y: y coordinate (unit: meter / missing value: NA)
hf198-02: amount of powder trapped of each color for the two sampling periods
- Format: text file
- Type: text file
hf198-03: R code used to fit dispersal probability density functions using maximum likelihood.
- Format: R code
- Type: R code