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 Study Design

This page provides information on the overall design of the project, including study sites, treatment methods and sampling design. A more comprehensive description is available in The Hardwood Ecosystem Experiment: A Framework for Studying Responses to Forest Management.  

Study Sites

Harvesting Treatments

Sampling Design

Study Sites

Morgan-Monroe and Yellowwood State Forests

State forests study sites

Study sites were spread over Morgan-Monroe State Forest (MMSF) and Yellowwood State Forest (YSF) in south central Indiana. MMSF is over 9,712 hectares in Morgan and Monroe Counties, and was established in 1929. YSF encompasses over 9,439 hectares of Brown County and was created in 1940.

Management Units were established in MMSF and YSF. Each unit has a central research core area and a buffer area around this core. The units were created using existing DoF management tracts. Each research core was comprised of 2-3 management tracts, and tracts adjacent to these cores were designated as buffers. The size of the research cores and their buffer areas ranged from 364 ha (900 acres) to 405 ha (1000 acres). A total of 9 management units were established in MMSF and YSF. The 9 management units were randomly drawn from 11 possible areas. Each of the 9 units was then randomly assigned to a treatment, with 3 control units, 3 even-aged management units, and 3 uneven-aged management units.

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Harvesting Treatments


The three Management Units assigned to control will receive no harvest or burn treatments in the 200-acre Research Core for the duration of the study. The control units will be used to monitor variation in plant and animal populations and communities in the absence of active forest management.

Uneven-aged management units

Uneven-aged management within the designated Research Cores will consist of four 0.4 ha (1.0 ac), two 1.2 ha (3.0 ac), and two 2 ha (5.0 ac) openings. In the remaining area of the research core, single tree selection with a target basal area of 16.1 – 23.0 m2/ha (70 – 100 ft2/ac) will be marked. Single trees will not be marked within 15.2 m (50 ft) of the harvest area boundaries to avoid expanding the size of the openings. The harvest design for the Research Core was designed in consultation with HEE researchers. This treatment is to replicate the current silvicultural practices used at Morgan-Monroe and Yellowwood State Forests.

Even-aged management units

Even-aged management within the Research Core will consist of 4-hectare (10-acre) openings using clearcut and shelterwood harvesting methods. Four openings will be created; two openings will be clearcut and two will be shelterwood. The return interval for each opening will be 100 years. The total area harvested in the first year is 16 hectares per Core (48 hectares for the three even-aged Cores). Guidelines for best management practices will be followed.

Control chart
Uneven-aged chart
Control graph

Timber Sales

Timber was posted for closed bid on April 17, 2008 at Morgan-Monroe State Forest. To account for the variation in logging techniques (machinery, etc.), the units have been divided up into blocks which include a control, an uneven-aged, and an even-aged management unit (Table 1).

Table 1: Timber Sale Block Unit Assignments

Block Name Uneven Aged Unit Even-Aged Unit
Morgan-Monroe Unit 1 Unit 3
Yellowwood West Unit 8 Unit 6
Yellowwood East Unit 7 Unit 9

The Morgan-Monroe Block contained a total of 742,149 board feet of timber marked for sale. Yellowwood West had 425,978 board feet. Yellowwood East had 442,334 board feet.

Timber was sold in blocks, and the buyer agreed to use the same crew on both the uneven- and even-aged units within the block. Uneven-aged units could have started beginning July 14, 2008. Buyers were asked to begin harvesting as soon as possible. Uneven-aged unit harvests had to be completed and closed prior to harvesting in the even-aged unit. All harvesting had to be completed and closed by February 28, 2009. Best Management Practices were to be followed when applicable. Table 2 shows the approximate start date and close date for each unit.

Table 2: Harvest Dates and Equipment Used by Sale Block

  Uneven-Aged Unit Even-Aged Unit
Block Name Start Date Close Date Start Date Close Date
Morgan-Monroe 7-15-08 9-8-08 11-15-08 12-4-08
Yellowwood West 10-6-08 11-30-08 12-1-08 1-6-09
Yellowwood East 9-9-08 10-3-08 10-4-08 10-17-08

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Sampling Design

Vegetation Sampling

To monitor the growth and condition of the forest over time, a total of 716 vegetation inventory plots have been established across the nine HEE research units on a 75 x 75 meter grid. A broad range of data is collected at each plot including the diameter, species, light field, strata, condition, and location of overstory trees. Similar data is collected for saplings within the plots. In addition, decay class, height, and species is recorded for all snags (standing dead trees) within the plots. Data concerning herbaceous plants and seedlings is also recorded at these same plots. Full inventories of all plots are designed to follow a four-year schedule. Over time, this data will be used to calibrate regional growth and yield models, validate remotely sensed data, and be related to habitat analyses for wildlife and insect communities.

Animal Sampling

Species selected for study include a range of vertebrate taxa that represent both species of management concern and species indicative of microhabitat conditions and successional stages. Selected forest vertebrates will be monitored before and after management treatments to determine the impacts on individual, population and community levels. Surveys of breeding birds, small mammals, bats, and amphibians will target selected species of interest, but data will be collected on all species detected.

Survey techniques will be taxon-specific, and will combine efforts for species groups with similar detectabilities; for instance aural point counts for breeding birds. Live trapping will be used to determine population estimates of native rodents, whereas ultrasonic detection will be conducted for bats. Formal surveys will be augmented by visual searches and reports of incidental observations of selected species (e.g., box turtles, snakes). As with the vegetation sampling, survey plots for all taxa will include the harvest opening, the adjacent forest edge, and the uncut forest extending away from the openings into the 200-acre core areas.

In addition to vertebrate species sampling, an important aspect of the project is the invertebrate component. Longhorned beetles and moth species are also being collected to determine the affects of timber management on their populations.

Social Sampling

Many attitudes and values toward forest management are held by stakeholders. We aim to better understand attitudes toward forest management practices and policies, to engage stakeholders and decision-makers in dialogue, and to design outreach programs aimed at affecting the attitudes and behavior of recreational visitors and landowners living adjacent to or near the Morgan-Monroe State Forest. The sample for this component of the research consists of neighboring landowners and recreational visitors to the forest.

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