appendix c-crooked mud honey project deadwood...

Crooked Mud Honey Project Wildlife Report Appendix C DecAID Report

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Appendix C-Crooked Mud Honey Project Deadwood Analysis (DecAid)

Current Direction Based on “Biological Potential”

The goal of management for species richness is to insure that most native wildlife species are

maintained in viable numbers and that habitat requirements for all species must be accounted for

(Thomas, 1979, p.141). Habitat requirements, including snag and down woody material levels,

were described for a vast array of wildlife species using information known at the time in

Thomas (1979) and Brown (1985). However, Bull et al. (1997) states current direction for

providing wildlife habitat on public forest lands does not reflect the new information available,

which suggests that to fully meet the needs of wildlife, additional snags and habitat are required

for foraging, denning, nesting, and roosting. Rose et al. (2001) also state that several major

lessons have been learned in the period 1979 to 1999 that have tested critical assumptions of

earlier management advisory models, including some assumptions used to develop current

recommendations in the LRMP Standards and Guidelines. Some assumptions include:

Calculation of numbers of snags required by woodpeckers based on assessing their

“biological (population) potential” is a flawed technique (Rose et al., 2001). Empirical

studies are suggesting that snag numbers in areas used and selected by some wildlife

species are far higher than those calculated by this technique (Rose et al., 2001).

Numbers and sizes (dbh) of snags used and selected by secondary cavity nesters often

exceed those of primary excavators (Rose et al., 2001).

This suggests the current direction of managing for 100 percent population levels of primary

excavators may not represent the most current knowledge of managing for cavity nesters and that

these snag levels, under certain conditions, may not be adequate for some species.

DecAID is a culmination of the most recent science and data available. As stated by Rose et al.

(2001), DecAID is based on a thorough review of the literature, available research and inventory

data, and expert judgment. Information in DecAID will be compared to the current LRMP

standards and guidelines for this project.

Explanation of the DecAID Version 2.0 Advisory Tool

The snag analysis for the Crooked Mud Honey Project was conducted using DecAID Version

2.0. DecAID is an advisory tool developed to help managers evaluate the effects of forest

conditions (existing conditions or conditions that would result from proposed activities) on

wildlife that use snags and down wood. It is a summary, synthesis, and integration of current

scientific knowledge about the sizes and amounts of snags and down wood used by cavity

nesting birds in specific vegetation types in the West.

DecAID can help managers decide how much snag and down wood of different sizes should be

retained to meet wildlife management objectives for a particular project or area (Mellen et al.,

2006). The information contained in DecAID is based on published scientific literature, research

data, expert judgment, and professional experience. It is primarily a statistical summary of

published research data for wildlife presence (mainly cavity-nesting birds) and inventoried forest

conditions (Mellen et al., 2006). DecAID presents information on the range of “natural


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conditions” (as represented by unharvested plots within the plots sampled), “current conditions”

(all plots sampled, including both unharvested and harvested plots), and wildlife use.

DecAID contains two major data sets, which are summarized by wildlife habitat types. The

vegetative inventory data is composed of statistical summaries of forest inventory data on snags

and down wood in unharvested forests and entire landscapes across Oregon and Washington.

The wildlife data is derived from a thorough review of published literature and other available

data on wildlife use of snags and down wood, primarily in Oregon and Washington. DecAID

provides a statistical synthesis of data showing levels of use by individual wildlife species of

snags and down wood. Wildlife use data are not available for all structural condition classes in

all wildlife habitat types.

Descriptions of terminology and data sources used in DecAID

Two types of data sets provided in DecAID were used to develop recommendations for this

project. They include:

Wildlife data

Vegetative inventory data

Definition of “wildlife data” as used in DecAID:

“Wildlife data” as used in DecAID refers to the data collected in a variety of wildlife studies

conducted in specific vegetation types found in the West. Most of the data was collected for bird

species, primarily cavity-nesters such as woodpeckers. The wildlife data in DecAID is provided

in the form of tolerance levels of 30 percent, 50 percent, or 80 percent. In other words, for a

given study location, data was collected that correlated certain stand conditions (size and

abundance of snags and down wood) with nesting use by 30 percent, 50 percent or 80 percent of

the population of a particular species in that area.

One of these wildlife studies looked specifically at post-fire habitats in the State of Idaho. That

study, which collected data on 35 black-backed woodpecker nests, found that 30 percent of the

nests occurred in stands with less than 62.2 snags >10 inches dbh, per acre. Fifty percent of the

nest sites were found in stands with less than 88.3 snags >10 inches dbh, per acre. Eighty

percent of the nests were located in stands that had up to126.1 snags >10 inches dbh, per acre

(Mellen et al., 2006).

