Dataset: Teatown Forest Inventory, Forest Plot Data, Canopy Coverage

Methods

The methods followed in the creation of the dataset, including description of field, laboratory and processing steps, and quality control procedures

Current Methods

• Canopy Coverage
  
  

  Canopy cover was estimated at each plot using a densiometer. Canopy cover was measured over the outer plot center, and over each subplot center, such that 5 total estimates within the plot were recorded. One record is recorded per plot facing plot center and at the center stake facing north.

Dataset Fields

Detailed documentation of the fields comprising the dataset, including the type of measurement, units where applicable, and any controlled vocabularies or code lists present in the data

Sampling Equipment

Equipment and software used to collect data, including how that equipment was used.

Current Equipment

• Teatown Forest Inventory, Forest Plot Design
  
  

  Sampling design: A total of 20 forest plot locations were marked in ArcGIS. These locations were investigated to determine if they fit the criteria for sampling, which included the following: forest type (oak dominated), slope (relatively flat or gradual), and dispersal across the preserve. Plot locations were relocated based on field observations if they did not fit the criteria. In total, 18 locations were selected for plot setup. Plots were set up and data collected for the first time in late summer/fall 2015. A circular nested plot design consisting of a 12.6 m radius (500 m2) outer plot and four 2.45 m radius (18.9 m2 x 4 = 75.4 m2) circular inner plots were installed (Figure 1). The center of the outer plot is marked with rebar. The centers of the inner plots are marked with green garden stakes and are located 6 m from the center of the outer plot at 90 degree angles from the center. The first inner plot location was selected at random; due to this, distance from the outer plot center may vary slightly due to the presence of rocks, roots or trees where the garden stakes were placed. The distance and orientation of the inner plots’ center from the center of the outer plot was recorded. In addition, four 12 m transects were laid out radiating from the outer plot center. Transects were oriented such that they fell between the inner plots. Transects were also at 90-degree angles to one another, and no permanent markers for the transects were installed. The orientations of the transects with respect to the center of the plot was recorded. In the outer plot, all trees and saplings were marked with permanent metal tags or temporary yellow plant tags. In 2021, all yellow tags were replaced with writable temporary metal tags. The yellow tags were written on with Sharpie, and weathering caused the tags to fade in the 5 years between sampling periods. All metal tags were placed on the tree such that they face the plot center. The size of the woody plant determined which tag type was used. Generally, any tree (>10 cm dbh; >1.4 m height) was marked with a metal tag, and any sapling (<10>1.4 m height) was marked with the temporary metal tag. All shrubs (<1.4 m height) were also marked with a yellow tag that was replaced with a temporary metal tags. Any shrub species that had more than one trunk was only marked with one tag. Shrubs that were reduced to <1.4m in height in a sampling period due to damage are not measured and their tag removed. Trees were defined as any species in the Burns and Honkala (1990). The full list of species considered trees or saplings (small trees) is below in Table 1.

Site Characteristics

The spatial extent of the dataset site coverage, and descriptions of the spatial extent and context for the data collection

• Site Description

  Teatown Lake Reservation