Timber Harvest and the Effect on Ruffed Grouse Habitat

Introduction: The Western Upper Peninsula of Michigan is an area well known for its wildlife and timber

harvest. These two influence each other heavily, and not always in a positive fashion. An

ongoing battle between foresters and wildlife managers occurs due to this relationship. Foresters

focus primarily on timber harvests and maintaining the sustainability of the area’s forests, while

wildlife managers focus more upon the animals that inhabit the forests. The primary animal of

importance in this project is the Ruffed Grouse. Ruffed Grouse typically dwell in aspen stands

from twenty to fifty years of age. These same aspen stands are desired for industrial timber

harvest. Timber harvest is important to foresters because it creates revenue and many products

such as furniture, paper, and plywood. This project aims to show the spatial relationship between

timber harvest and Ruffed Grouse habitat, and how they interact with each other.

The purpose of this model is to first, identify suitable locations for timber harvest. Locations

are deemed suitable if they meet certain criteria. If it is publically owned land, harvest must

occur 100 feet from major water bodies, the stands must be larger than twenty acres, older than

fifty years old, and must have a well-drained soil type (well-drained loamy sand, well-drained

loam, well-drained sandy loam). If the land is classified as industrial, harvest must occur 100 feet

from major water bodies and the trees must be older than forty years of age. The second step will

be to identify the projected volume and area of the harvested timberlands. The third step will be

to identify the impact timber harvest will have on Ruffed Grouse habitat by comparing high,

medium and low habitat before timber harvest (2015) and after timber harvest (2025). High

quality habitat is consists of aspen stands less twenty years old, adjacent to aspen stands greater

than fifty years old. Medium quality habitat is classified as aspen stands less than twenty years

old, adjacent to old oaks stands. Low quality habitat is classified as aspen stands less than twenty

years old that are not adjacent to old aspen or oak. This data will be mapped graphically and

tabularly to gauge the impact a timber harvest could have on Ruffed Grouse habitat before and

after timber harvest. This model should answer the following five questions:

1. How much area (in acres) of aspen is there in state-owned public and industrial forests?

2. How much area of aspen will be harvested?

3. How much volume of timber will be harvested from state-owned public and industrial

private forests?

4. How much area can be considered potential Ruffed Grouse habitat prior to timber

harvest?

5. Does the amount of potential Grouse habitat increase or decrease following

implementation of the timber harvest plan? By how much?

Methods: This data model was represented in ESRI’s ArcCatalog using a geodatabase. The

geodatabase was titled Timber_Harvest.gdb. Vector data was used because raster would not suit

our purpose for most of the data. Our database will be formatted as follows in table 1. Question

one was calculated through the use of select by attribute tool by selecting the aspen that is

located on industrial or state-owned public lands. Question two is a continuation of the select by

attribute process from question one but then also adding a one-hundred foot buffer around

hydrology lines. Using the erase tool, the overlap can be deleted between the buffer and the state

owned and public land that contains aspen. Finally, harvested aspen on industrial and state-

owned lands can be calculated through the use of the select by attribute tool by following the

harvested lands criteria (previously mentioned). Question three was calculated with the use of the

field calculator within the attribute tables for industrial and state-owned private lands by

multiplying the volume and the area with an answer in cords per acres. Question four was

calculated with the use of the select by attribute tool and select by location tool by follow the

high, medium, and low criteria (previously mentioned). Question five is the same process as

question four, except a field must be created to take all the harvested lands and add 10 years to

calculate ruffed grouse habitat post timber harvest. Non spatial data was acquired in a Microsoft

Excel file and was joined into the Forests feature class

Geodatabase design for Timber Harvest Data Model

Table 1

GeodatabaseFeature Dataset

Feature Class

Class Type Field Name Field Type Sample Value

Possible Domain

Type Acceptable ValuesKeys / Joins

Stand ID long integer 2344066Vegatation_Type

Text (10 characters) Aspen Coded Aspen, Oak

Acres double 12.02 acresAge short integer 40 years Ranged <20, >20, <50, >50 Join

Soil_TypeText (35 characters)

well-drained loamy sand Coded

Well-Drained Loamy Sand, Well-Drained Loam, Well-Drained Sandy Loam Join

Ownershiptext (45 characters) Public Coded

Public, Industry, Private (no private) Join

Shape_Area Double 123123.9923Shape_Length Double 1231.4123

Stand_ID short integer 123Primary Key

Area double 12.02 Acres

QualityText (10 characters) High Coded High, Medium, Low

Hydrology Lines Length double 12.02 ft Hydro_Clip

FID short integer 2131Shape length DoubleShape Area Double

Stand_ID short integer 123Foreign Key

Veg_TypeText (10 characters) Aspen Coded Aspen, Oak Join

Soil_TypeText (35 characters)

well-drained loamy sand Coded

Loamy Sand, Well-Drained Loam, Well-Drained Sandy Loam Join

Ownershiptext (45 characters) Public Coded

Public, Industry, Private (no private) Join

Non-Spatial Data

Stand_Data

Timber_Harvest.gdb

Timber_Harvest_Features

Table

PolygonStudy Area

Grouse Habitat

Forests Polygon

Polygon

Results: As listed on Table 1, there is a total of 5,583

acres to be harvested; producing 124,878 cords of

wood on state-owned public lands. Industrial lands on

the other hand will have about 355 acres harvested, producing 6,596 acres (Table 1). Prior to

harvest (2015), high quality habitat comprises about 4,773 acres of land which is 13% (table 3)

of the habitable area, while after harvest (2025) it will make up 6329.4 acres which is 22.98%

(Table 3) of habitable areas. This is an increase in high quality habitat of about 9.67% (table 3)

and a percent change of 32.6% (table 3) between 2015 and 2025. Medium quality habitat prior to

timber harvest totals about 1036 acres which is 2.9% of the total habitable lands and 1061.7 acres

or 3.85% of the habitable lands after

harvest (Table 3). Medium quality habitat

increased by 0.96% between 2015 and

2025. This is a percent change of 2.4%

(table 3). Low quality habitat makes up

30074 acres of land or 83.8% of habitable

area before timber harvest as opposed to

20156.6 acres or 73.17% of the habitable

lands after harvest (table 3). This is a decrease of 10.64% of low quality habitat from 2015 to

2025 and illustrates a percent change of -32.98% (table 3). Overall this timber harvest will

decrease ruffed grouse habitat in Marquette and Dickinson County by about 8337 acres of land,

which is a -23.23 percent change (table 23 from 2015 to 2025. The locations of different quality

of habitats in 2015 and 2025 can be seen graphically on Map 1.

Table 2

Table 3

Ownership Area (Acres) Volume (Cords)State Public 5583.7 124878.5Industrial 355.2 6596.4Total 5938.9 131474.9

Industrial and State-Owned Public Aspen Harvest

Habitat Quality 2015 (Acres) 2025 (Acres)

Difference (Acres)

Percent Change

High 4773.5 6329.4 1555.9 32.59Medium 1036.8 1061.7 24.9 2.40Low 30074.8 20156.6 -9918.2 -32.98Total Habitat 35885.1 27547.7 -8337.4 -23.23Non-Habitat 456561.7 464899.1 8337.4 1.83Total Land Acres 492446.8 492446.8

Difference (%)Habitat Percent of Total Area 7.3 5.6 -1.7

2015 to 2025 Comparison

Map 1- A comparison of how timber harvest has on Ruffed Grouse habitat between 2015 and 2025.