A FOREST ECOSYSTEM GUIDE FOR THE AMOS LOWLANDS ECOLOGICAL REGION, NORTHWESTERN QUEBEC: A FOREST MANAGEMENT APPROACH PIERRE CARTIER and B R I A N D. H A R V E Y Unitd de recherche et de d~veloppement forestiers de l'Abitibi-Tdmiscamingue, Universitd du Quebec en Abitibi-T~miscamingue, Rouyn-Noranda, Qudbec, J9X 5E4, Canada and YVES B E R G E R O N Groupe de recherche en ~cologie forestidre, Universitd du Quebec ~ Montreal, C,P 8888 Succursale "it', Montreal, Qudbec, H3C 3P8, Canada

Abstract. In Quebec, forest stations are defined as forest units that are reasonably homogeneous in terms of forest composition and site characteristics - as expressed by surficial deposit and moisture regime - and within which similar operational constraints for silvicultural potential and productivity levels may be expected. In the course of developing a field guide to the forest stations of the Amos Lowlands Ecological Region in northwestern Quebec, classifications of 12 site types and 72 forest stations (38 forest cover types or 16 general cover types) were developed. The classifications were based on a hybrid approach involving cluster analysis of forest ecological units inventoried in subregional studies, classical classification and ordination analyses performed on a regional biophysical inventory database, and empirically associating forest cover types to site types. The guide, while similar to other published forest ecosystem classification guides, emphasizes forest dynamics by presenting forest stations common to a given site type according to their successional stage. Field keys and general interpretations of forest potential and operational constraints are included in the guide. A summary description of the guide and accompanying documents is provided. A first draft has been distributed recently for feedback from industrial and government foresters and researchers in the region. Analyses of inventory data is continuing and modifications will be incorporated into a second draft before publication in 1995.

I. Introduction Forest managers are increasingly being confronted with the compounded pressures of multiple use interests on forest land and greater restrictions on the manner in which they intervene in the forest. In Quebec a recently released forest policy document entitled the "Forest Protection Strategy" (Anonymous, 1994a) signals a new and important commitment on the part of the Ministry of Natural Resources (MNRQ) to bring forest management practices in the province in line with current environmental thinking. A key element of the forest protection strategy is the integration of fundamental ecological knowledge into forest management decision making as a means of developing silvicultural and management strategies that are more harmonious with natural stand and landscape dynamics. Environmental Monitoring and Assessment 39: 249-263, 1996. 1996 Kluwer Academic Publishers. Printed in the Netherlands.

250

PIERRE CARTIER ET AL.

To facilitate this integration and transfer of ecological knowledge, the Ministry has scheduled the development of forest ecosystem classification (FEC) guides for roughly 30 ecophysiographic regions in the province. The production of field guides is part of the Inventory Service's larger program known as the Forest Ecosystem Survey Program or Cadre dcologiqueforestier (Bergeron et al., 1992). Several pilot projects are currently underway to provide prototypes for other field guides that will follow. The most sophisticated classification and guide under development by Grondin and Saucier for the Appalachian region is based on an enviable productivity-oriented database. Cauboue and Tremblay's (1993) guide to the forest stations of the Upper North Shore (of the St. Lawrence) has had a positive reception from regional foresters while the field guide for the Laval University's Montmorency Forest (Lessard et al., 1991) was built on three decades of ecological work in the area and serves as a useful pedagogical and research tool. In the Abitibi region in northwestern Quebec, a field guide project was initially undertaken using an approach based on information contained in existing ecological studies (Harvey et al., 1996). The resulting classification was eventually modified when the MNRQ Inventory Service's biophysical inventory database was used to develop a forest typology for the region. This paper presents the hybrid classification and a description of the draft field guide to the forest stations of the Amos Lowlands Ecological Region.

2. Quebec's Ecological Framework: Some Definitions Like most other forest site classification programs, Quebec's Forest Ecosystem Survey Program (FESP) is hierarchically structured into perception levels. The conceptual foundation of the program is largely based on work by Jurdant et al. (1977) but has been considerably modified by the MNRQ in recent years (Bergeron et al., 1992). At the highest level of perception the ecological region is defined as an area of land with a distinctive climate as expressed by the vegetation. It is equivalent to the ecoregion defined by the Canadian Committee on Ecological Land Classification (Thibault and Hotte, 1985). There are 72 ecological regions south of 53~ in Quebec. The mapping scale is 1:1 250 000. The ecological district (mapped at 1:250 000), is characterized by a specific pattern of relief, geology and geomorphology and generally covers an area of 30 to 300 km a (B61and et aL, 1992). The physiographic zone combines ecological districts with similar relief and landform patterns and is delineated on ecological district maps. The following three definitions are directly related to the methods presented here. The finest unit in the FESP, the ecological phase, is defined as a land unit which is relatively homogeneous in terms of its soil as characterized by surficial deposit and soil moisture regime, and its current vegetation (Jurdant et al., 1977). The site type is the physical substrate of a forest station and is characterized by surface deposit, soil moisture regime and other soil and site parameters. By