Referring to the array of wildlife data collected, DecAID notes:

“The wildlife studies, on which the wildlife portion of DecAID is based, were conducted in a

variety of landscapes and site conditions. Typically, the studies (a) did not report how the

general study areas and specific study sites were chosen relative to others, and (b) did not

describe how the vegetation conditions within the general study areas and specific study sites

differed from conditions within a broader area, especially within the wildlife habitat and

vegetation condition classes used in DecAID. Thus, there is no way to know to what degree the

study areas and sites varied from conditions generally present, and thus no way to gauge the bias

in study area and site selection. In turn, this means there is no way to estimate the degree of bias

in the wildlife data summarized in DecAID” (Mellen et al., 2006).


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In general, this unknown bias is likely reduced when a greater number and extent of studies are

conducted in a particular wildlife habitat and structural condition. The benefit of the meta-

analysis used in DecAID is that it increases sample sizes, and multiple studies strengthen

evidence of dead wood associations.

Definition of “tolerance level” as used in DecAID for wildlife data:

“Tolerance level” is the percentage of individual birds within a given population that will nest in

forest stands characterized by a certain number and size range of snags. For example, black-

backed woodpeckers show 30 and 50 percent tolerance levels for stands that contain 62 and 88

snags >10 inches dbh per acre, respectively. This means that 20 percent (50 minus 30) of all the

black-backed woodpecker nests in that area were found in stands with snag densities in that

range (tolerance interval).

Data is displayed by tolerance level for both wildlife data and inventory data. A tolerance level

as it relates to wildlife data is defined as follows: “tolerance intervals are estimates of the

percent of all individuals in the population that are within some specified range of values”

(Mellen et al., 2006). For example, we’ll use data from the wildlife species curves for black-

backed woodpeckers.

Snag density (>10inches dbh) for black-backed woodpeckers:

30% tolerance level = 62.2 snags per acre



The above data from 35 nests in post-fire habitats indicate (Mellen, pers.com):

Areas with less than 62.2 snags per acre would be expected to be used for nesting by only

30 percent of the individuals within the population of black-backed woodpeckers, and

conversely 70 percent of the population would be expected to nest in areas with equal to

or greater than 62.2 snags per acre.

Half the individuals within the population would be expected to nest in areas with less

than 88.3 snags per acre and the other half would be expected to nest in areas with equal

to or greater than 88.3 snags per acre.

80 percent of the individuals within the population of black-backed woodpeckers would

be expected to nest in areas with less than 126.1 snags per acre and, conversely, 20

percent of the population would be expected to nest in areas with equal to or greater than

126.1 snags per acre.

Definition of “vegetative inventory data” as used in DecAID:

The second set of data included in DecAID is data about vegetative conditions from around the

Pacific Northwest. This data set is called the “vegetative inventory data,” sometimes shortened

to the “inventory data.” This data set consists of a sample of forest inventory plots (which, in

addition to recording sizes, numbers, and species of live trees, also record sizes and numbers of

snags and down wood), taken from the:


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Current Vegetation Survey (conducted on National Forest System lands in the USDA

Forest Service, Pacific Northwest Region).

Forest Inventory and Analysis (conducted on lands other than National Forest System

lands, by the Pacific Northwest Research Station of the USDA Forest Service).

Natural Resource Inventory (conducted by the USDI Bureau of Land Management on

BLM lands in Oregon) (Mellen et al., 2006).

The vegetative inventory data set summarizes the data from these various inventory plots in

various categories, such as:

The data from only those inventory plots that have not been harvested.

The data from all inventory plots in their current condition, including those that have

been harvested.

The data from only those inventory plots that contained measurable snags.

The data from all inventory plots, whether or not they contained measurable snags.

A map of the plot locations (both harvested and unharvested) used in DecAID can be found on

the following website: http://www.notes.fs.fed.us:81/pnw/DecAID/DecAID.nsf.

Definition of “tolerance level” as used in DecAID for vegetative inventory data

DecAID also uses the term “tolerance level” with respect to the dead wood conditions measured

in the vegetative inventory data set. However, “tolerance level” has a different definition when

used in conjunction with the vegetative inventory data set. In this context, tolerance levels

describe the sizes and amounts of dead wood found to be characteristic across the landscape (that

is, the area represented by the sampled plots), for a certain vegetative type (for example,

ponderosa pine) in a certain condition (for example, unharvested) (Mellen et al., 2006). To more

fully illustrate this definition, the following example, extracted from DecAID, is offered:

For the category: vegetative type, Ponderosa Pine/Douglas-fir Forest, Larger Trees, in the

condition, Unharvested and contains measurable snags, a tolerance level of 80 percent with

respect to snags indicates that 80 percent of the acres in this category are expected to have fewer

than 13.3 snags per acre (10 inches dbh or larger) and 20 percent of the acres are expected to

have more than 13.3 snags per acre (10 inches dbh or larger). In other words, for all the acres

sampled in the large ponderosa pine/Douglas fir category that have never been harvested and that

contain some amount of snags, 80 percent of the time these acres should have fewer than 13

snags (10 inches dbh or larger).

