Plants of the Limestone Barrens

Plants of the Limestone Barrens

A Presentation by John MaunderCurator Emeritus of Natural History

The RoomsProvincial Museum of Newfoundland and Labrador

The Limestone Barrens Habitat Stewardship ProgramConservation and Sustainable Ecotourism Conference

Plum Point, NewfoundlandOctober 12-13, 2006

Plants? … What plants? …

Cape Norman

At first glance, there’s almost nothing there!

Burnt Cape [photo: Pat Montegue]

But, when you begin to look more closely …

Watt’s Point

… usually MUCH more closely….

Watt’s Point

You’ll see an amazing garden of botanical treasures!

Flowers Cove

Some quite spectacular …

Redtipped Lousewort - Pedicularis flammea – Big Brook

Others pretty dull …

Glacier Sedge – Carex glacialis – Boat Harbour

But, what’s all the fuss

about?

Alpine Ragwort - Packera pauciflora – L’Anse aux Meadows

What makes these plants so special?

Dwarf Hawk’s Beard – Crepis nana – Burnt Cape

Aren’t they just like plants from other places?

Well … some are …

Common Dandelion – Taraxacum officinale – Raleigh

But most aren’t …It’s all a bit complicated

Northern Anemone - Anemone parviflora – Burnt Cape

Our limestone barrens species fall into about 5 special categories …

… grouped by their general distribution

near Eddies Cove West

1. Newfoundland Endemic “Limestone-Loving” Species

Species found only in Newfoundland, in the whole world!

Barrens Willow – Salix jejuna – Cape Norman

Fernald’s Braya – Braya fernaldii – Big Brook and Watt’s Point

Long’s Braya – Braya longii

Sandy Cove and Yankee Point

Burnt Cape

“Burnt Cape Cinquefoil” -Potentilla usticapensis … [or Potentilla pulchella var. pulchella]

… There are varying taxonomic interpretations

… so its endemic status is uncertain

… and, MAYBE?

2. Gulf of St. Lawrence Endemic “Limestone-Loving” Species

Species found only in the Gulf of St. Lawrence region (which includes the Newfoundland west coast and Strait of Belle Isle), in the whole world!

St. Lawrence Primrose – Primula laurentiana – Raleigh

Newfoundland Pussytoes – Antennaria eucosma

Cape St. George

Longleaf Arnica – Arnica lonchophylla – Humber Gorge

3. Disjunct “Limestone-Loving” Species

Species found both in some far-away place, AND in our area, with a BIG GAP in between.

Dwarf Hawk’s Beard – Crepis nana – Burnt Cape …. Disjunct to N tip of Labrador, and arctic and western North America

Newfoundland Orchid – Pseudorchis albida subsp. straminea

Burnt Cape - Disjunct to Greenland and one locality in Hudson Bay

Woolly Arnica – Arnica angustifolia subsp. tomentosa – Point Riche Peninsula … Disjunct to mountains of northwestern North America [photo: Rene Charest]

Pendantpod Oxytrope - Oxytropis deflexa var. foliosa – disjunct [from S Labrador] to N tip of Labrador, Gaspe, Hudson Bay, and low arctic and western North America

Bodin’s Milkvetch – Astragalus bodinii – Cook’s Harbour … disjunct to western North America

4. More Widespread “Limestone-Loving” Species

Calypso Orchid - Calypso bulbosa var. americana – Burnt Cape

Yellow Ladyslipper – Cypripedium parviflorum var. pubescens – Port au Choix

Small Roundleaf Orchis - Amerorchis rotundifolia – Burnt Cape

Frog Orchid – Dactylorhiza viridis

Killdevil Mountain [photo: M. Anions] and Burnt Cape

Purple Mountain Saxifrage – Saxifraga oppositifolia – Table Mountain

Tufted Saxifrage - Saxifraga cespitosa – Old Port au Choix

Island Gentian – Gentianopsis nesophila – St. John Bay

Alpine Chickweed – Cerastium alpinum subsp. lanatum – Lower Cove

White Mountain Avens – Dryas integrifolia

Sandy Cove [photo: N. Djan-Chekar] and Flowers Cove [photo: Pat Montague]

Yellow Mountain Saxifrage – Saxifraga aizoides – Eddies Cove West

Alpine Bearberry - Arctous alpina – L’Anse-au-Loup

Newfoundland Oxytrope – Oxytropis campestris var. minor – Mount Parent, P.Q.

Elegant Milkvetch - Astragalus eucosmus – L’Anse aux Meadows

Hairy Willow - Salix vestita – Port au Choix

5. Widespread Species which are not “Limestone Loving”

They’ll grow almost anywhere!

Larch – Larix laricina – Big Brook

White Spruce – Picea glauca – Table Head [photo: Pat Montague]

Living on the limestone barrens can be quite a challenge!

How do the plants manage it?

Trailing Juniper - Juniperus horizontalis – Port au Choix [photo: Pat Montague]

What conditions do they have to overcome?

Alpine Pussytoes – Antennaria alpina subsp. canescens – Watt’s Point

Many, it seems!

It is really useful to understand what makes barrens of ANY type, “barrens”.

Cape Norman

The first challenge is DRYNESS … even in areas that receive a lot of moisture

Burnt Cape [photo: Pat Montague]

Wind is usually the critical factor … especially in winter.

