Forest Plot Monitoring on the Niagara Escarpment : A Discussion of Trends as a Tool for Assessing Natural Heritage Protection

Robert Milne Wilfrid Laurier University

Anne Marie Laurence Niagara Escarpment Commission

Lisa Grbinicek Niagara Escarpment Commission

Lorne Bennett University of Guelph

Presentation Overview

•

Overview of the Forest Health Monitoring Program

•

Background of forest dynamics –

Niagara Escarpment

•

Results of Forest Plot Monitoring▫

Dynamics

▫

Changes to Forest Structure▫

Health and Invasives

•

Discussion and Recommendations for Management

Forest Monitoring Program

•

ONE monitoring program –

NEC•

Monitor changes in forest structure, dynamics and health

•

Detect threats to core biosphere integrity▫

Disease

▫

Invasive▫

Climate change

▫

Human impact•

Program Assessment –

efficiency of NEC

policies, decisions and practices

Why Monitor?•

Assess efficiency of management

•

Continuity –

not found in short-term research

•

Baseline to measure human and natural change

•

Understand long-term dynamics and patterns of biodiversity

•

Educational component

Plots•

Escarpment Natural Area designation

•

public lands within the NEPA –

long-term

use•

upland deciduous interior forest ▫

intermediate to mature

▫

disturbance is minimal

•

accessible via trails

•

complementary monitoring programs

Methods•

Monitor 1ha plot

•

five year cycle -

15 years

•

Partners -

NEC, UW•

Tree species and status▫

Basal area

▫

Density▫

Frequency

•

Crown class•

Health –

yearly

Hockley Valley Provincial Nature Reserve Plot

Forest Dynamics - Escarpment•

Gap dynamics

•

Disturbance▫

Geomorphic processes

▫

Environmental Stress

stone channel

debris slide

toppling

karst

freeze-thaw/talus accumulation

bench

soil creep/sheetwash

freeze-thaw/talus accumulation

blockfall

Type A: cliff face

Type B: buried face

Type C: rounded face

A

Debris Slide

B Blockfall

C Single Tree

Replacement

Blockfall – Skinner’s Bluff

Mass Wasting Processes

C

BA

Richness and Abundance

•

Highest richness –

Halton –

ecotonal forest

•

Similar values in northern forests

•

Abundance not related to geographic position –

disturbance regime•

General pattern of decrease in abundance –

maturing forests

Richness and Abundance

Halton

Hope Bay

Abundance and Importance•

Declining abundance –for most plots

•

Some loss of shade-

intolerant –

including

smaller sugar maple•

Compare with Importance Value▫

Frequency, Dominance and Abundance

•

Importance value showed relative stability of sites

Stem Diameter

•

All plots had increase in stem size

•

Range from 0.7% to 8.2%

•

Pattern of increasing size over time reflects maturing of forests

10‐19.9 20‐29.9 30‐39.9 40‐49.9 50‐59.0 60+0

50

100

150

200

250

300

350

400

450

Numbe

r of stems

dbh (cm) 

Diameter‐at‐breast (dbh) Size Distributionin the Halton Regional Forest plot

1996

2001

2006

Disturbance – Human Activity

•

Reflect impacts of disturbance▫

Selective logging

▫

Fire

▫

Grazing

•

Even-aged stand

•

Absence of younger tree

Tree Health•

Standards Canadian Forest Service –

healthy

▫

Crown vigour

▫

Mortality Rate

•

No record >25% dieback

•

Proportion severe decline <4% at most

•

Mortality rates ranged 1.8 to 2.9%

Forest Change•

Patterns -

seedling

to sapling•

Most plots -

canopy trees represented in understory

•

Consider disturbance and competition

•

Early warning of impacts and change

•

Absence of Eastern Hemlock

Cabot Head

Hope Bay

Floristic Quality - Invasives

•

Low level of non- native (4-16%)

•

Concern for invasives

–

primarily Halton▫

Dog-strangling vine

▫

Common Buckthorn

▫

Garlic Mustard

02

46

810

1214

16

Ac c e s s 5 0 m 1 0 0 m 1 5 0 m 2 0 0 m P l o t

Transect Segment

Spec

ies R

ichn

ess

Hockley ValleyHilton FallsSkinner Bluff

Non-native Species

Results•

Mature, healthy, sugar maple dominant

•

Diversity highest in southern forest

•

Gap-replacement •

Increasing age –

size

•

Within threshold of healthy forest

•

Predominantly native vegetation cover

open slope forest

vegetation association

debris slidenutrient poor

structure and/orprocess

riparianforest

successionalslope forest

riparianforest

upland forestrim/cliff forest

low energystream

debris slidenutrient rich

stress

dist

urba

nce

habitat favourableness

habi

tat d

urat

iona

l sta

bility

upland plantationrim forest

cave/crevass

slope forest

upland forest upland forest

glacial depositwindthrow

shallow bedrockkarst toppling

slump

flooding

shallow bedrockselective logging

shallow bedrockblockfall

talus

glacial deposit shallow bedrock

Permanent habitats

Temporary habitats

stressdi

sturb

ance

habitat favourablenessha

bitat

dur

ation

al s

tabil

ity

upland

riparian/valley

slope/cliff

General trends of Escarpment units. The lines are not inclusive, valley and slope sites could also be found in the low stress/low disturbance zone.

key

RecommendationsManagement Strategies•

Formalize and coordinate forest management plans▫

Interim management strategies

▫

Park management plan

▫

Forest agreement and management plans

Land Use•

Reduce human disturbance regimes▫

Minimize tree cutting in ANSI

•

Passive, low-impact recreation –

hiking trails through less sensitive landscape

Recommendations

Invasives•

Action on invasives

–

Halton

Agreement Forest

•

Spread of invasive along trail –

careful planning or re-routing

Partnerships•

Promote data-sharing with other agencies monitoring forest health

•

Maintain partnership with Universities – education component