It is important to remember that these data represent average snag numbers for a particular

vegetative type and condition at a regional level, rather than vegetative conditions and snag

numbers specific to nest sites. When considering this data, wildlife managers need to adjust it in

light of the vegetation conditions present in their local project area.

Crooked Mud Honey EA Vegetation Distribution Information

http://www.notes.fs.fed.us:81/pnw/DecAID/DecAID.nsf


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The Silviculturist on the interdisciplinary team determined the percentages of the forested areas

in the watershed as displayed in Table 1.

Table 1: Vegetation types of Forest Service land within the Crooked Mud Honey (CMH) project area by acres and percent of project area.

Vegetation Type Approximate Acres Approximate Percentage

of the Subsheds

Juniper Steppe 2,417 5%

Juniper Woodlands 523 .5%

Dry Lodgepole Pine 23 .5%

Ponderosa Pine-Lodgepole

Pine

1,722 4%

Dry Ponderosa Pine 3,497 8%

Xeric Pine 3,887 8%

Dry White Fir 16,459 35%

Moist White Fir 635 1%

Wet White Fir 63 .5%

Cold Dry White Fir 15,913 34%

Dry Whitebark Pine 1,316 3%

Wet Lodgepole Pine 28 .5%

Total 46,483 100

The Sivliculturist also determined vegetation seral stages for both reference and current

conditions in Table 2 below from historical data and current conditions. The juniper vegetation

type will not be addressed related to snags or down wood.

Table 2: Current seral and structural stage for closed canopy plant associations in CMH project area compared to reference conditions in percent.

Reference

Condition

Current

Condition

Historical

CMH project

area

Early Seral Closed

Canopy

Dry Lodgepole Pine, Pole Stage 5- 40 86

Moist White Fir, Small Tree Stage 3-8 25

Cold Dry White Fir, Small Tree Stage 0-8 37

Mid Seral Closed

Canopy

Ponderosa Pine-Lodgepole Pine, Small Tree

Stage 1-8 25

Late Seral Closed

Canopy

Juniper Steppe, Large Tree Stage 0 19

Juniper Woodlands, Small Tree Stage 15-30 65


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Ponderosa Pine-Lodgepole Pine, Large Tree

Stage 1-4 31

Dry Ponderosa Pine, Small Tree Stage 0-4 32

Dry Ponderosa Pine, Large Tree Stage 0-4 35

Cold Dry White fir, Large Tree Stage 4-8 18

Table 3: Current seral and structural stage for open canopy plant associations in CMH Project area compared to reference conditions in percent.

Reference

Condition

Current

Condition

Viable Code Historical

CMH project

area

Early Seral Open

Canopy

Juniper Woodlands, Grass-Forb-Shrub Stage 50-70 3

Late Seral Open Canopy

Wet White Fir, Small Tree Stage 0-2 46

Dry Ponderosa Pine, Large Tree Stage 15-33 0

The amount of closed canopy stand conditions have increased due to past management activity

and lack of frequent fire. As displayed in Table 2, the amount of late seral closed canopy juniper

PAGs is well over represented within CMH. The amount of dry ponderosa pine both small and

large tree structures are also well over-represented in terms of late seral, closed canopy stands.

Table 3 displays early and late seral stand conditions that are open canopy. Currently, only 3

percent of juniper woodlands are in an open canopy condition when historically this stand

condition was represented 50 to 70 percent across this PAG. The dry ponderosa pine, late seral,

open canopy stand type is currently at 0 percent compared to historic reference conditions of 15

to 33 percent.

Use of DecAID Inventory Data

It is important to recognize that the vegetative inventory data for unharvested plots represents

vegetation conditions (including presence and abundance of snags and down wood) measured at

a single point in time. Yet these conditions reflect events (such as fire, or the suppression of fire)

that have occurred over a span of time, potentially anywhere from decades to centuries (Mellen

et al., 2006). For this reason, Johnson and O’Neil (2001) recommend that caution be exercised

in using DecAID’s vegetative inventory data to describe the estimated historical range of

conditions with respect to dead wood, because the vegetative inventory data is only a sample of

current conditions and lacks information about site history.

The abundance of snags and down wood has been altered to an unknown degree by fire

suppression and other human influences. On the east side of the Cascades in particular, current

levels of snags and down wood in some areas may be higher than historically existed, because of

successful fire suppression and increases in mortality due to the development of overly dense

stands. Other areas on the eastside may exhibit snag and down wood numbers lower than


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historic levels because snags/down wood were consumed in severe fires or removed by repeated

harvest and firewood cutting (Johnson and O’Neil, 2001).

The terms Historic Range of Variability (HRV), Natural Conditions, and Historical Conditions

are sometimes used interchangeably to indicate conditions which occurred on the landscape prior

to the influence of humans (particularly Europeans). Because it is difficult to determine what

snag and down wood levels were prior to influence of humans, the term reference condition is

used in this document in reference to the use of inventory data from DecAID. While it is not

known how well the data represents pre-European levels, the data do provide a reference

condition for managers to consider.