ECOSYSTEM GUIDE FOR THE AMOS LOWLANDS 77* I

1 49*

251

Black spruce - Mosses Domain

ii~i~i~ii~i~i~ii~iiiiIiiiiii~iii~i~i~i~i~i~i:iI~i~i~ii~ ~i~i~ii~ii~i~i~!i~i~i~i~i~ii~i~!ii~i~i~i!i~ii!!i~. iii~iiiiii!iii!i!~!iii!!iiiiiiiii!i/!/iiilii~ ~iiiii~;i|~i'i~i"fl'~;:':"~-fi'l'~ b i r c h D o m a i n 48*

IIIIIII1~~'~

IIIIIIl Il i P ' / ~

. ~ / ~

Yellow birch - Balsam lit

zones..... ~ Flavrisn Lake Hills Blmard Lake Hills [] Belleterre Lake Hills ~7~Satpourln Lake Plain

'~?Yellow birch pornaln

Fig. 1. Amos Lowlands Ecological Region showing physiographic zones and forest domains (according to Thibault and Hotte, 1985).

definition, the site type presumes a specific successional series and known or assumed productivity range, as well as management constraints and capabilities. The forest station is described as a land unit that is relatively homogeneous in terms of vegetation and site characteristics and for which a given silvicultural strategy is appropriate (Delpech et al., 1985).

3.

Study Area

The Amos Lowlands Ecological Region (8cl) is situated in northwestern Quebec between 48~ to 49~ latitude and 77~ to 79~ longitude and covers an approximate area of 15 000 km 2 (Figure 1). It is part of the Middle Humid Boreal Ecoclimatic Region (Anonymous, 1989) and the Balsam fir (Abies balsamea L.) - White birch (Betula papyrifera Marsh.) Domain (Thibault and Hotte, 1985). To the north it is gradually replaced by the Black spruce (Picea mariana (Mill.) BSP) - Moss Domain and to the south by the Yellow birch (Betula alleghaniensis Brit.) - Balsam fir Domain (Thibault and Hotte, 1985). Relatively little is known about the history of regional occupation by indigenous peoples. Major human settlement of the region only began in the 1920s and much of the region's secondary forests of trembling aspen (Populus tremuloides Michx.) and white birch date to a 30-year period of extensive land clearing for agriculture. In effect, relatively little of the region has escaped land clearing, human-caused or natural fires, or commercial forest harvesting over the past 70 years. Today

252

PIERRE CARTIER ET AL.

much of the cleared farmland has been abandoned and over the past 25 years the forest industry has replaced agriculture as the principal modifier of the forest landscape. Fire and spruce budworm (Choristoneurafumiferana) outbreaks are the principal natural agents of disturbance (Dansereau and Bergeron, 1993). According to Bergeron (1991), the natural fire cycle is probably around 100 years, which is considerably higher than more easterly parts of the Balsam fir Domain where annum precipitation is higher. Three spruce budworm outbreaks in this century, of which the most recent occurred in the 1970s and 1980s, have been documented for the region by Morin et al. (1993). During this outbreak most mature balsam fir stands were severely defoliated in the region and extensive salvage cutting operations were undertaken to harvest large volumes of dying timber. The Amos Lowlands Ecological Region occupies the southern half of the Abitibi Geological Domain which is part of Superior Lake province, the oldest tectonic province of the Canadian Shield (Simard et al., 1990). The bedrock is composed of 27 billion year old volcanic and sedimentary rocks and of plutonic intrusions that occurred throughout its formation. The region is also situated in the Great Clay Belt, a large physiographic zone characterized by deep silty clay deposits that were precipitated during regional occupation by the pro-glacial Lake Ojibway (Vincent and Hardy, 1977). Other surficial deposits such as glacial tills and fluvio-glacial sands were reworked by the waters of Lake Ojibway and are often overlain by varying thicknesses of these finer glacio-lacustrine deposits. Elevation generally plays an important role in whether or not tills and other deposits are situated at the soil surface or under a layer of clay. Roughly half (53%) of the region is covered with glacio-lacustrine deposits; the rest of the surface area consists of rock outcrops (7%), and organic (16%), till (11%), and fluvio-glacial (6%) deposits. There are five physiographic zones in the Amos Lowlands Ecological Region (Figure 1). The Bell River Plain, a large physiographic zone characterized by lacustrine plain clay deposits, covers the northern three quarters of the Amos Lowlands. Outcrops and small hills covered with reworked till are scattered throughout this zone but are much more frequent in other physiographic zones to the south and southwest with more varied topographies.

