Forked three-awned grass (Aristida basiramea) COSEWIC assessment and status report: chapter 5

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Habitat

Habitat Requirements

In the US, the species occurs in rare habitats such as pine barrens, but can also tend to more weedy habitats, e.g. its citation in the Flora of the Great Plains (McGregor et al., 1986) as “roadsides, pastures and waste ground”. Allred (2001) notes that the presence of Aristida frequently indicates soil disturbance or abuse. In Ontario and Quebec it appears to be restricted to dry, open sand barrens, which occur on low, sand ridges or dunes, located on post-glacial shorelines. The fact that the four Ontario populations are all located in north Simcoe County and adjacent Beausoleil Island, is probably a result of the preponderance of intact old shorelines through this area. Reznicek (pers. comm. 2001) has concluded that A. basiramea “seems certain to be a hypsithermal relict of post-glacial lake stages.” The pH of all four sites would be acidic, although actual analyses of soil samples does not appear to have been done.

The habitat for A. basiramea would be termed as early successional, although with disturbance, i.e. fire or drought, it would be maintained over long periods of time. However, with suppression of fire and urban development throughout southern Ontario and southern Quebec over the past one hundred years, this sand barren habitat has been greatly reduced, and exists today in very small, highly fragmented remnants. Large tracts of natural land on the north end of the Penetang Peninsula east of Awenda Provincial Park for example are dominated by closed canopy forests, with sandy openings being extremely rare.

The predominant species at the Ontario and Quebec stations is Danthonia spicata, with other prevalent associates being: Rumex acetosella, Agrostis gigantea, Polytrichum sp., Panicum implicatum, Poa compressa, Solidago nemoralis, Carex merritt-fernaldii, Rubus alleghaniensis, Agropyron repens, Cyperus houghtonii, and Cyperus lupulinus subsp. macilentus.

The Christian Island and Cazaville populations are the most populous of the five stations, both supporting greater than ten thousand plants, and are likely critical to the long-term survival of the species. To the south and west of this station there appears to be potential habitat for the species. There could very well be high quality sand barrens elsewhere on the island that the author did not have time to survey for the current report. With respect to the Cazaville station, the site has been visited three times in the past two years, and the surveyors do not expect to find many other subpopulations (Coursol, pers. comm. 2002).

Trends

The Macey Lake population was noted by Reznicek in 1975 as “widely scattered & sometimes frequent in the most open areas”, while the Christian Island population was noted in 1981, also by Reznicek, as “frequent (60 – 80? plants), locally a dominant in areas of more or less bare sand”.

While the north end of the Penetang peninsula is developing rather quickly, similar sand barren communities still exist at Christian Island, as well as sites on the mainland east of Awenda Provincial Park.

There has been a significant reduction in these sand barren communities in southern Ontario and southern Quebec over the past 100 years, the result of forest succession and concurrent suppression of natural periodic fire, clearing of land for agriculture, large scale establishment of conifer plantations, increasing use of open shoreline areas (old & new) for housing and recreation (including ATVs), and extraction of sand for commercial uses.

This rate of change has accelerated in Simcoe County in the past few years, with Barrie (110,000 pop.) consistently being accorded status as “the fastest growing municipality in the Country”, often followed by Wasaga Beach (16,000 pop.). Outside of these two towns, estate sprawl is very common in north Simcoe County, and Great Lakes shorelines are rapidly developing. Most sand barren habitats in Simcoe County are not protected, and the current level of habitat protection is inadequate to ensure the long-term survival of Aristida basiramea.

Protection/ownership

Of the five stations, only one, Beausoleil Island, is currently offered any significant level of protection. However, at the National Park the species is not captured within protective-level zoning.

ChristianIsland – The population of A. basiramea is on the Beausoleil First Nations Reserve, on land retained in ownership by the Band Council. The Band is contemplating development opportunities for this site (Kopagog, pers comm. 2001).

Christian Island is a regionally significant ANSI. These are presently not accorded status under the Planning Act in Ontario, and land use decisions regarding significant natural areas on Reserve lands, lie of course, with the individual Band Councils.