Caution should be used when assuming unharvested stands represent “natural” or reference

conditions. Due to years of fire exclusion, current levels and composition of snags and down

wood may not accurately reflect “pre-settlement” or reference conditions in eastside forests

(Mellen et al., 2006). Although current snag and down wood levels found in DecAID may not

accurately reflect reference conditions, they are still within reason when compared to other

current research as described below. Refer to the document “Comparison of Historical Range of

Variability for Dead Wood: DecAID vs. Other Published Estimates”

(http://www.fs.fed.us/r6/nr/wildlife/decaid/hrv-dead-wood-comparison.shtml) for more

information. DecAID vegetation data provide the most current scientific data available and it is

the only data that indicates the historical distribution of snag densities.

How the Data in DecAID was Reviewed Specific to This Project

Methodology: Existing snag conditions were derived using Gradient Nearest Neighbor, or GNN;

Ohmann and Gregory 2002. Refer to the website www.fsl.orst.edu/lemma for more information

on the GNN data. This analysis is intended to be a course level analysis of snag density and

distribution within the CMH Project area.

Assumptions

1.) The reference condition in DecAID represents historical range of variability.

2.) The GNN data is representative of existing snag densities.

3.) The snag analysis area includes 12 Subwatersheds within the CMH Project area.

The CMH project will be evaluated for snag habitat with this method: 1) a distribution analysis,

inventory level analysis, and wildlife tolerance level analysis.

1. Distribution analysis

The vegetation inventory data in DecAID from the unharvested portion of the landscape can be

used as a reference or desired future conditions; it is a coarse-filter approach to management at a

broad landscape scale. As a general rule-of-thumb, it is suggested that planning areas be at least

20 square miles in size [12,800 acres]. DecAID states that analysis areas (landscapes or

watersheds) should be sufficiently large to encompass the range of variation in wildlife habitat

types and structural conditions that occur in the area (Mellen et al., 2006). The CMH project

area is 51,525 acres. Four Decaid wildlife habitat types are found within the project area. The

dominate type Eastside Mixed Conifer (EMC) Forest habitat type includes 40,949 acres,

http://www.fs.fed.us/r6/nr/wildlife/decaid/hrv-dead-wood-comparison.shtml

http://www.fsl.orst.edu/lemma


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Lodgepole Pine Forest (LP) habitat type 72 acres, Montane Mixed Conifer Forest (MMC) 1,180

acres, and Ponderosa Pine/Douglas-fir Forest (PPDF) 3,386 acres. Because acreage totals were

so small all four habitat types were combined and then analyzed using the EMC forest habitat.

After combining habitat types the total EMC habitat type within the CMH project area was

46,483 acres. The CMH project area is within the Upper and Lower Camas Creek, Middle

Thomas Creek, Lower Cox Creek, Upper and Lower Crooked Creek, Upper and Lower Drake

Creek, Upper and Lower Honey Creek, McDowell Creek and Mud Creek Subwatersheds and,

therefore, it is appropriate to make a comparison to the vegetation inventory data in DecAID.

DecAID was used to compare existing condition to reference conditions for the effects analysis

of this project. The reference of snag and down wood distribution represented by the summary

of forest inventory data from unharvested inventory data in DecAID will be compared with the

project alternatives. It is assumed that, if snag numbers and distribution are similar to reference

conditions, the snag needs of cavity nesting birds would be met within the historic range of

variability.

Eastside Mixed Conifer Powell suggests the following stand structure types as a reference condition (2010):

Table 4: Reference Conditions for the Percentage of the Landscape in the Each Habitat Type

EMC_EBC_Open 50%

EMC_EBC_Small/Medium 15%

EMC_EBC_Large 35%

The following steps were taken in order to compare reference conditions from the vegetative

inventory data in DecAID to existing condition.

Snags Greater Than 10 Inches dbh - Distribution

Table 5: The distribution histograms from unharvested plots in DecAID shown in Table 5 (figures EMC_ECB_O.inv-14, EMC_ECB_S.inv-14, and EMC_ECB_L.inv14) were referenced to determine the percentage of the landscape in each of the snag density categories for snags >10” dbh.