4. Methodology The classification of forest stations for the Amos Lowlands was developed using a hybrid approach involving two phases, the first of which is described in detail by Harvey et aL (1996). Briefly, this phase consisted of exploiting information available in existing sub-regional ecological studies: One hundred and seven forest ecological units or ecological phases identified in four studies (Lafond and Ladouceur, 1968; Gaudreau, 1979; Massicotte, 1982; Bergeron et al., 1983) were listed, standardized to a common nomenclature, evaluated for a variety of silvicultural and environmental interpretations, and classified using hierarchical cluster

ECOSYSTEM GUIDE FOR THE AMOS LOWLANDS

253

analysis (Legendre and Legendre, 1984). This classification produced 29 units whose site characteristics were relatively homogeneous but whose forest component was somewhat less so (Harvey et al., 1996). While not providing a definitive portrait of forest stations in the Amos Lowlands, we assumed that the analysis did provide reasonably complete - although simplified - coverage of site types in the region. Infrequently encountered site types such as poorly drained tills, colluvial (talus) deposits, and shallow clays were considered to be of marginal importance and thus not included in the site type classification. In all, 12 site types were identified, each characterized by surficial deposit type and a broad moisture regime class (Figure 2). Other environmental attributes were associated with the site types, including topographic position and soil properties such as texture, stoniness, fertility, depth, and humus type and humus depth. This site type classification formed the abiotic underpinning for the second phase of the forest station classification. The second phase consisted of analysis of the MNRQ Inventory Service's biophysical inventory database for the region and integration of the resulting forest typology with the site type classification. Vegetation and site data were collected in 1991 and 1992 from 982 sample plots distributed throughout the region. Nolet (1994) developed a regional forest typology using standard classification and ordination techniques - indicator species analysis and detrended correspondence analysis - as described by Bergeron et al. (1992). Seventy-six forest types were identified, each representing a particular combination of dominant cover and understory species. Distributions of forest types across the 12 site types were generally large with some exceptions (Table I). The biophysical database was reviewed and forest cover types (without reference to understory species) were associated empirically with the 12 site types. All forest cover types associated with a given site type were then associated with a successional stage: pioneer, intolerant, intermediary sub-climax, and climax (Table II). These successional classes are not explicitly linked with stand age but rather to stand composition and probable successional pathway (Anonymous, 1994b), and as such are meant to provide an indication of forest dynamics on a given site type. Many similar forest cover types that were associated with the same site type were grouped under a more general cover type. For example, in forest station (sf.) 2.10 (Figure 2), the cover type Sb-Ms includes forest cover types Sb, Sb-Pj and Sb-B. Most forest stations from the initial classification (Harvey et al., 1996), including some that were not identified in the forest cover typology (e.g., black ash on alluvial sites), were retained in this classification.

Sfl.0 Sb

St3.0 B

2-3 1A23

2-3 R1A23

Sf2.O B

Deep till

Shallow t~ll

Sf4.0 B-Sb

and glaciolacustrine send 1-3 2A13

-'lmdo-gleclel

SIB.oiB-Sb

Gleciclacustrine sand 4-5 4GS45 Bf6.0 B

Gleciolacustrine clay 2-3 4GA23 St7.0 B

Gleciolecuatdne clay 4-5 4GA45

Edcecnee 8pp.

Willow, Edceceae spp.

; Mountain : maple, Raspberry. Low shrubs

Alder. Willow, Grasses. Raspberry. Herbs

app.

Alder, Rhamnus

Sffi.0 Ab

4-6 3A46

Alluvial

Sflti.ti Ce

6 7F-h6

Sf11.0 Sb

6 7Era6

Sf12.oiSh

6 7EM

Grasses, Aider, Willow, Edcecese app.