Eddies CoveIt’s not hard to tell how deep the sheltering snow gets in this area!

Even in summer, it helps to have a low profile to stay out of the drying wind, and within the thin, sun-warmed, surface air layer

Trailing Juniper – Juniperus horizontalis – Port au Choix [photo: Pat Montegue]

Tight cushion architecture can conserve a core of dampness within the cushion

Dwarf Hawk’s Beard – Crepis nana – Burnt Cape

Some plants find other ways to stay out of the wind

Flowers Cove, “White Rocks”

Laurentian Fragile Fern – Cystopteris laurentiana – Flowers Cove “White Rocks”

Other plants just grow smaller in exposed areas [while usually preserving flower size!]

Greenland Primrose – Primula egaliksensis – Cook’s Harbour and Boat Harbour

Hair creates a layer of dead air against the plant surface to help slow moisture loss when the plant’s pores are open

Rand’s Eyebright - Euphrasia randii – Cape St. Francis

Waxy and leathery surfaces help slow water loss from the surface

Netvein Willow – Salix reticulata – Lower Cove

Narrow leaves with less leaf surface area lose less water

Reddish Sandwort - Minuartia rubella – Port Saunders

The second challenge of the barrens is COLD.

However, cold is only partly a winter concern. For most arctic and alpine plants, once the temperature has dropped below a certain point, cold is just cold

W of Red Bay, Labrador, July 12, 2001

The main thing affected by cold is the total length of the growing season …

This photo was taken July 8 – and the willows are still just in early bud!

L’Anse-Amour, Labrador

Tight cushion architecture allows for a layer of “dead air”, within the cushion, that can warm up and stay warm all day

Moss Campion – Silene acaulis – Burnt Cape

Cold also leads to frost disturbance ….

Watt’s Point

… seen most dramatically in patterned ground

Burnt Cape [photo: Pat Montague

tap roots anchor plants deeply into the seasonally-disturbed frost-heaved soils

This rare species, the Cutleaf Fleabane, grows in Humber Gorge

Daubenmire (1941)

Some roots are contractile ... each time a plant is heaved upward by frost, the root of the affected plant shortens to pull the plant back down into the soil, where it belongs.

Long’s Braya – Braya longii – Yankee Point

The third challenge of the barrens is obtaining sufficient NUTRIENTS. Barrens usually occur on thin, poor soils.

Boat Harbour

The THINNESS of the soil is largely the result of ice-age glacial scouring …

Glacial Striae – Hawkes Bay

… and subsequent wind and water erosion.

Cape Norman

The POORNESS of the soil is usually the result of its basic geology, or of its history of poor organic accumulation in places where vegetation has long been sparse.

Cape Norman

But even here, plants manage to grow …

Cape Norman

Barrens Willow - Salix jejuna - Cape Norman

In general, precipitation tends to run off quickly … or just drain away, downwards, through the substrate …

carrying unconsolidated nutrients with it.

Port au Choix

Even so, some species, like this buttercup, seem to need such changing conditions!

Oval-leaf Spearwort – Ranunculus flammula var. ovalis – Port au Choix

As you have already seen, plants of the barrens have all kinds of survival tricks

Arctic Bladderpod - Lesquerella arctica – Burnt Cape

LONG ROOT SYSTEMS are critical in accessing scarce moisture and nutrients from a very wide area of soil

Moss Campion – Silene acaulis

Daubenmire (1941)

EVERGREEN LEAVES conserve hard-won and costly resources that would otherwise be lost, and have to be regenerated every year …

Hollyfern - Polystichum lonchitis – Burnt Cape

….and, as long as evergreen plants stays relatively green throughout the year, photosynthesis can take place, on warm days, in any season, effectively lengthening the plant’s growing season

Trailing Juniper – Juniperus horizontalis – Port au Choix

In the limestone barrens, the chemistry of calcium adds to the challenge

This saxifrage secretes excess lime from the edges of its leaves

Encrusted Saxifrage - Saxifraga paniculata – Burnt Cape

A major advantage of living on the barrens – is a lack of competition!

Dwarf Hawk’s Beard – Crepis nana – Burnt Cape

Many barrens species, such as Long’s Braya, actually thrive in disturbed areas where nothing else tends to grow

Yankee Point

But, in general, the plants of the barrens live on a razor’s edge

Burnt Cape

… with the rarer ones just making it …

Alpine Milkvetch – Astragalus alpinus var. alpinus – Burnt Cape

… and some others doing much better

Balsam Ragwort – Packera paupercula var. balsamitae – Indian River

… But, we really don’t know what’s ahead for them

Peter Scott

We might guess … but we really don’t know.

… will climate change help Long’s Braya … but hinder Fernald’s Braya?

… or vice-versa?

… or neither!

Will humans and nature eventually find ways happily co-exist?

It would be nice!

One thing is for sure … Even as tourists arrive in increasing numbers …

Cape Norman

… and humans in general continue to expand their influence

Heavy equipment re-arranging the Romaines River floodplain, August 1, 2006 !

We still have much to learn

Boat Harbour

Crab Spider on Yellow Lady Slipper – Burnt Cape

… End

… any many discoveries to make!