Habitat

Type/

Structure

Stage

0

Snags/acre

>10” dbh

0-6

Snags/acre

>10” dbh

6-12

Snags/acre

>10” dbh

12-18

Snags/acre

>10” dbh

18+

Snags/acre

>10” dbh

EMC_ECB_O 29% 30% 16% 6% 20%

EMC_ECB_S 15% 25% 17% 18% 26%

EMC_ECB_L 22% 32% 15% 12% 19%

Table 6: The percentage of the landscape in each snag density category for the EMC_ECB_O, EMC_ECB_S, and EMC_ECB_L categories (snags >10 inches dbh) were weighted to match the estimated historical range of variability for the CMH Project Area

Habitat

Type/

Structure Stage

Historic

Range Of

Variability

Percent in

Structure

Weighted

Average of

Percent of

Landscape

with 0

Weighted

Average of

Percent of

Landscape

with 0-6

Weighted

Average of

Percent of

Landscape

with 6-12

Weighted

Average of

Percent of

Landscape

with 12-18

Weighted

Average of

Percent of

Landscape

with >18


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Stage Snags/acre

>10” dbh

Snags/acre

>10” dbh

Snags/acre

>10” dbh

Snags/acre

>10” dbh

Snags/acre

>10” dbh

EMC_ECB_O 50% (29*.5)

14.5

(30*.5)

15.0

(16*.5)

8.0

(6*.5)

3.0

(20*.5)

10

EMC_ECB_S 15% (15*.15)

2.25

(25*.15)

3.75

(17*.15)

2.55

(18*.15)

2.7

(26*.15)

3.9

EMC_ECB_L 35% (22*.35)

7.7

(32*.35)

11.2

(15*.35)

5.25

(12*.35)

4.2

(19*.35)

6.65

Table 7: The total percent of the landscape in each snag density category for snags per acre >10 inches dbh based on the inventory data from DecAID for EMC_ECB Type for the EMC_ECB_S, EMC_ECB_O, and EMC_ECB_L combined

0

Snags/acre

>10” dbh

Total

Percent of

Landscape

with

0-6

Snags/acre

>10” dbh

Total

Percent of

Landscape

with

6-12

Snags/acre

>10” dbh

Total

Percent of

Landscape

with

12-18

Snags/acre

>10” dbh

Total

Percent of

Landscape

with

>18

Snags/acre

>10” dbh

24% 30% 16% 10% 21%

Table 8: The Existing Condition for Snags >10”dbh Based on GNN Data

Total

Percent of

Landscape

with

0

Snags/acre

>10” dbh

Total

Percent of

Landscape

with

0-6

Snags/acre

>10” dbh

Total Percent of

Landscape with

6-12

Snags/acre

>10” dbh

Total

Percent of

Landscape

with

12-18

Snags/acre

>10” dbh

Total Percent of

Landscape with

>18

Snags/acre

>10” dbh

33% 34% 12% 3% 18%


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Figure 1: Existing Condition for Snag Densities Greater Than 10 Inches dbh Compared to the Reference

Conditions in Decaid.

3334

12

3

18

24

30

16

10

21

0

5

10

15

20

25

30

35

40

0 0-6 6-12 12-18 18+

Pe

rce

nt

of

Lan

dsc

ape

Snags per acre

Existing Condition for Snag Densities Greater Than 10 Inches dbh Compared to the Reference Conditions in

DecAID

Current Condition

Reference Condition

Total Snags Greater Than 20 Inches dbh - Distribution

Table 9: The distribution histograms from unharvested plots in DecAID (figures EMC_ECB_O.inv-15, EMC_ECB_S.inv-15, and EMC_ECB_L.inv15) were referenced to determine the percentage of the landscape in each of the snag density categories for snags >20” dbh.

Habitat

Type/

Structure

Stage

0

Snags/acre

>10” dbh

0-2

Snags/acre

>10” dbh

2-4

Snags/acre

>10” dbh

4-6

Snags/acre

>10” dbh

6+

Snags/acre

>10” dbh

EMC_ECB_O 53% 22% 10% 5% 10%

EMC_ECB_S 31% 18% 17% 13% 21%

EMC_ECB_L 32% 8% 19% 14% 27%

Table 10: The percentage of the landscape in each snag density category for the EMC_ECB_O, EMC_ECB_S, and EMC_ECB _L categories (snags >20 inches dbh) were weighted to match the estimated historical range of variability for the Crooked Mud Honey Project Area

Habitat

Type/

Structure Stage

Historic

Range Of

Variability

Percent in

Structure

Stage

Weighted

Average of

Percent of

Landscape

with 0

Snags/acre

>10” dbh

Weighted

Average of

Percent of

Landscape

with 0-2

Snags/acre

>10” dbh

Weighted

Average of

Percent of

Landscape

with 2-4

Snags/acre

>10” dbh

Weighted

Average of

Percent of

Landscape

with 4-6

Snags/acre

>10” dbh

Weighted

Average of

Percent of

Landscape

with >6

Snags/acre

>10” dbh

EMC_ECB_O 50% (53*.5)

26.5

(22*.5)

11.0

(10*.5)

5.0

(5*.5)

2.5

(10*.5)

5.0

EMC_ECB_SM 15% (31*.15)

4.65

(18*.15)

2.7

(17*.15)

2.55

(13*.15)

1.95

(21*.15)

3.15

EMC_ECB_L 35% (32*.35)

11.2

(8*.35)

2.8

(19*.35)

6.65

(14*.35)

