Download ecosystem (site) classification

Tullamore, Ireland
June 2008
ECOSYSTEM (SITE) CLASSIFICATION:
PRINCIPLES, CONCEPTS, RATIONALE,
SYSTEM, AND ITS DEVELOPMENT;
APPLICATIONS IN FOREST
RESOURCES MANAGEMENT
K. Klinka
Professor Emeritus, UBC Forest Sciences Department,
Vancouver, BC
Preamble
• Without classification there can be no science of
vegetation (Daubenmire 1959)
• Without classification there is no science of
ecosystems and ecology. And indeed, no science
(Krajina 1960)
• We ought to make full use of what has been already
discovered, while endeavouring to find what has not
(Unknown)
Outline
1.
Principles, Concepts, and Rationale
2.
Development of Ecosystem Classification
3.
The Classification System
4.
Application of the Classification
1. Principles, Concepts, and Rationale
• What is ecosystem?
• How to study ecosystems?
• How to classify ecosystems?
• Rationale for ecosystem classification
1. Principles, Concepts, and Rationale
What is ecosystem?
• Classification requires that the concept of what is to be
studied be defined; different concepts (definitions) would
result in different classifications (and confusion)
• Local ecosystem: a landscape segment relatively
uniform in climate, soil, vegetation, animals, and
microorganisms
A Local Ecosystem
1. Principles, Concepts, and Rationale
• Vegetation and soils are the most easily studied
ecosystem components and thus form the basis for
ecosystem classification
• Local ecosystem; what is the size of local a ecosystem?
• Ecosystem sampling − the sampling of vegetation (sample
plot) and soils (pedons)
• Regional ecosystem: a group of contiguous local
ecosystems affected by the same regional climate
1. Principles, Concepts, and Rationale
•
If a population of ecosystems in the landscape is very large and the
variation within a population is great, we group individual
ecosystems that are alike in selected characteristics
•
Classification frames classes of similar ecosystems, and
characterizes and names these classes. When there are too many
classes, a hierarchy of classes is created
•
Some property must chosen as the basis for grouping – differentiating
characteristics; it should be associated with a number of co-varying
properties, i.e., accessory characteristics
1. Principles, Concepts, and Rationale
•
What is the difference between taxonomic and interpretive
classifications?
• Taxonomic classification are developed from bottom to top
• What are the characteristics of a good classification?
• Classification organizes ecosystems in way that shows the greatest
number of relationships in the most important properties
• Classification establishes order. Order wherever it reigns, brings
intellectual beauty with it (Duhem 1974)
1. Principles, Concepts, and Rationale
• Understanding forest ecosystems means understanding vegetationenvironment relationships and vegetation succession
• Forest (Ecosystem) management requires ecosystem-specific
approach
•
The application of an ecosystem-specific approach requires that a
forest be stratified into ecologically uniform segments. In
consequence, management of that forest can be simplified and, at the
same time, given a sound ecological foundation
•
A consistent and ecological meaningful stratification requires, in
turn, an appropriate ecosystem classification system
2. Development of Ecosystem Classification - Approaches
•
•
•
Environmental approach (soil, landform, and site classification)
Vegetation approach (vegetation classification)
Combined approach (ecosystem or ecological classification)
•
Developed by V.J. Krajina and his students (1949-75) who sampled
and analyzed ecosystems across British Columbia
•
They considered all useful approaches and concepts of used by
Cajander, Braun-Blanquet, Clements, Pogrebnyak, and Sukachev
•
The resulting uniform classification system improved our
understanding of vegetation-environment relationships and
vegetation succession and provided a framework for
ecosystem-specific management in British Columbia
V.J. Krajina
2. Development of Ecosystem Classification
•
The system was adopted by the BC Ministry of Forests around
1976
•
The reason for the adoption was providing applicable tools (field
guides, indicator plant species, and training) for ecosystem
identification and silvicultural decision-making
•
The system gave impetus to develop comparable versions across
Canada
•
A modified version of the system (Ecological Site Classification) is
used in Great Britain since 2001)
3. The Classification System
What is biogeoclimatic ecosystem classification?
•
The system that organizes ecosystems according to
relationships in climate, vegetation, site quality, (and time).
•
The system includes three independent but integrated classification:
climatic, vegetation, and site
•
The system is vegetation driven as plants integrate best the
combined influence of numerous environmental factors
3. The Classification System
Concepts and elements of the system:
•
•
•
•
•
•
•
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Site factors that directly affect vascular plants
Site quality and ecological equivalence
Climate
Soil moisture regime
Soil nutrient regime
Zonal concept
Indicator plants
Edatopic grid
Structure and Hierarchies of the System
A topographic sequence
showing location of
vegetation units along the
local climatic, soil moisture,
and soil nutrient gradients.
A site-specific chronosequence of
vegetation units along the time
gradient.
A section of landscape showing locations
of three biogeoclimatic subzones (1, 2,
and 3) recognized on the basis of
distribution of zonal ecosystems. Each
segment features a variety of ecosystems
(as shown on the left) where vegetation
may be in various successional stages
(as shown on the right).
