Five plant species native to the Gulf Islands in rapid decline because of predator suppression

2018 May 15 Camassia leichtlinii inside the north upper exclosure, Mount Maxwell Ecological Reserve, Hwmet’utsun Conservation Area, Salt Spring Island

Five plant species native to Salt Spring Island have been in rapid decline in recent decades because of historically elevated populations of deer, Odocoileus hemionus columbianus, largely because of predator suppression:
both species of native camas, Camassia leichtlinii and C. quamash;

Menzies larkspur, Delphinium menziesii;

common wooly sunflower, Eriophyllum lanatum; and

springbank clover, Trifolium wormskioldii.

2018 May 15 Menzies larkspur, Delphinium menziesii, P5150151 north upper exclosure, Mount Maxwell Ecological Reserve, Hwmet’utsun Conservation Area, Salt Spring Island

Today, these once abundant populations are often reduced on the larger Gulf Islands, areas with large deer populations, to the following sites:

well-fenced exclosures such as the three small areas in Mount Maxwell Ecological Reserve constructed in the years following its 2001 expansion);

rocky cliffs difficult for deer to reach; and

some tiny strips near busy roads and urban areas that deer avoid (including Grace Islet near Ganges).

2018 May 15 springbank clover, Trifolium wormskioldii, cliff Mt Maxwell Ecological Reserve and also in the N upper exclosure, Hwmet’utsun Conservation Area, Salt Spring Island, Salt Spring Island

The two large predator species, that have primary ecological relationships with populations of black-tailed deer were wolf, Canis lupus, and cougar, Puma concolor. In the last fifty years, outlier wolves have had only a sporadic presence on some of the smaller Gulf Islands (recently Chatham Islands and earlier Saturna) with the last large pack on central Salt Spring Island exterminated in the 1930s. There are wolf packs not far from Salt Spring Island, above the Cowichan Valley. But those packs are separated from the Gulf Islands by the Island Highway and increased travel barriers from suburbanization. A small number of cougars survive at higher elevations on Salt Spring Island but may be isolated and quite possibly in-bred. Migration corridors away from Salt Spring Island have not been determined but may include the Stony Hill and Mount Tzouhalem just across Sansum Narrows.

2018 May 15 common wooly sunflower, Eriophyllum lanatum P5150107 central upper exclosure Mount Maxwell Ecological Reserve, Hwmet’utsun Conservation Area, Salt Spring Island

 

2018 May 15 Camassia quamash P5150115, central upper exclosure Mount Maxwell Ecological Reserve, Hwmet’utsun Conservation Area, Salt Spring Island

 

blooming chokecherry trees, SC̸ET̸EṈILĆ [SENĆOŦEN], tuluµulhp [HUL’Q’UMI’NUM’], Prunus virginiana, Hwmet’utsun Conservation Area, Salt Spring Island

blooming chokecherry trees, Hwmet’utsun 2018 May 3

One of the loveliest of the relatively uncommon groves of chokecherry, Prunus virginiana, the only tree (and fruit tree) that is native to every province and territory in Canada (and the northern half of the continental USA). While small clumps of chokecherry trees are common across Canada, they are uncommon on the BC Coast. The other part of the West Coast where this species occurs is in Mendocino Country in Northern California. This grove in Mount Maxwell Ecological Reserve in the Hwmet’utsun Conservation Area on Salt Spring Island, has relatively old trees, verging on more than a century, along with large fallen trees, and saplings.

The bark is the source of the medicinal in traditional cherry cough drops and the berries are good to eat (for both humans and crows). While I have seen no other large groves such as this, there are many young trees on Salt Spring Island most likely because the species is poisonous to deer which here is often in relatively high numbers because of predator suppression.

trunk of older chokecherry tree in exceptional grove in Hwmet’utsun Conservation Area, Salt Spring Island 2018 May 3

This grove of chokecherries is in a landscape with archaeological sites going back well over 5,000 years and Salish (Cowichan Tribes) presence continuous until well into the 20th Century and ongoing harvesting of some food resources. The sites with the chokecherry trees have signs of historic food processing.

The lines of holes in the bark are from woodpeckers and are common for the older trees.

younger trees in exceptional West Coast grove of chokecherry, Hwmet’utsun Conservation Area 2018 May 8

flowers of Pacific dogwood, kwit-xulhp [Cowichan – Island Hul’q’umi’num’], Cornus nuttallii, in Mount Maxwell Ecological Reserve, Humet’utsun conservation area, Salt Spring Island

2018 May 3 Pacific dogwood – Hwmet’utsun – photograph by Gordon Brent Brochu-Ingram

 

2018 May 3 Pacific dogwood – Hwmet’utsun – photograph by Gordon Brent Brochu-Ingram
2018 May 3 Pacific dogwood – Hwmet’utsun – photograph by Gordon Brent Brochu-Ingram

the apple gene pool at KEXMIN field station

modern apple cultivar nearly in bloom, KEXMIN field station 2018 May 3 photograph by Gordon Brent Brochu-Ingram

While the focus at KEXMIN field station is often on wild native species, especially food plants stewarded by the Salish, the Eurasian apple cultivar, Malus pumila, such as the one recently planted here, is in the primary gene pool of Pacific crabapple, Malus fusca, the native apple of North-western North America (that continues to thrive from California, along the Pacific, to north of Japan). In contrast to the red in the buds of this European cultivar, those of the Pacific crabapple are a uniform ivory with not even hints of pink.

While we are engaged in propagation of Pacific crabapple, scores of individuals and a number of ‘groves’ thrive nearby.

 

blossoms of Pacific crabapple, Malus fusca, Ruckle Provincial Park 2018 May 1 Gordon Brent Brochu-Ingram