4.9

(27*.35)

9.45


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Table 11: The total percent of the landscape in each snag density category for snags per acre >20 inches dbh based on the inventory data from DecAID for EMC_ECB Type for the EMC_ECB_S, EMC_ECB_O, and EMC_ECB_L combined

Total

Percent of

Landscape

with

0

Snags/acre

>10” dbh

Total

Percent of

Landscape

with

0-2

Snags/acre

>20” dbh

Total

Percent of

Landscape

with

2-4

Snags/acre

>20” dbh

Total

Percent of

Landscape

with

4-6

Snags/acre

>20” dbh

Total

Percent of

Landscape

with

>6

Snags/acre

>20” dbh

42% 17% 14% 9% 8%

Table 12: The Existing Condition for Snags >20”dbh Based on GNN Data

Total

Percent of

Landscape

with

0

Snags/acre

>20” dbh

Total

Percent of

Landscape

with

0-2

Snags/acre

>20” dbh

Total

Percent of

Landscape

with

2-4

Snags/acre

>20” dbh

Total

Percent of

Landscape

with

4-6

Snags/acre

>20” dbh

Total

Percent of

Landscape

with

>6

Snags/acre

>20” dbh

46% 26% 5% 13% 10%

Figure 2: Existing Condition for snag Densities Greater Than 20 Inches dbh Compared to the Reference

Conditions in Decaid

GNN Data


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Table 13 below displays snag information contained in the Gradient Nearest Neighbor data set.

GNN contains data averaged over many stand types and conditions. The larger the scale that this

data is used, the more accurate it becomes for particular vegetation type. This data indicates that

we exceed Forest Plan standards related to snag densities.

Table 13: GNN snag data for the Fremont-Winema National Forest by EMC vegetation type

Number of Snags EMC Snags per Acre

> 12 cm (4.7 in.) DBH 18.3

> 25 cm (9.8 in.) DBH 6.6

> 50 cm (19.7 in.) DBH 1.5

DecAID Snag Diameter Information

Table 14 below displays the average snag diameter used by cavity excavator species by tolerance

level and forest habitat type taken from DecAID. Generally speaking higher tolerance levels

provide for a greater percentage of the individuals within a population.

Table 14: Snag diameter information by tolerance levels for selected wildlife species from DecAID Tables EMC_L.sp-17, EMC_S.sp-17.

Forest Wildlife Habitat Type EMC Mixed Conifer

Species

30% t.l.

snag

DBH (in)

50% t.l.

snag

DBH (in)

80% t.l.

snag

DBH (in)

BBWP-Black-backed Woodpecker 8.8 12.0 16.7

HAWO-Hairy Woodpecker 10.5 16.3 25.2

NOFL-Northern Flicker 17.7 22.2 30.6

PCE-Primary Cavity Excavators 16.8 23.1 33.3

PIWO-Pileated Woodpecker 25.2 29.5 36.0

WHWO-White-headed Woodpecker 20.8 26.7 35.9

WISA-Williamson’s Sapsucker 20.2 26.2 34.6

Data Source within DecAID Table EMC_L.sp-17 and

EMC_S.sp-17. (numbers in these tables are the same)

When Table 14 above is compared with Tables 5-12 above and Figures 1-2, it shows that the

project area is providing snag diameters that could be used by these wildlife species. Generally

speaking higher tolerance levels provide for a greater percentage of the individuals within a

population.

Snag Density Information

Densities of snags are also important for determining level of habitat provided. Table 15 below

was compiled with information from DecAID (version 2.0) Tables EMC_S/L.sp-22. This table

contains synthesized data for wildlife use of snag densities from various studies for the Eastside

Mixed Forest Conifer Wildlife Habitat Type and Small/medium Trees and Larger Trees

Structural Condition Classes.

Interpreting Table 15 below indicates for the four cavity excavator species with data available

generally shows that increasing the snag diameter reduces the number of snags per acre needed

to accommodate the same percentage of the population.


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13

Table 15: Synthesized snag density information by tolerance levels for selected wildlife species from DecAID Tables EMC_S/L.sp-22.

Snag Size >= 6.4” dbh Snag Size >= 9.6” dbh Snag Size >= 20” dbh

Species

30% t.l.

snag

density

(#/ac.)

50% t.l.

snag

density

(#/ac.)

80% t.l.

snag

density

(#/ac.)

30% t.l.

snag

density

(#/ac.)

50% t.l.

snag

density

(#/ac.)

80% t.l.

snag

density

(#/ac.)

30% t.l.

snag

density

(#/ac.)

50% t.l.

snag

density

(#/ac.)

80% t.l.

snag

density

(#/ac.)

