using ecoregions to describe distribution and abundance table of

advertisement
ECOREGIONS – May 2011 USING ECOREGIONS TO DESCRIBE DISTRIBUTION AND ABUNDANCE The following is a summary of the ecoregions that occur in the Maritimes by province. The descriptions here are short and meant to give you the highlights Please use these to help you interpret and describe species distribution and abundance patterns. However, try not to get bogged down in the details. For some species their associations with ecoregions are straightforward (e.g., Fox Sparrows occur in the Highlands and Cape Breton Taiga regions as well as along the coast). For other species with broader distributions, like the Northern Parula, you won’t be able to attribute their distribution to a particular ecoregion so better to state that they are “widespread” and use the ecoregions to highlight areas of highest density (e.g., Densities are highest in the NB Valley and Grand Lakes lowland regions, with several other areas of high abundance in all three provinces. Further information and the source from which these descriptions were derived can be found at: www.gnb.ca/0399/OurLandscapeheritage/index‐e.asp [NB]; www.gov.ns.ca/natr/forestry/ecological/ecolandclass.asp [NS]; www.res.agr.ca/cansis/publications/manuals/1996/A42‐65‐1996‐national‐ecological‐
framework.pdf [p.86, PE] TABLE OF CONTENTS ECOREGIONS OF NB ........................................................................................................................ 2 Highlands..................................................................................................................................... 2 Northern Uplands ....................................................................................................................... 2 Central Uplands........................................................................................................................... 2 Fundy Coast................................................................................................................................. 3 Valley Lowlands........................................................................................................................... 3 Eastern Lowlands ........................................................................................................................ 3 Grand Lakes Lowlands ................................................................................................................ 3 ECOREGIONS OF NOVA SCOTIA ...................................................................................................... 4 Cape Breton Taiga ....................................................................................................................... 4 Cape Breton Highlands ............................................................................................................... 4 Nova Scotia Uplands ................................................................................................................... 4 Eastern ........................................................................................................................................ 5 Northumberland Bras d’Or Lowlands ......................................................................................... 5 Valley and Central Lowlands Ecoregion ...................................................................................... 5 Western....................................................................................................................................... 6 Atlantic Coastal ........................................................................................................................... 6 Fundy Shore ................................................................................................................................ 6 PRINCE EDWARD ISLAND ................................................................................................................ 7 Prince Edward Island................................................................................................................... 7 MAP OF MARITIME ECOREGIONS ................................................................................................... 8 1
ECOREGIONS – May 2011 ECOREGIONS OF NB
Highlands Mountainous area with characteristics of the boreal forest - Mount Carleton (820m) tallest peak in the Maritimes, average elevation is 500m - Shorter, cooler growing seasons with longer winters - Several major rivers originate in this area, few lakes, limited wetlands - Dominated by balsam fir, black spruce, white spruce, white birch, intolerant hardwood and softwood species - Mountain tops with shallow soils – pure black spruce or balsam fir - Hemlock noticeably absent Northern Uplands Geologically diverse with a mixture of species with northern and southern affiliations - Elevations average 150 to 300m (up to 522m) - Tolerant hardwoods – sugar maple, yellow birch at lower elevations - Coniferous cover at higher elevations – balsam fir, black spruce, white spruce - Northern range limit of red spruce, hemlock and beech - Wetlands occur along streams and rivers - Peatlands, salt marshes, coastal estuaries, some lakes - Restigouche and Upsalquitch Rivers Central Uplands Two geographically separate areas, both with mixed forests and characterized by trees with southern affinities - Elevations vary between regions, Caledonia Uplands average 300m (up to 400m) - Two separate areas, one in northwest NB and one in the southeast (Madawaska Uplands and Bay of Fundy) which have similar climates and support similar ecosystems - High precipitation - Cooler than valley lowlands but warmer than nearby northern uplands - Trees with more southern affinities (rather than northern coniferous) - Hardwood and mixed forest stands – with well‐developed understorey vegetation (mountain maple, striped maple and hobblebush) - Lower slopes and valleys support red, white and black spruce and balsam fir and hardwoods on upper slopes, ridges and hilltops - Cedar in swamps along little main Restigouche and Grand River watersheds - Low frequency of fires (restricts growth of trembling aspens and pines) - Oak, ash and hemlock in scattered locations - In north, limited wetlands – alder swamps are the most common or shallow open water - More diverse wetlands in the south – peatlands, juniper barrens - Madawaska and Saint John River Valleys 2
ECOREGIONS – May 2011 Fundy Coast Coastal climate, primarily coniferous - Primarily under 100m although coastal cliffs can be upwards of 300m - influenced by the Bay of Fundy - cool, moist climate = mainly coniferous - dominated by red spruce but also balsam fir, black spruce, white spruce and tamarack - Tolerant hardwood is rare Valley Lowlands Defining characteristic is diversity - Elevations vary; 572m at mount Cameron but elevations drop to 100m at ecoregion border (approaching Grand Lake Lowlands ecoregion) - Region flanks upper and middle Saint John River Valley - Many plants with southern affinities - Continental climate sheltered from maritime influences - Less precipitation, relatively warm - Mainly tolerant hardwoods and red spruce - Diversity of wetland types (Hampton‐Kenebecassis marsh, abundant peatlands in the southwest, shrub swamp, wet forest) Eastern Lowlands Coastal area, marshes and extensive peatlands - Elevation range of 150m to sea level - Coastal area with sand dunes, salt marshes and lagoons - Acidic soils – discourages tolerant hardwood stands (i.e., sugar maple, yellow birch and beech) - Boreal‐like species - Fire‐tolerant species (trembling aspen, red,white and jack pine plus black spruce) - Highest percentage of wetlands and peatlands Grand Lakes Lowlands Warm climate and widespread alluvial floodplains - Elevation range of 150 m to sea level - Grand Lake Basin and Oromocto watershed - Warmest climate in NB (longest growing season and highest temperatures) - Heat‐loving trees – ash, oak, silver maple, ironwood, basswood - Low relief = few tolerant hardwood ridges - Red maple, red spruce, hemlock, beech, sugar maple, white ash - White pine near eastern lowlands - Diversity of wetlands 3
ECOREGIONS – May 2011 ECOREGIONS OF NOVA SCOTIA Cape Breton Taiga Elevations over 450 m; stunted trees, raised bogs, barrens and extreme weather conditions - “Taiga” generally refers to the transition zone between boreal forest and tundra - Highest elevation in NS, most of region exceeds 425 m (max. 532m) - One of the coldest and wettest areas in NS - Short growing season and constant wind - Expanses of ombotrophic (cloud‐fed) bogs, stunted conifers and exposed bedrock - Wet areas are dominated by black spruce and larch, balsam fir dominates upper slopes - Krummholz– stands difficult to pass through - Bogs are moss bogs with low plants and sedges - High annual precipitation - climate as well as natural disturbances (e.g., windstorms and insects) shape the forest ecosystem in the region - No history of logging (stunted trees are of little economic importance) Cape Breton Highlands Elevations 300‐450 m; mountainous terrain;, boreal forest - Ecoregion includes varied topography of lowlands, steep slopes and plateaus - Average elevation 300 to 450m but extends to sea level - Similar to the taiga region (cooler temperatures, fog and precipitation) but less “harsh” - On the plateau, the forest is boreal, dominated by balsam fir followed by white spruce - Wetter areas dominated by birch and black spruce - Tolerant hardwoods as well as mixed woods on slopes - Natural disturbance = spruce budworm (1974 – last budworm outbreak which caused widespread balsam fir mortality until population crash in 1985) Nova Scotia Uplands Elevations 150 ‐ 300 m; warm summers; complex region with uplands and lowland; mixed conifer and deciduous forests - Elevations of 100 – 300m (with exception of Inverness Lowlands ecodistrict which is comprised of valley floors of rivers flowing from the uplands to the lowlands) - Hilly topography – creates microclamatic conditions (sheltered vs. exposed) - Wind and ice damage are limiting factors affecting tree growth on the Cobequid and Cape Breton hills (stunted forests of beech and sugar maple) - Complex region with uplands and lowlands with mixed conifer and deciduous forests : o Sugar maple, beech, red maple and yellow birch dominate hardwood hills o White spruce, red spruce, and balsam fir form mixedwoods with the above‐listed hardwoods on some valleys and slopes o Hemlock commonly in ravines o Red spruce, balsam fir, white pine and hemlock are common in areas with a hummocky terrain (Mulgrave Plateau, St. Mary’s River and Central Uplands) 4
