Data Archive

HF412

Harvard Forest Schoolyard Data since 2004

Related Publications

Data

HF412-01: schools (preview)
HF412-02: field sites (preview)
HF412-03: site surveys (preview)
HF412-04: tree species (preview)
HF412-05: fall phenology (preview)
HF412-06: spring phenology (preview)
HF412-07: hwa (preview)
HF412-08: vernal pool (preview)
HF412-09: stream (preview)
HF412-10: forest (preview)

Overview

Lead: Emery Boose, Pamela Snow, Katharine Hinkle, Clarisse Hart, John O'Keefe, David Orwig, Elizabeth Colburn, Greta VanScoy, Edward Faison, Audrey Barker Plotkin, Ann Lewis
Investigators:
Contact: Information Manager
Start date: 2004
End date: 2025
Status: ongoing
Location: Eastern United States
Latitude: +32.74 to +44.02 degrees
Longitude: -83.77 to -69.97 degrees
Elevation: 0 to 600 meter
Datum: WGS84
Taxa:
Release date: 2026
Language: English
EML file: knb-lter-hfr.412.5
DOI: digital object identifier
EDI: data package
DataONE: data package
Related links:

Study type: long-term measurement
Research topic: biodiversity studies; invasive plants, pests and pathogens; physiological ecology, population dynamics and species interactions; watershed ecology
LTER core area: primary production, population studies, disturbance patterns
Keywords: climate, hemlock, hemlock woolly adelgid, hydrology, invasive species, phenology, trees, wetlands
Abstract:
In the Harvard Forest Schoolyard program, HF ecologists work directly with teachers from public and private schools across New England (and the eastern U.S.) to learn about and initiate ecological research in their classrooms and schoolyards. More than 3500 students each year from grades 4-12 participate in authentic, field-based research projects that address current and important environmental issues. Projects to date have included tree phenology, the hemlock woolly adelgid, vernal pools, intermittent streams, and long-term forest plots. Participating schools submit data to an online database on the Harvard Forest website where the data are reviewed by HF staff and then made freely available for download and for graphing online. The project is supported by the National Science Foundation, the Highstead Foundation, the Salata Institute for Climate and Sustainability at Harvard University, and private donors.

For current data, please see: https://harvardforest2.fas.harvard.edu/asp/hf/php/k12/k12_project.php.
Methods:
1. Buds, Leaves and Global Warming

This project is designed for students in grades 4-12 to answer these long-term study questions: How long is the growing season in our schoolyard? How might the length of the growing season be related to climate? When does the growing season for trees in our schoolyard end in autumn, and when does the new growing season begin in spring?

Project Objectives: 1. Students learn how to do field research by participating in a program associated with the Harvard Forest. 2. Teacher and students collect field data seasonally. 3. Data is submitted to an online database managed at HF to share publicly. 4. The autumn and spring protocols can be combined to monitor the length of the growing season at each schoolyard. Annual data submission allows for cross-site comparison across participating schools to see how a changing climate may affect the length of the growing season in the local area and how the local area compares with other areas.

Field Time: A minimum of 8 data collection field visits annually: 4 times weekly beginning in mid to late September, and 4 times weekly beginning in early to mid-April. More visits are recommended to tell a more complete story about how the timing of the growing season is changing over time. We recommend that in autumn students continue monitoring trees until all study leaves have turned brown or dropped, and in spring, students monitor trees until all study buds have burst and leaves have mostly developed.

2. Woolly Bully: The Invasive Pest, the Hemlock Woolly Adelgid

This project is designed for students in grades 4-12 to answer these long-term study questions: Will the hemlock woolly adelgid (HWA) destroy our hemlock trees forever? How will our forest change if hemlock disappears? Concrete concepts and questions for here and now: Is the hemlock woolly adelgid currently present in our local field site? If so, is the population of HWA increasing or decreasing this year? Is HWA affecting our hemlock trees and/or surrounding forest now?

Project Objectives: 1. Students learn how to do field research by participating in a program associated with the Harvard Forest. 2. Teacher and students collect field data seasonally. 3. Data is submitted to an online database managed at HF to share publicly. 4. The autumn tree growth data and spring adelgid population and tree health data are combined to monitor the presence of the invasive insect and the related impact to the health of study trees at each schoolyard site. Annual data submission allows for cross-site comparison across participating schools to see how this invasive insect is impacting a foundation species distribution and wildlife habitat of our forests, both locally and regionwide.