BBWP-Black-backed

Woodpecker

no data no data no data 2.5 13.6 29.2 0 1.4 5.7

PIWO-Pileated

Woodpecker

no data no data no data 14.9 30.1 49.3 3.5 7.8 18.4

WHWO-White-

headed Woodpecker

Table EMC_S/L.sp-22

only

0.8 3.0 6.2 0.3 1.9 4.3 0 1.5 3.8

WISA-Williamson’s

Sapsucker

no data no data no data 14.0 28.4 49.7 3.3 8.6 16.6

In summary, snag densities were compared with Figures 1-2. The following species are

currently being provided for at the tolerance levels indicated. The CMH project area has pockets

of bug kill including 1377 acres of lodgepole that will be retained on the landscape. Retention

areas, no cut areas, single tree retention areas will also provide smaller dbh conifers in dense

patches required by species above.


Wildlife

14

Snag Summary for CMH Project Area Harvest prescriptions within the CMH project area call for thinning from below, variable density

spacing, and skip/gap techniques. These prescriptions will be followed with prescribed fire. The

effect of this on these stands is that there will be a mosaic of stand densities across the landscape,

and these stands would be within the historical range of variability, and therefore, should

continue to allow the natural processes that create snags to function. Also, the design criteria to

retain 15-20% of each treatment unit will leave areas of these stands above the insect threshold.

Additionally, no treatment areas will be dispersed across the CMH project area. Ponderosa pine

trees >21” will also not be harvested within the project area. Within the Eastside mixed conifer

vegetation community there has been a shift from the larger tree structural stage to small/medium

structural stages. This shift is the result from past harvest practices, and fire suppression. In

areas of past clear cuts and salvage logging, snag density is likely less than what would have

occurred historically.

The overall affect is that without recent snag survey data, it is difficult to quantify statistically

what is there right now. However, it appears based on GNN data snag information available that

the project area is close to reference conditions and Forest Plan standards (white paper from the

Forest identifying 4 snags/acre). Past logging practices and fire suppression have moved current

conditions above/below reference conditions in some categories. The proposed action and time

will move current conditions back toward historic snag reference conditions.

Down Wood Summary CMH Project Area

Definition of “down wood percent cover”, as used in DecAID:

DecAID includes data on down wood, a habitat component used by many wildlife species.

DecAID uses “down wood percent cover” to measure the presence of down wood on a given

acre. “Down wood percent cover” means within a given area, the percentage of the ground that

is covered with down wood at least 4.9 inches dbh on the small end and at least 3.3 feet long.

Wood in any decay class is included in the measurement as long as it meets the size criteria.

This way of measuring down wood was used in DecAID because it best describes the abundance

of down wood as it relates to wildlife use (Mellen et al., 2006). “Down wood percent cover” is

one of the most precise and efficient means of recording amounts of down wood, and is the

measure most commonly used in research studies that investigate wildlife use of down wood. As

an illustration of how this measure is applied, one acre exhibiting 0.9 percent down wood cover

might contain:

One 30-inch dbh ponderosa pine down tree 100-feet long

One 20-inch dbh ponderosa pine down tree 80-feet long

One 15-inch dbh ponderosa pine down trees 60-feet long

Two 10-inch dbh ponderosa pine down trees 40-feet long

or, that same acre could also exhibit 0.9 percent down wood cover with one of the groups below:

4.0 - 20-inch dbh ponderosa pine down trees 80-feet long OR

6.7 - 15-inch dbh ponderosa pine down trees 60-feet long OR

16.7 - 10-inch dbh ponderosa pine down trees 40-feet long.


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DecAID provides information on American marten, the woodpeckers as a group and ants upon

which several species forage. The following table is information from DecAID Table

EMC_L.sp-21. This table is the result of synthesized data for wildlife use of down wood sizes

(diameter) for denning, resting, ant colonies, foraging and occupied sites from studies for the

various habitat types.

Table 16: Synthesized Data For Wildlife Use of Down Wood Sizes From Various Studies By Forest Type, Small and Large Structure Size and Tolerance Level From DecAID.

Habitat Type EMC Mixed Conifer

Species

30% t.l.

Down Wood

Dia. (in)

50% t.l.

Down Wood

Dia. (in)

80% t.l.

Down Wood

Dia. (in)

AMMA-American Marten 20.7 26.1 33.2

LANT-Large ant species 7.4 10.3 14.8

SANT-Small ant species 7.5 10.3 14.6

WOPE-Wood peckers 8.0 11.2 16.0

The last piece of information needed to evaluate the habitat is the density of down wood. Again

DecAID is used to describe habitat needs of species for which information is available. Table 17

information below is from DecAID table EMC_S/L.sp-24.

Table 17: Synthesized Data For Wildlife Use of Down Wood Densities From Various Studies By Forest Type, Small and Large Structure Size and Tolerance Level From DecAID.

Habitat Type EMC Mixed Conifer (> 5.9” Dia.)

Species 30 %t.l.

Down Wood

Cover (%)

30 %t.l.

Down Wood

Cover (%)

30 %t.l.