ECOREGIONS – May 2011 o Black spruce and eastern larch occur on poorly drained soils o Also large areas of barrens caused by repeated burning Eastern South sloping upland interior in eastern NS; warm summers; primarily coniferous forest - Highest elevation is 220m - Consists of rolling till plains, drumlin fields, extensive rockland, wetlands and several freshwater lakes (eastern interior ecodistrict) - Removed from the immediate climatic influence of the Atlantic and thus characterized by relatively warmer summers - Predominantly coniferous forests with red and black spruce occupying most sites - Also scattered stands of hemlock, white pine and black spruce, and tolerant hardwood dominated by yellow birch and sugar maple are found in areas where conditions are appropriate Northumberland Bras d’Or Lowlands Sheltered lowland in northern NS; climate moderated by proximity to warm bodies of salt water, coniferous, deciduous and mixed forests - Most of ecoregion is low‐lying; elevations 25‐50m - Variable climate (warmer along Northumberland strait than Bras d’Or) - Black spruce forests throughout the region (large areas of poorly drained soils) - Also tolerant hardwoods and mixed stands of red spruce, hemlock, sugar maple, yellow birch and beech (particularly on slopes vs. black spruce in the lowland areas) - Soil moisture deficits in some parts result in fire tolerant species like Jack Pine (e.g., Cumberland County) Valley and Central Lowlands Ecoregion Lowlands sheltered from coastal climatic influences with warmer summer temperatures and milder winters than elsewhere in the province. - Includes Annapolis Valley and watersheds of the Minas Basin and Musquodoboit Valley - Elevation seldom more than 50m - Extensive bogs (exceeding 400 ha) in Hants County - Gently rolling topography - Warm summers - Wide range of forest species associations occur throughout the region - Poor drainage = red spruce and balsam fir; better drainage = hemlock, white pine, red pine - Overall (mainly because of poorly drained soils) black spruce and red maple predominate - Tolerant hardwood on ridges and upper slopes (sugar maple, yellow bird and beech) but these stands also include trees typical of wetter sites creating mixed woods - Lowland fire sites – red oak, red maple, red pine, jack pine, grey birch and black spruce - Wildfires = dominant natural disturbance (but reduced since European settlement) 5
ECOREGIONS – May 2011 -
Much is farmed and land reclamation along shores with the use of dykes Western Old growth “Maritime” forest prominent; also barrens, wetlands and extensive river system - Has some of the longest rivers in Nova Scotia - Elevations from 289 to 25 m (along Atlantic coast) - Significant portions in the southwest are covered by wetlands - Mild winters and warm summers are most typical but proximity to the coast makes climatic conditions variable - Red spruce, hemlock and white pine (distinctive “Maritime forest”) are more prominent here than anywhere else in NS; old growth forests - Stunted black spruce on bogs - Large tracts of red maple on wetlands associated with rivers - Conspicuous feature is extensive barrens with sparse forests of black spruce and white pine with a shrub and herb layer (fire suppression has led to more young forests in once barren areas) - Much of the area has been extensively logged Atlantic Coastal Coastal climate - Extends along the Atlantic Coast; seldom exceeds 5km in width except along the Cape Breton shoreline where the coastal influence can extend almost 20km inland - Slow spring warm‐up and the lowest number of growing days in NS - Subject to high winds, high humidity, salt spray and fog - Absence of red spruce delineates the region from the Western and Eastern Ecoregions - White spruce is the most common on exposed sites (coastal islands and headlands) - Black spruce and balsam fir forests with red maple and white birch common components of the understory - Along eastern shore balsam fir forms dense stands with small diameters - Eastern portion contains fens, bogs and salt marshes - Wet mineral soils = black spruce is the dominant tree - Also large barren outcrops with scattered conifers and heath vegetation (east) Fundy Shore Coastal climate - Narrow strip that wraps around the Bay of Fundy - Variable topography and up to 225m above sea level (North Mountain) - Cold waters delay spring arrival and fog frequent along the shore - Narrow band of forest, most notable on exposed cliffs, dominated by white spruce - Mixed wood forests of balsam fir, red spruce, red maple, white birch and yellow birch - Beech and maple at higher elevations - White pine and hemlock also present 6
ECOREGIONS – May 2011 PRINCE EDWARD ISLAND Prince Edward Island Highly influenced by ocean; extensive beaches and salt marsh systems, dominated by farmland - moderated by the Atlantic Ocean, perhaps even more so by the Gulf of St. Lawrence - undulating plain with elevations range from sea level to 142m - farmland occupies much of region (circa. 50%) - well‐developed sand dune and beach systems - salt marshes (more on south shore than north shore) - dwarf conifers prominent on west and north shores - black spruce and tamarack in wetland areas - some representative Acadian forest 7
Ecoregions
of the
Maritime Provinces
Northern Uplands
Central Uplands
Highlands
Cape Breton Taiga
Eastern Lowlands
Cape Breton
Highlands
Prince Edward Island
Valley Lowlands
Grand Lake Lowlands
Northumberland Bras D'Or
Lowlands
Nova Scotia Uplands
Fundy Coast
Fundy Shore
Valley and
Central
Lowlands
Eastern
Ecoregions
Western
New Brunswick
Atlantic Coastal
Cape Breton Taiga
Northern Uplands
Cape Breton Highlands
Central Uplands
Nova Scotia Uplands
Fundy Coast
Eastern
Valley Lowlands
Northumberland Bras D'Or
Lowlands
Eastern Lowlands
Grand Lake Lowlands
Prince Edward Island
0
50 km
Nova Scotia
Highlands
Prince Edward Island
Valley and Central Lowlands
Western
Atlantic Coastal
Fundy Shore
Download