Field Time: A minimum of 2 field visits annually: tree growth measurements in September and HWA sampling in late winter/spring. One visit in early September to introduce the field study and field site and to measure new growth. One visit in winter or spring. From late November through Spring, new woolly egg sacs are potentially visible if HWA is present.

3. Water in the Landscape: Vernal Pools

This project is designed for students in grades 4-12 to answer these long-term study questions: How do water levels in vernal pools vary over time, and how do those water level variations change between years and with differences in weather? How might such variations affect plants and animals that live in vernal pools? How do water levels of our vernal pool change seasonally this year?

Project Objectives: 1. Students learn how to do field research by participating in a program associated with the Harvard Forest. 2. Teacher and students collect field data seasonally. 3. Data is submitted to an online database managed at HF to share publicly. 4. Students monitor seasonal water level changes in the vernal pool. Sharing of information among schools looking at pools with different flood timing and duration shows how much variation there is in vernal pool hydrology.

Field Time: A minimum of 4 field visits annually: 1. September prior to leaf drop, 2. late November after leaf drop, 3. Late March or early April, after snowmelt, and 4. once in June before the end of the schoolyear. Schools are recommended to collect data more often to better track short-term changes in water levels after weather events such as rainstorms, as well as to track longer-term seasonal changes.

4. Water in the Landscape: Streams

This project is designed for students in grades 4-12 to answer these long-term study questions: How do water levels in intermittent streams vary over time, and how do those water level variations change between years and with differences in weather? How might such variations affect plants and animals that live in intermittent streams? How did water levels of our stream change seasonally this year?

Project Objectives: 1. Students learn how to do field research by participating in a program that was associated with the Harvard Forest. 2. Teacher and students collect field data seasonally. 3. Data is submitted to an online database managed at HF to share publicly. 4. Students monitor seasonal water level changes in the stream. Sharing of information among schools shows how much variation there is in stream hydrology. These data can help show changes in streamflow seasonally and in relation to climate.

Field Time: A minimum of 4 field visits annually: 1. September prior to leaf drop, 2. Late November after leaf drop, 3. Late March or early April after snowmelt, and 4. once in June before the end of the schoolyear. Schools are recommended to collect data more often to better track short-term changes in water levels and stream flow after weather events such as rainstorms, as well as to track longer-term seasonal changes.

5. Our Changing Forests

This project is designed for students in grades 7-12 to answer these long-term study questions: How do forests grow and change over time in response to different environments and land use? How will forest composition and growth respond to future natural and human-caused disturbances? More specific study questions include: What are the growth rates of trees in the forest? How do they differ among different species and different sized individuals? How fast are trees of different species and size accumulating diameter growth and carbon from year to year within a site and on sites with different histories and soil moisture? How does the tree composition differ in forests with different land-use histories or environments? Under what conditions do different tree species grow best?

Project Objectives: 1. Students learn how to do field research by participating in a program associated with the Harvard Forest. 2. Teacher and students collect field data annually. 3. Data is submitted to an online database managed at HF to share publicly. 4. Field site survey data and tree measurement data are combined to monitor how the composition of the wooded study sites grow and change over time. Complimentary activities look further at how the landscape in the local town and region has changed in the past, and how current-day forests will change over time. Activities include data collection, measurement, plant identification, and data analysis including calculation of carbon storage. Annual data submission allows for cross-site comparison across participating schools to compare the dynamics of local woodlands to other sites in the region that encompass diverse land-use histories.

Field Time: A minimum of 2 field visits annually. Visits are normally done in autumn but may be done in other seasons as fits the course schedules of individual schools and sites. One or more visits includes gathering field site survey data encompassing wildlife sign, invasive species, rock and water cover, slope, canopy cover, etc. The other major field activity involves tree identification and diameter measurements for each study plot.
Organization: Harvard Forest. 324 North Main Street, Petersham, MA 01366, USA. Phone (978) 724-3302. Fax (978) 724-3595.
Project: The Harvard Forest Long-Term Ecological Research (LTER) program examines ecological dynamics in the New England region resulting from natural disturbances, environmental change, and human impacts. (ROR).
Funding: National Science Foundation LTER grants: DEB-8811764, DEB-9411975, DEB-0080592, DEB-0620443, DEB-1237491, DEB-1832210. Other funding: Highstead Foundation, Salata Institute for Climate and Sustainability at Harvard University, Anonymous donor.
Use: This dataset is released to the public under Creative Commons CC0 1.0 (No Rights Reserved). Please keep the dataset creators informed of any plans to use the dataset. Consultation with the original investigators is strongly encouraged. Publications and data products that make use of the dataset should include proper acknowledgement.
License: Creative Commons Zero v1.0 Universal (CC0-1.0)
Citation: Boose E, Snow P, Hinkle K, Hart C, O'Keefe J, Orwig D, Colburn E, VanScoy G, Faison E, Barker Plotkin A, Lewis A. 2026. Harvard Forest Schoolyard Data since 2004. Harvard Forest Data Archive: HF412 (v.5). Environmental Data Initiative: https://doi.org/10.6073/pasta/0c3b522cf8c250c94bd826bc53ebd269.