Down Wood

Cover (%)

BBWO-Black-backed

woodpecker

4.7 13.0 25.1

PIPO-Pileated woodpecker 4.0 4.5 5.1

Down Wood Summary for the Proposed Project Area

Due to a lack of quantifiable data, it is not known how much down wood is present within the

CMH project area, and therefore, unknown what tolerance levels are being provided for. Areas

of past clear cuts, salvage and overstory removal are likely not providing much down wood;

however, due to fire exclusion and limited prescribed burning, much of the area should be

providing down wood levels towards the upper end or above what has occurred historically.

While data was not available for down wood percent cover and wildlife use, other projects on

this Forest have looked at the vegetation inventory information for down wood percent cover,

and it appears within the Eastside mixed conifer stands it appears to be on the high side of what

would have been on the ground historically with a frequent fire return interval. Most likely this is

from high densities of conifer per acre and fire suppression. Also historically, it is likely that the

higher density areas of down wood were part of the shifting mosaic across the landscape that

resulted from insects or fire killing small patches of trees.

The Crooked Mud Honey project will not specifically target snags for removal. The overall

project design is to reduce the density of understory green trees on National Forest lands.

Hazard trees alongside roads and landings (likely within 100 feet) could be removed; however,


Wildlife

16

hazard trees that are felled in the interior of units would be retained to contribute to down wood,

and decrease the incentive to cut them.

The requirement to maintain felled hazard trees inside of units as down wood would help assure

that it is being provided for across the landscape. However, by re-introducing fire into these

stands, some of this would be consumed. As prescribed fire use is continued over time, the area

would be expected to provide down wood consistent with HRV levels, and also at levels

consistent with what the stand is capable of providing.

Continuation of Ecological Processes

The Silviculturist identified that many of the open stands are mainly past clear cuts, a technique

which the Forest does not currently practice. Past clear cuts that were reforested are moving

towards the small/medium structural stage, these stands will thin and in 10-20 years should

provide snags and down wood. Areas that were historically more open habitats are becoming

closed canopy. This is reducing vegetation diversity across the landscape. Removing

encroachment conifer will move sage steppe, meadows , mahogany stands and aspen habitats

back to historical conditions.

The CMH project is retaining existing snags (except hazard trees), and future snags are being

provided for by retention of stocked stands, 15-20% of each unit will be retained, and not

treating approximately 5,986 acres within the project boundary.

The CMH project is retaining existing down wood, and future down wood is being provided for

by retention of existing snags, and maintaining tree stocking levels within or at the high end of

the historical range of variability.

It is assumed that if snag numbers and distribution and down wood size and distribution are

similar to “natural” conditions, that we would be meeting the snag needs of cavity nesting birds

under the historic range of variability. Areas of past management activities (past harvest) are

likely deficient in snags. Therefore, stands that are currently stocked with commercial size trees

would likely be needed to meet snag dependent species requirements across the subsheds. This

is consistent with the proposed projects requirements to retain existing snags except where they

pose a safety issue.

References

Brown, James K., Elizabeth D. Reinhardt, and Kylie A. Kramer. 2003. Coarse woody debris:

Managing benefits and fire hazard in the recovering forest. Gen. Tech. Rep. RMRS_GTR-105.

Ogden UT. USDA, Forest Service, Rocky Mountain Research Station. 16p.

http://www.fs.fed.us/rm/pubs/rmrs_gtr105.pdf

Bull, Evelyn L., Catherine G. Parks, and Torolf R. Torgersen. 1997. Trees and Logs Important to

Wildlife in the Interior Columbia River Basin. Gen. Tech. Rep. PNW-GTR-391. Portland, OR:

U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 55p.

Mellen, Kim, Bruce G Marcot, Janet L. Ohmann, Karen L. Waddell, Elizabeth A. Willhite,

Bruce B. Hostetler, Susan A. Livingston, Catherine Ogden, and Tina Dreisbach. 2006. The

http://www.fs.fed.us/rm/pubs/rmrs_gtr105.pdf


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DecAID repository: background information for DecAID, the decayed wood advisor for

managing snags, partially dead trees, and down wood for biodiversity in forests of Washington

and Oregon. USDA Forest Service, Pacific Northwest Research Station and Pacific Northwest

Region, Portland, Oregon. Available on-line at:

http://wwwnotes.fs.fed.us:81/pnw/DecAID/DecAID.nsf.

Powell, David C. 2010. Range of Variation Recommendations for Dry, Moist, and Cold Forests.

White Paper F14-SO-WP-SILV-3. Umatilla National Forest. Supervisor's Office, Pendleton,

OR

Thomas, Jack Ward. September, 1979. Wildlife Habitats in Managed Forests, the Blue

Mountains of Oregon and Washington. U.S.D.A. Agriculture Handbook No. 553. 512 pp.

http://wwwnotes.fs.fed.us:81/pnw/DecAID/DecAID.nsf

appendix c-crooked mud honey project deadwood...

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