3. The Classification System
Vegetation Classification
Plant orders recognized in coastal BC:
•
•
•
•
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Quercus garryana
Pseudotsuga menziesii - Mahonia nervosa
Tsuga heterophylla - Rhytidiadelphus loreus
Tsuga mertensiana
Thuja plicata - Tiarella trifoliata
Populus trichocarpa
Pinus contorta
Vegetation Classification - a Pinus contorta ecosystem
Zonal Classification - Zones of British Columbia
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
Alpine Tundra
Spruce-Willow-Birch
Boreal White and Black Spruce
Sub-boreal Pine – Spruce
Sub-boreal Spruce
Mountain Hemlock
Engelmann Spruce – Subalpine Fir
Montane Spruce
Bunchgrass
Ponderosa Pine
Interior Douglas-fir
Interior Western Hemlock
Coastal Douglas-fir
Costal Western Hemlock
Zonal Classification - Zones of British Columbia
Site Classification - Edatopic Grid
Site Classification - a Cladina/slope-rocky site
Site Classification - a Lysichitum/gleysolic site
4. Application of the Classification
•
The system is widely used because it provides the best tool for the
application of the ecosystem concept
•
Research carried out in support of the classification and its
applications: quantitative characterization of soil moisture and nutrient
regimes, shade tolerance, and forest productivity
•
Silvicultural prescriptions identifying sites are legal documents for any
crown-land area to be treated
•
The classification has been followed by ecosystem mapping (GIS)
•
The classification provided a framework for a variety of research as
well as for portability of knowledge and past experience and research
4. Application of the Classification
Site Identification
1.
2.
3.
4.
5.
Stratify an area into environmentally uniform
segments.
Identify biogeoclimatic unit (subzone) for each site by
locating the site on a large scale zonal map.
Estimate soil moisture and nutrient regimes of each
site by considering selected environmental properties
and indicator plant species.
Consider other environmental factors which may
influence vegetation and/or management.
Identify site unit on the appropriate edatopic grid.
4. Application of the Classification
Identifying quality of a cutover site
4. Application of the Classification
- Site Identification
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Actual vegetation unit: Epilobium (stand initiation stage)
Zonal unit: Very Wet Maritime Coastal Western Hemlock
(CWHvm) subzone
Soil moisture regime: fresh
Soil nutrient regime: medium
Other environmental factors: zonal
Site unit: Hemlock – Blueberry/zonal
01/zonal
4. Application of the Classification – Regional Guides
Edatopic grids for the CWHdm subzone
upland sites, fluctuating water table sites, and floodplains
4. Applications of the Classification - Instructions of Silvics
Edaphic amplitude of Populus tremuloides
4. Application of the Classification
Tree Species Selection
Selecting the best tree species for regenerating a forest
is a critical management decision. It requires that
• Ecological characteristics of forest trees, sites and
ecosystems are known, and
• The management intent, strategy, and objectives are
defined
The criteria adopted for the tee species selection are:
• Maximum sustainable productivity
• Crop reliability
• Silvicultural feasibility
4. Application of the Classification – Tree Species Selection
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What is the climatic amplitude of potential species?
What is the edaphic amplitude of these species?
What is the shade tolerance of these species?
What are protection requirements of these species?
What is the growth pattern of these species?
What is the reproduction capacity of these species?
The species (or their combination) are selected that are
ecologically viable, conform to the management
goals, and fulfil the adopted criteria
4. Application of the Classification – Climatic Considerations
4. Application of the Classification – Climatic Considerations
4. Application of the Classification – Climatic Considerations
4. Application of the Classification – Edaphic Considerations
4. Application of the Classification – Edaphic Considerations
4. Application of the Classification – Edaphic Considerations
4. Application of the Classification – Site Preparation
4. Application of the Classification –Tree Species Selection
Douglas-fir is a protection-requiring on very dry sites
4. Application of the Classification –Tree Species Selection
Western hemlock is to be avoided on very dry, moderately dry, wet
sites, and nitrogen-rich sites.
4. Application of the Classification –Tree Species Selection
Western redcedar is to be avoided on very dry and moderately dry
sites but favoured on all other sites
4. Application of the Classification –Tree Species Selection
Western redcedar is easy to regenerate by planting but may require
protection from browsing
4. Application of the Classification –Tree Species Selection
Second-growth western redcedar stands are rare in the CWHdm subzone
4. Application of the Classification – Forest Productivity
• Productivity of crop tree species on different sites is one
of the most desirable information for forest management
• Providing and predicting site indices for all crop tree
species for all site units in the province was one of the
most important contribution of the classification to forest
management (Dr. H. Chen’s presentation)
• Inquiry into productivity of mixed-species stand showed
that the growth of structurally stratified mixture of shadeintolerant and shade-tolerant tree species will likely
surpass that of single-species stands
4. Application of the Classification –Forest Productivity
Site index of coastal Douglas-fir on coastal sites in relation to site
quality – trophosequences
4. Application of the Classification –Forest Productivity
Response of coastal Douglas-fir on coastal sites to nitrogen fertilization
An edatopic grid showing six site series, pretreatment foliar N (%) and sulphate-S
(ppm), and isolines of relative basal area response indicating the third-year basal
area response of Douglas fir to fertilization with nitrogen.
Conclusions
• Classification does not increase our knowledge
about things; knowledge is only obtained by
studying the things
• Classification provides a logical tool to organize
existing knowledge in a way that is easily retained in
memory and is easy to convey through instructions
• A good classification should display intellectual
economy of thoughts; i.e., establishing order out of
apparent disorder and facilitate perceiving
relationships among the things studied