SI9.30 L SI9.31 Mh

Sf9.20 P ~ SI9.21 L-Sb Sf9,22 MIh

spp., Grasses

app., Grasses

Fig. 2. Forest stations and site types on a simplified toposequence.

Edcaceae spp.

Hardwood Ab: Black ash Bw: White birch Mh: Mixed intolerant hardwood Pot: Aspen

Efl~e

Alder, Willow,

Sf11.30 L

Edceceae

Alder, WUlow,

Sfl0.30 L

$f10.20 L-Sb Bf11.20 L-Sb Sf12.20 L-Sb

Bfg.10 Sb-Ms ~.i10.10Sb-M Sf11.10 Sb-L Sf12.10 Sb-L Bt9.11 M|8

Stg.ti ~

5-6 7T56

..~. "" ~'-,-'~.'; :r .~,"."~o.~:o.~ -" "' :'"~.~'-~'-~'-~'- '.-;'::..-;.:';..-;,::.~ ~-~'-~'-~'.:-~'-I Shallow Humlc Mesic Fibric organic Organic organic organic

9-.,~.~-,~.:...:.~t,:.

~~--F------,:--~:======.

Abbmvle0ons of general cover types (Adapted ~om Quebac's Integrated inventor~ atra0flce0on (Anom. 19941)): Softwood Softwood Mlxeawood B: Balsem fir PJ:Ja: Jack pine MIh: Mlxedwood (intolerant hardwood dominance) B-Sb: Balsam 0r - Black spruce Pj-Sb: Jack pine - Black spruce Mla: Mlxedwood (softwood dominance) Ca: Eastern white cedar Sb: Black spruce L: Larch Sb-Ms: Black spruce - Mixed actlwood L-Sb: Larch - Black spruce Sb-L: Black spruce - Larch

Mountain maple, Raspberry

Pioneer stage Blueberries Pin cherry, Kalmle app. Edcec4me q3p

Sf6.30 PJ Sf6,31 Mh Sf6.32 Pot

Si7.30 L S17.31 Mh Sf7.32 Pot

5f3.30 PJ Sf3.31 Mh

Sl2.30 P~ Sf2.31 Mh

Sfl.30 PJ Sfl.31 Bw

Sf5.30 P~ Sf5.31 Mh

Fores~stations intolerant stage Sf4.30 P~ Sf4.31 Mh

Sr7.20 q-Sb Sf7.21 L-Sb Sf7.22 MIh

Intermedillry ~llge Sfl,21 MIh

Forest ststlo~s Sfl.20 PJ-Sb $f'/..20 PJ-Sb Sf3.20 Pj-Sb Sf4.2O P~-Sb S15.20 PJ-Sb SI6120I~-Sb Sf'L21 MIh Bf3.21 MIh Sf4.21 Mih Sf5.21 Mih SI6.21 MIh

Forest ststk~s Sfl.10 Sb-Ma 512.10 S~.Ms Sf3.10 Sb-Ms St4.10 S~Ma SfB.10 Sb-Ma Sf6.i0 Sb-Ma St7.10 St-Ms Sub cllmm( s ~ e Sf1,11 MIs BI2.11 MIs SI3.11 MIs Sl4.11 MIs Sf5.11 Mis Bf6.11 Mis St7.11 MIs

Forest slations Climax stage

Outcrops, Surface very shallow soil over ~. deposit bedrock Molstum regime 0-1 (/) Abrevlationa R01

- ..! ~

m -t ;>

>.

;0

t~

255

ECOSYSTEM GUIDE FOR THE AMOS LOWLANDS

TABLE I The distribution of jack pine-black spruce forest types (Nolet, 1994) across site types for the Amos Lowlands Ecological Region. Site ty~es

Forest

types

jack pine

1

- black

EPN/LEG

PLS

SPS

1

PIG

EPN/KAA

VAM

PLS

1

PIG

EPN/KAA

VAM

CLR

6

PIG

EPN/CON

MAC

PLS

PIG

EPN/AUR

RUI

RIG

sample

3

4

5

6

7

8

9

i0

ii

12

Total

spruce

PIG

Total

2

(see f i g u r e 2)

plots

Legend: Code Trees EPN Picea mariana PIG Pinus banksiana

8

1

1

2

2

1

17

3

6

13

1

2 2

3

5

8

30

2

4

8

2

1

8 21 6

Code AUR

KAA LEG RIG RUI

VAM

3

Shrubs

Alnus rugosa Kalmia angustifolia Ledum groendlandicum Ribes glandulosum Rubus idaeus Vaccinium myrtilloides

1

29 5

3

Code CON

MAC Code CLR PLS SPS

1

69

Herbs

C o m u s canadensis Maianthemum canadense Mosses

Cladina rangiferina Pleurozium schreberi Sphagnum spp.

