Botanist Newsletter

Issue No. 28, October 1999 to February 2000

Ecological Heritage Sites

Monitoring of these sites is ongoing as part of the requirements of the Resource Management Act. EHS 1.31 (McLeans Island Rd) was recently visited. Unlike most of the other dry plains grassland sites, some regeneration of kowhai was seen (Fig. 1, 2). Few seedlings have been seen on other similar sites, presumably because of grazing by sheep and/or rabbits. A brochure about Ecological Heritage Sites for the public is also underway.

Black Orchid in Little Hagley Park

Colin Meurk has found a black orchid (Gastrodia cunninghamii) growing along the Avon riverbank (Fig. 3, 4). This plant typically grows in beech forests, but in this case it is living under sedges and coprosma.

Grazing of the Port Hills Grasslands

A meeting between DoC and several Parks staff clarified how to proceed in arranging grazing licences for the various types of reserves, depending on how they are held. A grazing strategy is being written and will be used as the basis for discussion about the best methods and levels of grazing. This will then be presented to council for their approval, before advertising for licensees begins. DoC approval of licences will be required for some of the reserves.

Scarborough Hill Reserve

Scarborough Hill has been investigated to determine the fences required and the conditions that will need to be specified in a grazing licence for this site. Scarborough Hill also has several significant plant pests, including bur daisy (Calotis lappulacea, Fig. 5) and nasella tussock (Nassella trichotoma).

The adjacent Rapanui Bush has bachharis (Baccharis halimifolia). These are all plant pests under the Regional Pest Management Strategy. The bur daisy and baccharis are total control plants (strategy requires eradication of plants and eventually of seed bank). Nassella is a progressive control plant (strategy requires significant reduction in source plants).

Mouse-ear hawkweed

A site visit to Bottle Lake Forest turned up some mouse-ear hawkweed (Hieracium pilosella, Fig. 6). Hawkweed is a significant weed, particularly in South Island high country grasslands. A forthcoming site visit will check how widespread it is and remove plants. Early detection increases the chances of controlling this species before it becomes a significant problem.

Clearwater Resort

A site visit to the Clearwater site produced quite a good list of native species along the river banks, including rushes, sedges and ferns. Of particular note was plentiful Potamogeton cheesemanii in the stream and quite a large patch of Myriophyllum propinquum (Fig. 8). The exotic 'fox sedge' (Carex vulpinoidea) was also seen - this is a new record for Canterbury (Fig. 7).

Weeds & Wetlands

We had several interesting overseas visitors late last year. Margo O'Byrne, from Perth, discussed weed control and public participation. Margo noted that volunteers both benefited from and appreciated training. Bill Mitsh, from the U.S. had a whirlwind tour of a few of Christchurch's wetlands and commented on how much greater our weed problems are than in many other countries.

Waimakariri River Corridor

Several field trips along the southern Waimakariri River bank to look for wetlands, with Canterbury Regional Council, have turned up quite a few significant sites. Several interesting grassland sites were also found. Of particular note was the discovery of some dwarf woodrush (Luzula celata), a native woodrush that is quite uncommon in Canterbury (Fig. 9). A subsequent detailed search (by Landcare staff) found quite a significant population in the area.

Bromley Marsh

A botanical assessment was made of a wetland which is located in Bromley, off Francella Road. This turf marsh contains a good range of species, including significant amounts of Myriophyllum propinquum and silverweed (Potentilla anserinoides, Fig. 10). This type of wetland is unusual because it is dominated by low turf species. It is more typical in Christchurch for similar sites to be dominated by taller rush/sedge associations. The existing grazing regime is helping to maintain this particular plant association.

Waterway Weed Poster

A weed poster is underway for the public that will provide pictures and descriptions of many waterway weeds. The poster will use a lot of the work that has already gone into the Waterway Maintenance Plant Guide, but will be significantly cheaper to produce. This project is at the formatting stage.

Bankside Scientific Reserve

DoC kindly gave us permission to visit Bankside Scientific Reserve. The city council is particularly interested in this remnant of dry plains grassland shrubland as it is one of the few examples left. It is similar to some of the vegetation in the McLeans grassland area, only with a greater shrub component (mainly kanuka) (Fig. 11, 12).

