habitat conditions and targets

Habitat Conditions and Targets

How did we get here?

Overview

What is a condition? What is a target? Fisher data used Characterizing

conditions Target estimation Example Operational

application Summarize process

Conditions and Targets

Provide forestry personnel with an idea of:• What good fisher

habitat looks like • How much of it is

needed by fishersUsed to provide guidance to help make operational decisions in fisher habitat

Habitat Relationships Across BC

Forest composition varies considerably across regions Species composition Tree growth and decay Understory diversity

and cover Desired Habitat

Conditions and Targets vary too

What do fishers need?

1. Collect information on fishers Capture, radiotag and monitor fishers to:

1. Identify the structures used by fishers for rearing offspring and resting.

2. Identify the stands used by fishers for rearing, resting, foraging, and movement.

3. Determine the size and composition of the home range of each tagged fisher.

What do fishers need?

1. Collect information on fishers

2. Measure habitats used by fishers a) Characterize the

MINIMUM STRUCTURAL ATTRIBUTES of rearing and resting sites

b) Characterize HIGH-QUALITY STAND ATTRIBUTES of stands used by fishers [VRI]

At as leading speciesQ_DIAM_125=24.4 cmPROJ_AGE_1=128PROJ_HT_1=27.1

How much do fishers need?

1. Collect information on fishers

2. Measure habitats used by fishers

3. Estimate targetsa) Estimate the MINIMUM DENSITY of “high-quality stands” needed for each behaviour within each home range

b) Estimate the TOTAL NUMBER OF STRUCTURES that need to occur within the home range.

18.9% of homerange in “high-quality” den stands

Say What?

• Minimum Structural Attributes??

• High-Quality Stand Attributes??

• Minimum Stand Density??

• Total Number of Structures??

MINIMUM STRUCTURAL ATTRIBUTES

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Why 75%?

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mean:47.6 cmSD: 14 cm

Why 75%?

75% of rest sites were >39.5 cm

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Why 75%?

Bigger actually is better

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75%

100%

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Prob

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HIGH-QUALITY STAND ATTRIBUTES

MINIMUM STAND DENSITY

TOTAL NUMBER OF STRUCTURES

Desir

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This process allows us to:1. Identify the minimum characteristics of

trees used by fishers for rearing and resting.

2. Identify high- and low-quality stands for each activity.

3. Identify the minimum density of “high-quality” stands that support fishers.

4. Estimate the total number of structures¹ that fishers need within home ranges.

¹ that meet minimum criteria of (1)

Summary

A Few Important Notes

Not all trees that meet the minimum criteria are suitable

Things we can measure vs. things fishers need

TOTAL NUMBER OF STRUCTURES is based on the things we can measure

Refining the minimum criteria to better reflect what fishers need would refine the target.

1

A Few Important Notes

Males don’t really matter! Female fishers are the real habitat

specialists• Have to find enough structures and

habitats to support themselves in a smaller area than males

Males simply go wherever the girls are…and pick up food along the way

Conditions and targets that we present are derived from data on female fishers

2

How would they get used?Conditions and Targets

Applying Targets

HUH??5,250 aspen trees >40 cm dbh and 2,620 balsam poplar trees >54 cm dbh in a 30 km² area?

Targets for each harvest unit depend upon features of:1. LANDSCAPE: Density of high-quality stands

[above or below minimum requirement]2. STAND: relative quality of the stands

[high- or low-quality for each activity]3. SUB-STAND: Timber cruise or site-plan

ground data[density of minimum structural attributes or other features]

What are the Targets?

Targets - Landscape Assessment

MINIMUM STAND DENSITY

Information needed:1. Identify stands with

“High-Quality Stand Attributes”• QUERY VRI

2. Determine where the density of high-quality stands is greater than the “Minimum Stand Density”• SPATIAL ANALYSIS

Allows licencee to determine if proposed block is in an area with sufficient density of stands.

HIGH-QUALITY STAND ATTRIBUTES

Targets - Stand AssessmentHIGH-QUALITY STAND ATTRIBUTESMINIMUM STRUCTURAL ATTRIBUTES

Information needed:1. Determine if unit is in a

“High-quality stand”• VRI QUERY

2. Determine if this stand is rare in the surrounding landscape• LANDSCAPE

ASSESSMENT3. Estimate density of

structures that meet minimum structural attributes• CRUISE OR SITE PLAN

DATA

Decisions, decisions…

Landscape AboveMinimum Stand Density

BelowMinimum Stand Density

Meet High-quality Stand AttributesStand

Sub-Stand

Not Meet High-quality Stand Attributes

Trees with MinimumStructural Attributes Abundant

Trees with MinimumStructural Attributes Rare

Assessments and Targets

The results of the landscape and stand assessment helps guide targets for the unit Rearing Resting Foraging MovementLikely considerable overlap Meet multiple targets with

single prescription