5. Results and Discussion 5.1.

CLASSIFICATION UNITS

The final classification was composed of 38 forest cover types grouped into 16 general cover types situated on the 12 site types. The use of general cover types was preferred over Nolet's (1994) forest types for three principal reasons: 1) the general lack of correspondence between site types and forest types (Table I); 2) the fact that cover types correspond with mapping units on forest cover maps (1:20 000) produced by the Inventory Service; and, 3) the greater familiarity of regional foresters with the forest cover type nomenclature. Regional consultation with foresters revealed a certain resistance to a new, unfamiliar nomenclature for forest stations. Consequently as a means of facilitating acceptance of the classification, the MNRQ's forest ecosystem nomenclature (Anonymous, 1994c) was used; it is familiar to users of forest cover and integrated forest ecosystem maps. This underlines an important compromise in the classification: We have opted to simplify the classification to suit the users' (cartographic) perception of the forest landscape rather than force foresters to refine their perception of field reality. Nevertheless, Nolet's (1994) forest typology may be of greater utility for questions concerning habitat suitability and will be included in the field guide. Further anal-

256

PIERRE CARTIER ET AL.

TABLE II Distribution of forest cover types across site types for the Amos Lowlands Ecological Region. Successional Stage

z

Site 1

ty~es

2

3

4

9

23

7

I 4

7 13

5 7

Forest Hardwood BW FH Mh Pot

cover

Sixodwood Bw-Sb Bw-Pj Bw-Ms Bw-B Mh-Sb Mh-Pj Mh-Ms Mh-B Pot-Sb 2 Pot-Pj 1 Pot-Ms 2 Pot-B

domln,ted 2 1 2 2 2 1 2 2

Si~edwood Sb-Bw Sb-Pot 3 Pj-Bw Pj--Mh 1 Ms-Bw Ms-Pot 3 B-Bw B-Mh B-Pot

do, In,ted hM soft~od 3 2 5 1 5 1 2

by intolerant ii 1 1 6 4

1 4 i 1

i 2

2 1

3

2

3 3 3

2

hardwood 8 1 5 3 10 7 i 1 2 1 1 1 I i 2 1 1 3

16 2 3 1

6

7

4

(see 8

figure

2)

9

I0

2

1

ii

12

2 3

1

16

4 2 4 50

Total

1

i

4

1

I 8

1

50 6 17 93

4 2

26 6 12 33 2 3 3 2 9 7 4 22

1 2

1 1 1 3 1 5

2

12

1

2

9

1

35 13 8 1 3 4 18 1 3

1 i

1

4 3-4 3-4 3 3 3-4 2 1 2 1 3 3-4 4

ty~es

2

1 4 1 1

Softwood Ce Ce-B Sb Sb-L Sb-Pj Sb-B L-Sb L Pj-Sb Pj Ms-Pj B-Sb B Totals' ~Sample plots

5

2 2

1 1

1

8 1 2

5

2 1

1

7 1 1

8 59

1 1

2 2

9

i0

16

9

2

4 2

6 3

i0 4

3 5

8 6

2

i

32 76 141 i19 18 at the r e g e n e r a t i o n stage omitted.

92

1 24 1 2 6

58 7 1 ii 2 1 1

3 9 1 4 9 168

9

3 4 113

11 2 1 1

15 1 2 1 4 3

17

27

5 1 2 1 3

1 12

2 1 165 13 23 24 i0 8 42 77 1 9 13 769*

Legend= Successional

stauea:

1 - Intolerant,

2 - Intermediary.

3 - Sub-climax,

4 - Climax.

S~or Ab B Bw Ce L

B l a c k ash B a l s a m fir White birch Eastern white Larch

cedar

Mh MS Pj Pot Sb

Mixed hardwoods Mixed softwoods Jack pine Aspen B l a c k spruce

ysis o f the Inventory Service's regional biophysical database will be undertaken to clarify relationships between the forest typology and site variables.

E C O S Y S T E M G U I D E FOR T H E A M O S L O W L A N D S

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A forest ecosystem guide for the Amos Lowlands Ecological Region, northwestern Quebec: A forest management approach.

In Quebec, forest stations are defined as forest units that are reasonably homogeneous in terms of forest composition and site characteristics - as ex...
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