Bowenvale Valley

A field trip was held for a range of city council staff to discuss some of the issues on the Port Hills. This area is Project Area 1 in the Waterways and Wetlands Asset Management Plan. The decision was made to initially concentrate effort on Bowenvale Valley.

Styx River

An investigation into the aquatic ecology of the Styx River is being coordinated by Woodward-Clyde. Initially this will concentrate on assembling existing information rather than collecting new material.

Restoration and Maintenance Database

A new database has been set up for the Waterways and Wetlands team. The database enable the team to record details describing each site and its location as well as noting who is involved. This assists in managing all of the projects and in their reporting. Currently there are 422 restoration and maintenance projects recorded.

Maps

Many of the maps produced recently have taken advantage of the aerial photographs that we now have available for much of the city. Maps were produced recently for the following purposes:

• To assist in the planning and acquisition of open space - a citywide map shaded to show the different size classes of land parcels (Fig. 14).
• For a Parks Area Plan to circulate to residents, for comment on proposed park developments and expenditure - parks in the Heathcote ward.
• In support of an application for funding - environmental education sites within Christchurch City.
• To accompany a report to council - areas where restriction or prohibition of dogs is proposed (around the coast and estuary).
• For ranger staff on the Port Hills - the overlap between Ecological Heritage Sites and reserves.
• For CRC staff to use in their pest control operations - aerials of the Port hills.
  To assist parks staff in maintaining the ~3100 trees - South Hagley trees.
• To show the placement of graves and enable better directions to be given to the public - aerials of each of the cemeteries.
• To enable planning to take into account a wide range of factors - Project Areas 1 & 10 of the Waterways and Wetlands Asset Management Plan, showing existing natural areas information.

New Map Layers

Several new map layers are now available to city council staff:

• Digital version of the 1:50 000 topographical maps, covering all of Canterbury Region (Fig. 15)
• Soil stability on the Port Hills (supplied by Landcare/CRC)
• Sub-catchment boundaries for the Heathcote catchment

New Books

The latest additions to the botanical library, available to city council staff to borrow, are:

(1999) Reserves Act Guide. Local Government New Zealand & Department of Conservation. This guide summarises the administration of the Reserves Act in a 'user-friendly' manner.

Beever J (1991) Dictionary of Maori Plant Names. Auckland Botanical Society. This book lists botanical names and their equivalent maori names.

Dopson SR, de Lange PJ, Ogle CC, Rance BD, Courtney SP, Molloy J (1999) The Conservation Requirements of New Zealand's Nationally Threatened Vascular Plants. Threatened Species Occasional Publication No. 13. DoC. Provides details for 223 threatened plants about aspects such as threats, conservation work to date, priorities, research and management. There is also analysis of this data.

Edgar E, Connor HE (1999) Flora of New Zealand Volume V: Grasses. Manaaki Whenua Press (Fig. 16). This flora completes the vascular flora of New Zealand. It details the identification of native and naturalised grasses, as well as providing information on aspects such as their distribution and ecology.

Hall I, Buchanan P, Yun W, Cole A (1998) Edible and Poisonous Mushrooms: an introduction. Crop & Food Research. Includes pictures and information on a variety of wild and cultivated mushrooms.

Moore SC (1997) A Photographic Guide to the Freshwater Invertebrates in New Zealand. Otago Regional Council. A guide to identifying the major invertebrate groups using coloured pictures. Information about what each group indicates regarding the health of the waterbody is also included.

Porteus T (1993) Native Forest Restoration. QEII National Trust. This booklet covers some of the problems and issues likely to be encountered in restoring native forest. It includes practical information on subjects such as animal and weed control, plant propagation and planting. It also covers techniques to use in particular conditions (e.g. planting under gorse or planting in grassland).

Sykes W, Webb C, Brooke PA (1988) Poisonous Plants Poster. Manaaki Whenua Press. The poster describes and illustrates 34 poisonous species, and which parts are poisonous. It is accompanied by a more detailed list of South Island plants that are poisonous to children.

Egeria

The attempt to eradicate the aquatic weed egeria is continuing. We are also trying to increase the public awareness of the problem and the importance of cleaning their boats between sites (Fig. 16).