Detailed Metadata

HF412-01: schools

school.code: school code
school.name: school name
teachers: teacher last name
street.address: street address
town: town
state: state
latitude: latitude (unit: degree / missing value: NA)
longitude: longitude (unit: degree / missing value: NA)
elevation: elevation (unit: meter / missing value: NA)
buds: buds status
- A: active
- I: inactive
- N: not participating
hwa: hwa status
- A: active
- I: inactive
- N: not participating
vernal: vernal pool status
- A: active
- I: inactive
- N: not participating
stream: stream status
- A: active
- I: inactive
- N: not participating
forest: forest status
- A: active
- I: inactive
- N: not participating

HF412-02: field sites

site.code: site code
school.code: school code
project.code: project code
site.id: site id
start.year: start year
end.year: end year
loc: location
- on-site: on school property
- off-site: off school property
latitude: latitude (unit: degree / missing value: NA)
longitude: longitude (unit: degree / missing value: NA)
elevation: elevation (unit: meter / missing value: NA)
town: town
state: state
land.use: land use
- natural: not landscaped / native vegetation
- edge: boundary
- modified: landscaped / non-native vegetation
site.notes: site notes

HF412-03: site surveys

site.code: site code
teacher: teacher last name
date: date of observation
landscape.position: landscape position
- ridge-hilltop: Ridgetop or hilltop
- hillside-upper: Hillside upper
- hillside-lower: Hillside lower
- dry-flat: Dry flat
- wet-flat: Wet flat
- rolling-upland: Rolling upland
asp: aspect (unit: degree / missing value: NA)
slope: slope
- none: None (0%)
- slight: Slight (1-4%)
- moderate: Moderate (5-15%)
- steep: Steep (>15%)
rock.cover: rock cover
- roc-00-00: <1%
- roc-01-05: 1-5%
- roc-06-25: 6-25%
- roc-26-50: 26-50%
- roc-51-75: 51-75%
- roc-76-100: >75%
water: water
- none: None
- stream: Stream
- seasonal-stream: Seasonal Stream
- wetland: Wetland
- vernal-pool: Vernal pool
- flooded-area: Flooded area
- other: Other
canopy.cover: canopy cover
- can-00-09: <10%
- can-10-25: 10-25%
- can-26-50: 26-50%
- can-51-75: 51-75%
- can-76-100: >75%
pest.pathogens: pests / pathogens
- none: None
- ash-yellow: Ash yellows/decline
- asian-long: Asian long-horned beetle
- balsam-adelgid: Balsam woolly adelgid
- beech-bark: Beech bark disease
- butternut-canker: Butternut canker
- chestnut-blight: Chestnut blight
- emerald-ash: Emerald ash borer
- gypsy-moth: Lymantra dispar
- hemlock-borer: Hemlock borer
- hemlock-scale: Hemlock elongate scale
- hemlock-adelgid: Hemlock woolly adelgid
- spruce-budworm: Spruce budworm
- blister-rust: White pine blister rust
- winter-moth: Winter moth
- other: Other
human.activity: human activity
- none: None
- barbed-wire: Barbed Wire
- cellar-hole: Cellar Hole
- cut-stumps: Cut Stumps
- footpath: Footpath
- forest-road: Forest Road
- highway: Highway
- building-complex: Building Complex
- open-tree: Open-Grown Trees
- logging-scar: Logging Scar On Tree
- multiple-trunk: Multiple-Trunked Trees
- open-field: Open Field
- paved-road: Paved Road
- house: Residential House
- skid-trail: Skid Trail
- stone-wall: Stone Wall
- woods-cabin: Woods Cabin
- other: Other
weather.events: weather events
- none: None
- burn-scar: Burn scar with charcoal
- broken-canopy: Deformed/broken canopy
- downed-branches: Large downed branches
- pit-mound: Pit and mound topography
- river-deposits: River flood deposits
- snapped-trees: Snapped trees
- uprooted-trees: Uprooted trees
- other: Other
debris.cover: debris cover
- deb-00-00: <1%
- deb-01-05: 1-5%
- deb-06-25: 6-25%
- deb-26-50: 26-50%
- deb-51-75: 51-75%
- deb-76-100: >75%
wildlife.sign: wildlife sign
- none: None
- antler-rubbing: Antler rubbing (deer/moose)
- bark-stripping: Bark stripping (deer/moose)
- deer-moose-browse: Browsing (deer/moose)
- porcupine-browse: Browsing (porcupine)
- rabbit-browse: Browsing (rabbit/hare)
- claw-marks: Claw marks on beech (black bear)
- felled-trees: Felled trees (beaver)
- woodpecker-holes: Holes in trees (woodpecker)
- deer-pellets: Pellet piles (deer)
- moose-pellets: Pellet piles (moose)
- other: Other
invasive.plants: invasive plants
- none: None
- autumn-olive: Autumn olive
- buckthorn: Buckthorn
- burning-bush: Burning bush
- garlic-mustard: Garlic mustard
- honeysuckle: Honeysuckle shrub/vine
- barberry: Japanese barberry
- stilt-grass: Japanese stilt grass
- multiflora-rose: Multiflora rose
- bittersweet: Oriental bittersweet
- other: Other
survey.notes: survey notes

