Green Island

A Flora and Fauna Inventory of Three Islands on Lake Clear (Green Island, Island F and Island G)

by: Chris Michener, July 2000

Compiled for the Lake Clear Conservancy

Three islands in Lake Clear, Green Island and Islands "F" and "G" also know as, the Twin Islands, have been identified by the Lake Clear Conservancy as candidates for long term conservancy. This report is an attempt to give the reader a picture of what these islands are like.

Lake Clear is one of the larger, cold water lakes in Renfrew County and the rocky shoals around islands such as Green Island are important Lake Trout spawning grounds. While it is not a deep lake, the depth in the middle being less than 100 feet deep, the western horizon is mountainous terrain.

The waters feeding the lake cascade down from one of the highest elevations in Ontario, approximately 1700'.

Geologically, Lake Clear is situated in Precambrian rock of the Grenville Province of the Canadian Shield. Specifically, the lake lies in a very narrow band of Nepheline (primary rock forming mineral) and alkalic syenites, running between Cobden and Bancroft. Turner Island, situated between Green Island and the Twins, was once mined for Berylium, a hard metal.

The lake is situated in the Great Lakes/St. Lawrence Forest Region and the water shed area is well forested with second growth forest. Farms are spotted throughout the area but form a minor percentage of the landscape. The ownership around the lake is mostly private.

A major White-tailed Deer yard is just east of Green Island and judging from deer tracks seen on the island, deer use Green Island from time to time.

A designated old growth forest is situated on the western shore of Lake Clear, which contributes a significant plant community to the natural history profile of the lake. One notices when boating to the islands, how unpopulated the south-eastern corner of Lake Clear is. Even though mostly privately owned, it appears wooded and wild. The main cottage concentration is in the north-western end, and elsewhere along the shore the cottages and homes blend in with the forest.

Map 1 illustrates positions of the 3 islands on Lake Clear

Green Island

According to a long time resident of the lake, a fire ravaged Green Island roughly 35 years ago. This is evident from the age of the trees which are young to medium. The tree composition is mixed with the main deciduous species being White Birch (see Green Island Plants in Appendix A). White Spruce, Eastern White Cedar and Balsam Fir are common riparian and interior species plus apparent survivors of the fire, a number of older Red and White Pines still inhabit the island. The shoreline, while being mostly treed, is interspersed with rock walls and sloping stone outcrops.

A beaver lodge is noted on amongst white cedars on east shoreline with birch, maple and other beaver preferred trees gone. White spruce dominant the south shore. The rock outcrops on the southwest part of the island has species such as Staghorn Sumac, Low Blueberry and Wild Columbine.

Rounding the southwest corner one comes upon the smallest of the island's two lagoons.

On the west side of the island, an impressive inlet opens into a lagoon, which I call here 'the large lagoon.' A fisherman, with whom I talked, had fished the lake for several decades and noted that there were very few minnows available. He maintains that the introduced Pickerel had severely diminished the number of minnows in the lake. If true, this shallow lagoon created important habitat for small fish, which were observed. However, the life of a minnow in this lagoon was still tough as at least three Belted Kingfishers and a Great Blue Heron were dining.

The lagoon whose bottom is sandy and stony, offers protection from the prevailing west wind. Average depth in the middle was about 1 metre. Submerged water plants of the shallows consisted of Canada Waterweed, Green fruited Bur-reed and Pondweed sp., with an algae sp. present in slightly deeper water. Sweet Gale was the dominant shrub of the shoreline at the eastern end of the lagoon and a number of sedges and grasses were present. Here, Green frogs were singing their banjo-like calls. Birds in the riparian zone of the lagoon were Mallard, Song Sparrow, Northern Waterthrush, Common Grackle and Swainson's Thrush. Three Swainson's Thrushes singing, presumed to be males on territory on this island, was exceptional. This neotropical, long-distance migrant is not common in Renfrew County, a little more widespread through the Algonquin Highlands and is common in the boreal regions of Ontario, where it prefers thick coniferous growth. The number of Yellow-rumped Warblers (5 singing males) was impressive. In Central Ontario population densities range from 0.25 to 1.0 pairs per hectare (Cadman et al. 1987), so this island of under 6 hectares reaches the upper limit of this warbler's population density.

