Forest Survey Can you identify this tree?
Red Maple
Research Methods- Sampling with Transect Line Why will we be using quadrats (plots) in the Idlewood Forest? (view quadrats on a transect line ) s_transects.html s_transects.html
Percentage, Quads, Random Sampling Fundamental Question in Ecology: Estimating the number of organisms in a certain place at a certain time.
Quadrat sampling – based on measurement of replicated sample units ; “quadrats” or “plots”. Allows “absolute density “= # of individuals / unit area within the study site
Terms: How Many? 1. Total Populations = total # of individuals of each species 2. Density = # of individuals of a species / unit area How Often? 3. Frequency = percentage (%) of times a species occurs in the sample quadrats How Much Stuff? 4. Biomass / Cover = amount of living material produced by a species (Total Diameters will be used to indicate Biomass of a tree species)
Quadrat Sampling explanation Then – Use the information on the “Combined Data Chart” to calculate: (directions, page 2) % Relative Density % Relative Frequency % Relative Biomass ---- for each tree species ---- *In order to compare each tree species with other species Later - “Importance Values” (directions, pg 4) are calculated using: 5. Total Populations = add up all trees for each species
12’ diameter Hemlock in Huntingdon Co., Pa
DBH The most common way to measure the abundance of trees is the "diameter at breast height" or DBH of individual trees. The DBH is the diameter of the tree's trunk at the height of the archetypal forester's 4.5 feet (1.37 m) Vegetation scientists can calculate diameter indirectly by measuring circumference. DBH Penn’s Woods Project, video (1:39) FIND YOUR DBH
Diameter Tapes Special measuring tapes are available that do the geometry for you. These "diameter tapes" are marked on one side in centimeters, on the other the diameter of a circle with a given circumference. The first step in using these diameter tapes is to calibrate "breast height" on your body.
Diameter Tape 2 Start using the tape to measure DBH by attaching its end at the proper breast-height Then stretch the tape around the trunk at breast height. Read diameter from the point that the tape overlaps zero on the tape.
What is the reading on this tape? 55.6 cm
A common mistake is using the wrong side of the tape. Remember, one side measures distance, just like any other tape. Don't use that side! Use the other side, which reads diameter when the tape is wrapped around a circular trunk.
Diameter of a Tree measurement Tree measurement using Biltmore Stick (10:12) (25” from Biltmore stick to eye) How to measure tree using tape (reading) ntent/HTM-trees.htm Diameter at breast height, DBH measurement (1:39)