HF412-04: tree species

species.code: species code
species.name: common name
scientific.name: scientific name

HF412-05: fall phenology

site.code: site code
teacher: teacher last name
date: date of observation
julian: day of year (unit: nominalDay )
tree.id: tree id
species.code: species code
- AD: Alt-Leaved Dogwood
- AL: Speckled Alder
- AP: Apple
- AS: American Sycamore
- BA: Black Ash
- BB: Black Birch
- BC: Black Cherry
- BE: Beech
- BG: Black Gum
- BH: Bitternut Hickory
- BL: Black Locust
- BN: Black Walnut
- BO: Black Oak
- BP: Beach Plum
- BS: Black Spruce
- BT: Buckthorn
- BU: Butternut
- BW: Basswood
- BX: Box Elder (Ash Maple)
- CA: Chinese Arborvitae
- CC: Choke Cherry
- CH: Chestnut
- CO: Chestnut Oak
- CT: Catalpa
- CW: Cottonwood
- EB: Black Elderberry
- EC: Exotic Cherry
- EL: American Elm
- ES: English Elm
- FD: Flowering Dogwood
- GA: Green Ash
- GB: Gray Birch
- GD: Gray Dogwood
- GK: Ginkgo
- HA: Hawthorn
- HB: Highbush blueberry
- HL: Honey Locust
- HO: Hornbeam
- IW: Ironwood
- JP: Japanese Pagoda
- KC: Kentucky Coffee Tree
- LA: Largetoothed Aspen
- LB: Northern Spicebush
- LL: Lilac
- LR: Larch
- MA: Mountain Ash
- MB: Maleberry
- MC: Manchurian Maple
- MM: Mountain Maple
- MR: Red Mulberry
- MS: Sycamore Maple
- NM: Norway Maple
- NS: Norway Spruce
- OO: Osage Orange
- OS: Swamp White Oak
- PC: Pin Cherry
- PE: Pear
- PH: Pignut Hickory
- PM: Paperbark Maple
- PO: Pin Oak
- PP: Pitch Pine
- PR: Peach
- RB: River Birch
- RC: Red cedar
- RE: Red Bud
- RM: Red Maple
- RO: Red Oak
- RP: Red Pine
- RS: Red Spruce
- SA: Sassafras
- SB: Serviceberry (Shadbush)
- SC: Scrub Oak
- SE: Siberian Elm
- SG: Sweet Gum
- SH: Shagbark Hickory
- SL: Slippery Elm
- SM: Sugar Maple
- SO: Scarlet Oak
- SP: Scotch Pine
- SR: Star Magnolia
- SS: Staghorn Sumac
- ST: Striped Maple
- SV: Silver Maple
- SW: Japanese Stewartia
- TA: Trembling Aspen
- TP: Tulip Popular
- TS: Hemlock
- VM: Virginia Magnolia
- WA: White Ash
- WB: White Birch
- WH: Witch Hazel
- WI: Willow
- WK: Willow Oak
- WM: White Mulberry
- WO: White Oak
- WP: White Pine
- WS: White Spruce
- X1: Unidentified
- YB: Yellow Birch
- YW: Yellow Wood
total.leaves: number of observable leaves (unit: number / missing value: NA)
fallen.leaves: number of fallen leaves (unit: number / missing value: NA)
tree.color: tree color
- 1: 0-25%
- 2: 26-50%
- 3: 51-75%
- 4: 76-100%