The vegetation is diverse and varied on the 13 acres the island comprises. Northern Ladies' Tresses (Spiranthes lacera) were found growing on the southwestern peninsula, west of the wetland (see Map 3). The wetland is a small coniferous swamp. A wet muck soil with some standing water exists and hosts Broad-leaved Arrowhead, Bulb bearing Water-hemlock, Wild Calla, Swamp Milkweed, Curly leaf Dock, Marsh Bellflower, Swamp St. John's-wort and other wetland plants.

Human use was respectful as garbage was not evident. Two fire pits were established, one on the northwest corner, one on the east side, and both seemed to have been used with common sense and very little tree cutting was apparent.

Island F viewed from north side

This island witnesses the most human disturbance as campers have created a trail system, built a board and pit privy, and fire pits at tent sites.

The island is well treed with a good diversity of herbs (see Island F Plants in Appendix A). An understory of American Basswood, mostly shrub sized, was in contrast to Green Island and Island G where this species was absent. Also, Trembling Aspen was present here. Some of the interesting herb species were found along the rocky shoreline where they clung to a foothold. Common Bearberry, Pale Corydalis and Fragrant Cudweed were interesting finds.

A rare butterfly for Renfrew County was the Satyr Comma (Polygonia satyrus) spotted on Island F on July 13. This butterfly was known until this year by old specimens in a local collection (Michener, 2000). This was the first I had seen and lent some excitement to the day!

Conclusion

In general, Green Island has qualities that represent intriguing natural features. The 'big lagoon' is a wonderful place 'out of time'. It is unspoiled habitat for many plant and animal species. The wetland that links the two lagoons is full of little surprises such as Swamp Loosestrife (Swamp Candles) and Bulb-bearing Water-hemlock, a very poisonous plant. A number of plants are listed as rare by Moore (Moore, 1972, Rev. 1978) including Marsh Bedstraw (Galium palustre), Upland White Aster (Solidago ptarmicoides), False Nettle (Boehmeria cyclindrica) and Northern Willow-herb (Epilobium ciliatum).

The uplands on the island are varied in forest density as thick coniferous growth gives way to numerous rock outcrops. Round-leaved Dogwood was the dominant interior shrub, in places forming a thick wall. Birds were vocal and active (see Green Island Birds in Appendix B) nectaring bees and butterflies were abundant as well as other insects including damsels and dragonflies. This island will become a valuable natural resource as the pressures inherent in cottage development increase.

Islands F and G, the Twin Islands, are small, being less than 5 acres in size. One is a Herring Gull nesting location; the other, a rocky, well vegetated island. Island habitats are unique. Plants find their way there by unknown means as no land corridor is available. If plants disappear because of disturbance, they can't easily replace themselves. Diversity could be enhanced with the introduction of some native species.

Appendices

Plant code explanation:

introduced = not native to North America

OPLID = Ontario Plant List Identification Number (McMurray, S.C. and A. Lehela. June 1999)

status: c = common; u = uncommon; r = rare

These designations correspond to Moore (Moore, 1972, Rev. 1978) and are specific to northwestern Renfrew County, within 40 miles of the Petawawa Research Forest. I have used common, uncommon and rare for her abundance classes which are:

(3) the plant grows in many locations and/or is very common in its habitat;

(2) intermediate between 3 and 1

(1) the plant is rare because only one or two specimens have been seen or because it is out of its normal range and only found in one or two locations.

Bird survey methodology

Bird surveys were done on Green Island on July 11 and the Twin islands on July 13. The birds were mapped by song and sight by transects through the interior and boating along the shoreline. Bird species not listed may have been missed as mid-july is late in the nesting cycle so abundance is a bit misleading. The presence and abundance numbers should be considered a minimum.

Appendix A

Green Island Plant Survey

620 Common Dandelion Taraxacum officinale yes c

679 Spotted Touch-me-not Impatiens capensis

u

698 Speckled Alder Alnus incana

c

705 White Birch Betula papyrifera

c

837 Pennsylvania Bitter-Cress Cardamine pensylvanica

u

979 marsh Bellflower Campanula aparinoides

u

1009 Twinflower Linnaea borealis

u

1353 Round-leaved Dogwood Cornus rugosa

u

1355 Red-osier Dogwood Cornus stolonifera

u

1385 Easter White Cedar Thuja occidentalis

u

1701 Eastern Bracken-fern Pteridium aquilinum

c

1781 Spinulose Wood Fern Dryopteris carthusiana

?