MaceyLake – The population is located on a privately owned site where for several years the previous owner operated a small commercial peat extraction operation, using the south end of the bog, with the adjacent shoreline flats and sand hills serving as his land base for processing and shipping. The population of A. basiramea appears to be thriving in the areas of the site disturbed by the peat operation, where work was discontinued in 1995.

The private property on which the Aristida basiramea occurs is very proximal to Awenda Provincial Park. The presence of provincial ANSI, provincial wetland, and occurrence of an S1 species on site, combined with the ability to acquire and ‘add’ the property to Awenda Provincial Park, has prompted interest in possible acquisition for conservation purposes. The site was identified as high priority for purchase in the 1990 Park Management Plan and in fact it was included in the original park boundary for the Awenda in the 1970s (Tully pers. comm. 2001), prior to any peat mining having occurred. The effort at that time to expropriate by the Ministry was believed to actually expedite the peat mining. In the early 1990s the Park was approached by the owners to explore possible purchase, but the asking price was deemed too high. In 1998 Tim Tully approached the Nature Conservancy of Canada (NCC), but the property was not on the market at that time so NCC did not pursue. Macey Lake is the #2 priority identified by Awenda Park for acquisition and north Tiny Township is now on the NCC’s priority list for acquisition. Macey Lake remains a highly favourable site for conservation acquisition, and lends itself well to a joint NCC/OMNR initiative, with Awenda Provincial Park assuming management responsibilities.

The population of A. basiramea is adjacent to, but within the Macey Lake Bog Provincial Area of Natural and Scientific Interest (ANSI), the boundary of which encompasses the wetland. This Aristida basiramea station is also within 120 metres of the Macey Lake Bog Provincially Significant Wetland, and such wetlands are also treated as Environmental Protection One in the official plan. The Tiny Township Official Plan states that no development shall be permitted on these 120 metre adjacent lands unless an Environmental Impact Study is completed in accordance with Section C6 of the official plan and approved by Council, subject to comments of the appropriate agencies.

Also of note is the fact that the Tiny Township Official Plan recognizes Threatened and Endangered species as designated by COSEWIC and OMNR, and accords the significant portions of the habitat of such species as Environmental Protection One as well. This is the highest level of protection within the official plan. Permitted uses on lands designated Environmental Protection are limited to conservation and passive recreational uses. No buildings or structures are permitted, nor is any site alteration permitted in this designation. Golf courses are not considered to be passive recreational use; however, nothing in the official plan is intended to limit the ability of agricultural uses to continue on lands designated as Environmental Protection One (The Planning Partnership, 2000).

Beausoleil Island – The station for A. basiramea at Beausoleil Island is not within a protective zone of the National Park, but rather is located in a recreational or administrative zone. The Park has no immediate plans to change anything at this site, and the Park Superintendent and Park Ecologist have been alerted to the fact that they have an extremely rare plant behind their Visitor Centre. They have also expressed willingness to manage for the species if required, including prescribed burning (pers. comm. Upton, 2001).

Anten Mills – The entire lot within which the A. basiramea is supported was sold in 2001 by the owner to a developer who has obtained the necessary approvals to develop an 87-lot subdivision. The majority of the population occurs along the crest of the Algonquin shoreline, where single family lots will be created. Fortunately, some of the Aristida population will be contained within a passive natural parkland to be retained by the developer, as requested by Springwater Township. The Township Planner has been informed of the significance and locations of the A. basiramea by the author of this report, and the author has been on-site with consultant for the developer, but the best case scenario in the face of this fully approved subdivision is likely a salvage operation. The author has proposed this to the developer and will be supervising a backhoe operator this spring to move plants from the main population at the top of bank, downslope and proximal to the subpopulations along the base of the shoreline.

Cazaville – All lands at this station are private, with likely more than one hundred owners over the extent of the occurrence. No landowner contact has been conducted. No industrial development is envisaged in this sector (Coursol, pers. comm. 2002).