HF412-06: spring phenology

site.code: site code
teacher: teacher last name
date: date of observation
julian: day of year (unit: nominalDay )
tree.id: tree id
species.code: species code
- AD: Alt-Leaved Dogwood
- AL: Speckled Alder
- AP: Apple
- AS: American Sycamore
- BA: Black Ash
- BB: Black Birch
- BC: Black Cherry
- BE: Beech
- BG: Black Gum
- BH: Bitternut Hickory
- BL: Black Locust
- BN: Black Walnut
- BO: Black Oak
- BP: Beach Plum
- BS: Black Spruce
- BT: Buckthorn
- BU: Butternut
- BW: Basswood
- BX: Box Elder (Ash Maple)
- CA: Chinese Arborvitae
- CC: Choke Cherry
- CH: Chestnut
- CO: Chestnut Oak
- CT: Catalpa
- CW: Cottonwood
- EB: Black Elderberry
- EC: Exotic Cherry
- EL: American Elm
- ES: English Elm
- FD: Flowering Dogwood
- GA: Green Ash
- GB: Gray Birch
- GD: Gray Dogwood
- GK: Ginkgo
- HA: Hawthorn
- HB: Highbush blueberry
- HL: Honey Locust
- HO: Hornbeam
- IW: Ironwood
- JP: Japanese Pagoda
- KC: Kentucky Coffee Tree
- LA: Largetoothed Aspen
- LB: Northern Spicebush
- LL: Lilac
- LR: Larch
- MA: Mountain Ash
- MB: Maleberry
- MC: Manchurian Maple
- MM: Mountain Maple
- MR: Red Mulberry
- MS: Sycamore Maple
- NM: Norway Maple
- NS: Norway Spruce
- OO: Osage Orange
- OS: Swamp White Oak
- PC: Pin Cherry
- PE: Pear
- PH: Pignut Hickory
- PM: Paperbark Maple
- PO: Pin Oak
- PP: Pitch Pine
- PR: Peach
- RB: River Birch
- RC: Red cedar
- RE: Red Bud
- RM: Red Maple
- RO: Red Oak
- RP: Red Pine
- RS: Red Spruce
- SA: Sassafras
- SB: Serviceberry (Shadbush)
- SC: Scrub Oak
- SE: Siberian Elm
- SG: Sweet Gum
- SH: Shagbark Hickory
- SL: Slippery Elm
- SM: Sugar Maple
- SO: Scarlet Oak
- SP: Scotch Pine
- SR: Star Magnolia
- SS: Staghorn Sumac
- ST: Striped Maple
- SV: Silver Maple
- SW: Japanese Stewartia
- TA: Trembling Aspen
- TP: Tulip Popular
- TS: Hemlock
- VM: Virginia Magnolia
- WA: White Ash
- WB: White Birch
- WH: Witch Hazel
- WI: Willow
- WK: Willow Oak
- WM: White Mulberry
- WO: White Oak
- WP: White Pine
- WS: White Spruce
- X1: Unidentified
- YB: Yellow Birch
- YW: Yellow Wood
total.buds: number of observable buds (unit: number / missing value: NA)
open.buds: number of open buds (unit: number / missing value: NA)
leaf.length: leaf length (unit: centimeter / missing value: NA)

HF412-07: hwa

site.code: site code
teacher: teacher last name
date: date of observation
julian: day of year (unit: nominalDay )
tree.id: tree id
health: tree health
- 0: healthy--all green
- 1: some bare branches
- 2: unhealthy--half or more bare branches
- 3: dead--no green needles--cause unspecified
- 4: dead--killed by HWA
- 5: dead--cut down because of HWA
- 6: dead--removed for reasons other than HWA
wool: presence of hemlock woolly adelgid
- 0: absent
- 1: present
eggs: average number of egg sacks per branch (unit: number / missing value: NA)
growth: average new growth at branch tips (unit: centimeter / missing value: NA)