1783 Crested wood fern Dryopteris cristata

u

1803 Oak Fern Gymnocarpium dryopteris

c

1808 Sensitive Fern Onoclea sensibilis

c

1828 Canada Soapberry Shepherdia canadensis

u

1861 Common Bearberry Arctostaphylos uva-ursi

u

1880 Low Blueberry Vaccinium angustsifolium

c

2021 Large Hop Clover Trifolium campestre yes u

2051 Red Oak Quercus rubra

u

2089 Pale Corydalis Corydalis sempervirens

u

2080 Currant sp. Ribes sp.

2193 Common St. John's-wort Hypericum perforatum yes u

2199 Swamp St. John's-wort Triadenum virginicum

u

2232 Canada Waterweed Elodea canadensis

u

2310 Multi-coloured Blue-flag Iris versicolor

u

2464 Northern Water-horehound Lycopus uniflorus

u

2503 Hooded Skullcap Scutellaria galericulata

u

2641 Bluebead-lily Clintonia borealis

c

2658 Wild Lily-of-the-valley Maianthemum canadense

c

2671 Hairy Solmon's Seal Polygonatum pubescens

u

2681 White Trillium Trillium grandflorum

c

2712 Blue Ground-cedar Diphasiastrum trisstachyum

c

2727 Ground Pine Lycopodium obscurum

c

2834 Sweet Gale Myrica gale

c

2861 White Ash Fraxinus americana

u

2876 Northern Willow-herb Epilobium ciliatum

r

2921 Rattlesnake Fern Botrychium virginianum

u

2944 CommonHelleborine Epipactis helleborine yes r

2984 Northern Ladies' Tresses Spiranthes lacera

u

3250 Balsam Fir Abies balsamea

c

3255 White Spruce Picea glauca

u

3263 Red Pine Pinus resinosa

u

3265 Eastern White Pine Pinus strobus

u

3268 Eastern Hemlock Tsuga canadensis

u

3644 Curly-leaf Dock Ruex crispus yes u

3663 Rock Polypody Fern Polypodium virginianum

c

3710 Pondweed sp. Potamogeton sp.

3800 Swamp Loosestrife Lysimachia terrestris

u

3812 Star-flower Trientalis borealis

c

3843 Green-flowered Pyrola Pyrola chlorantha

u

3844 Shinleaf Pyrola elliptica

u

3861 Red Baneberry Actaea rubra

u

3864 Thimbleweed Anemone cyclindrica

u

3872 Wild Columbine Aquilegia canadensis

u

3927 Tall Meadow-Rue Thalictrum pubescens

u

3970 Juneberry sp. Amelanchier sp.

4043 Common Strawberry Fragaria virginiana

c

4067 Silvery Cinquefoil Potentilla argentea yes c

4174 Purple Flowering Raspberry Robus odoratus

u

4220 Marsh Bedstraw Galium palustre

r

4256 Willow sp. Salix sp.

4414 Common Mullein Verbascum thapsus yes u

4480 Bitter Nightshade Solanum dulcamara yes u

4492 Green-fruited Bur-reed Sparganium emersum

u

4563 American Yew Taxus canadensis

u

4661 False Nettle Boehmeria cylindrica

r

4736 violet sp. Viola sp.