HF412-08: vernal pool

site.code: site code
teacher: teacher last name
date: date of observation
julian: day of year (unit: nominalDay )
max.diameter: maximum pool diameter (unit: meter / missing value: NA)
diameter: pool diameter (unit: meter / missing value: NA)
depth: pool depth (unit: centimeter / missing value: NA)
air.temp: air temperature (unit: celsius / missing value: NA)
water.temp: water temperature (unit: celsius / missing value: NA)

HF412-09: stream

site.code: site code
teacher: teacher last name
date: date of observation
julian: day of year (unit: nominalDay )
depth: water depth (unit: centimeter / missing value: NA)
flow.rate: rate of flow
- 1: continuously flowing
- 2: flowing areas interrupted by areas without water
- 3: quiet pools interrupted by areas without water
- 4: damp channel--no water
- 5: dry channel
- 6: no channel visible
air.temp: air temperature (unit: celsius / missing value: NA)
water.temp: water temperature (unit: celsius / missing value: NA)

HF412-10: forest

site.code: site code
teacher: teacher last name
date: date of observation
julian: day of year (unit: nominalDay )
survey: survey number
tree.id: tree id
species.code: species code
- AD: Alt-Leaved Dogwood
- AL: Speckled Alder
- AP: Apple
- AS: American Sycamore
- BA: Black Ash
- BB: Black Birch
- BC: Black Cherry
- BE: Beech
- BG: Black Gum
- BH: Bitternut Hickory
- BL: Black Locust
- BN: Black Walnut
- BO: Black Oak
- BP: Beach Plum
- BS: Black Spruce
- BT: Buckthorn
- BU: Butternut
- BW: Basswood
- BX: Box Elder (Ash Maple)
- CA: Chinese Arborvitae
- CC: Choke Cherry
- CH: Chestnut
- CO: Chestnut Oak
- CT: Catalpa
- CW: Cottonwood
- EB: Black Elderberry
- EC: Exotic Cherry
- EL: American Elm
- ES: English Elm
- FD: Flowering Dogwood
- GA: Green Ash
- GB: Gray Birch
- GD: Gray Dogwood
- GK: Ginkgo
- HA: Hawthorn
- HB: Highbush blueberry
- HL: Honey Locust
- HO: Hornbeam
- IW: Ironwood
- JP: Japanese Pagoda
- KC: Kentucky Coffee Tree
- LA: Largetoothed Aspen
- LB: Northern Spicebush
- LL: Lilac
- LR: Larch
- MA: Mountain Ash
- MB: Maleberry
- MC: Manchurian Maple
- MM: Mountain Maple
- MR: Red Mulberry
- MS: Sycamore Maple
- NM: Norway Maple
- NS: Norway Spruce
- OO: Osage Orange
- OS: Swamp White Oak
- PC: Pin Cherry
- PE: Pear
- PH: Pignut Hickory
- PM: Paperbark Maple
- PO: Pin Oak
- PP: Pitch Pine
- PR: Peach
- RB: River Birch
- RC: Red cedar
- RE: Red Bud
- RM: Red Maple
- RO: Red Oak
- RP: Red Pine
- RS: Red Spruce
- SA: Sassafras
- SB: Serviceberry (Shadbush)
- SC: Scrub Oak
- SE: Siberian Elm
- SG: Sweet Gum
- SH: Shagbark Hickory
- SL: Slippery Elm
- SM: Sugar Maple
- SO: Scarlet Oak
- SP: Scotch Pine
- SR: Star Magnolia
- SS: Staghorn Sumac
- ST: Striped Maple
- SV: Silver Maple
- SW: Japanese Stewartia
- TA: Trembling Aspen
- TP: Tulip Popular
- TS: Hemlock
- VM: Virginia Magnolia
- WA: White Ash
- WB: White Birch
- WH: Witch Hazel
- WI: Willow
- WK: Willow Oak
- WM: White Mulberry
- WO: White Oak
- WP: White Pine
- WS: White Spruce
- X1: Unidentified
- YB: Yellow Birch
- YW: Yellow Wood
health: tree health
- 0: dead
- 1: living
dbh: diameter at breast height (unit: centimeter / missing value: NA)