4763 Inserted Virginia-creeper Parthenacissus inserta

u

4931 Spotted Joe-pye-weed Eupatorium maculatum

u

6000 Algae sp. Chara sp.

Island "F" Plant Survey

OPLID common name scientific name introduced status

108 Staghorn Sumac Rhus typhina

c

182 Spreading Dogbone Apocynum androsaemifolium

u

264 Field Pussytoes Antennario neglecta

c

448 Fragrant Cudweed Gnaphalium obtusifolium

u

475 Field Hawkweed Hieraciuim caespitosum yes r

572 Goldenrod spp. Solidago spp.

620 Common Dandelion Taraxacum officinale yes c

698 Speckled Alder Alnus incana

c

705 White Birch Betula papyrifera

c

1057 Larger Mouse-ear Chickweed Cerastium fontanum yes u

1385 Eastern White Cedar Thuja occidentalis

u

1861 Common Bearberry Arctostaphylos uva-ursi

u

2020 Yellow Clover Trifolium aureum yes u

2021 Large Hop Clover Trifolium campestre yes u

2089 Pale Corydalis Corydalis sempervirens

u

2464 Northern Water-horehound Lycopus uniflorus

u

2893 Common Evening Primrose Oenothera biennis

u

2944 Common Helleborine Epipactis helleborine yes r

3250 Balsam Fir Abies balsamea

c

3255 White Spruce Picea glauca

u

3970 Juneberry sp. Amelanchier sp.

4043 Common Strawberry Fragaria virginiana

c

4067 Silver Cinquefoil Potentilla argentea yes c

4132 Smooth Rose Rosa blanda

u

4170 Common Raspberry Rubus idaeus

c

4248 Trembling Aspin Populus tremuloides

c

4414 Common Mullein Verbascum thapsus yes u

4419 Corn Speedwell Veronica arvensis yes r

4563 American Yew Taxus canadensis

u

4609 Basswood Tilian americana

u

Island "G" Plant Survey

OPLID common name scientific name introduced status

572 Goldenrod spp. Solidago spp.

620 Common Dandelion Taraxacum officinale yes c

705 White Birch Betula papyrifera

c

1057 Larger Mouse-ear Chickweed Cerastium fontanum yes u

1162 Lamb's Quarters Chenopodium album yes c

1385 Eastern White Cedar Thuja occidentalis

u

2893 Common Evening Primrose Oenothera biennis

u

3255 White Spruce Picea glauca

u

3283 Common Plantain Plantago major yes c

4067 Silver Cinquefoil Potentilla argentea yes c

4087 Rough Cinquefoil Potentilla norvegica

u

4414 Common Mullein Verbascum thapsus yes u

4480 Bitter Nightshade Solanum dulcamara yes u

Appendix B Birds of the Islands

Green Island Island F Island G

common name abundance

Appendix B

Birds of the Islands Green Island, Island F, Island G

Island Butterflies and Dragonflies

Island F Green

Green

European Skipper Northern Crescent

Hagen's Blue

Satyr Comma Little Wood Satyr

Argia moesta

Eyed Brown

Eastern Forktail

Dot-tailed Whiteface

Calico Pennant

Four-spotted Skimmer

White-faced Meadowhawk

References

Cadman, M. D., P. F. J. Eagles, F. M. Helleiner, 1987. Atlas of the Breeding Birds of Ontario, University of Waterloo Press, Waterloo. 617 pp.

Chambers, B., K. Legasy, C. V. Bentley, 1996. Forest Plants of Central Ontario, Lone Pine Publishing and Queen's Printer of Ontario. Edmonton. 448 pp.

Cobb, B., 1963. A Field Guide to the Ferns, Houghton Mifflin Co., Boston. 281 pp.

Cody, J. C., revised 1978. Ferns of the Ottawa District, Canada Department of Agriculture, Ottawa. 112 pp.

Geological Highway Map, Southern Ontario. Ontario Ministry of Natural Resources. revised 1979.

Hewitt, D. F., 1966. Rocks and Minerals of Ontario, Geological Circular 13. Ontario Department of Mines, Toronto. 108 pp.

Newcomb, L., 1977. Newcomb's Wildflower Guide. Little, Brown and Co. 490 pp.

Michener, C., revised 2000. Butterfly Checklist of the PAFN. Pembroke Area Field Naturalists, Pembroke. 3 pp.

Moore, M. I., revised 1978. Vascular Plants of the Middle Ottawa Valley and NE Algonquin Park, Canadian Forestry Service, Chalk River. 43 pp.

McMurray, S. C. and A. Lehela, 1999. Ontario Plant List, OMNR, Digital Version 1.0.

Newmaster, S. G., A. G. Harris, L. J. Kershaw, 1997. Wetland Plants of Ontario. Lone Pine Publishing and Queen's Printer for Ontario, Edmonton and Toronto. 240 pp.

Chris Michener

Chris Michener has been involved in flora and fauna surveys for 20 years. He has done contract work for The Federation of Ontario Naturalists, the Canadian Wildlife Service, the Teme-Augama Anishnabai of Temagami and the Ontario Ministry of Natural Resources. He is Past President of the Pembroke Area Field Naturalists and is currently on the Board of Directors.

He would also like to acknowlege the help of Ethan Anderman for assistance with plant identification.