Botanist Newsletter
Issue No. 23, November 1998 to January 1999
Ecology Conference
In late November, the Australian and New Zealand Ecological Societies held a joint annual conference, in Dunedin. This covered a range of topics and a summary of a selection of them is appended. The full proceedings are available on request.
A number of people at the conference commented that they had heard that Christchurch City Council was doing some particularly good work in the area of restoration ecology. Those that had seen restoration projects in Christchurch seemed quite impressed.
There were a range of people at the conference, including staff from DoC, AgResearch, Landcare, CSIRO, FORST, Universities, Environmental Consultants, FRI, NSW Parks & Wildlife Service, HortResearch, Natural History NZ and Botanic Gardens.
Monitoring of Ecological Heritage Sites
Several site visits were made to EHS 5.01, which is the wetland at the Styx River mouth. The site is one of the best remaining wetlands and is a mixture of salt and fresh water wetland. Drier parts of the site are quite weedy, but the wetter areas are of very high quality.
A site visit was also made to the Southshore Spit, which is part of EHS 14.09. This area is a mixture of mainly exotic species (especially marram and lyme grass), but with scattered native components. There are also several patches of saltmarsh, which are predominantly native in composition.
Plant Photographs
The progress of the seasons meant that more plants were available to be photographed with flowers and fruits, so additional photos have been taken for the Streamside Planting Guide and the Waterway Weeds Guide.
A backlog of photos has also been filed. There are now 304 species with at least one photograph available.
Weeds
A waterway weeds database has been created to record weed species that are being reported by WorksOps staff. The database holds information on where the different species are and how they are being treated. The schedule for the work is also included. This will enable us to determine which species are a particular problem and the extent of the problem.
Urban Ecology
Species composition of some additional sites has been assessed for the urban ecology project. Some preliminary results were presented at the Ecology Conference in Dunedin.
Waterway Weed Guide.
Several field checks were made with WorksOps staff to ensure that the Weed Guide is working well. There was also a final meeting with the staff and certificates were presented to them to acknowledge their participation in all of the training and their efforts in the field.
Brooklands Lagoon
Several site visits have been made to investigate weeds at Brooklands Lagoon. These include pines, gorse, blackberry, sweet briar and grey willow. A relative new comer is Spanish heath, which has the potential to spread widely once it becomes established.
The work to control these problems needs to be targeted to be as effective as possible so a "weed plan" has been initiated.
Yellowing of plants was also investigated at Brooklands and enquiry’s made to MaF and Landcare. The best explanation seems to be that they are suffering from a combination of factors including the hot summer last year and low fertility conditions.
It was suspected that they may have been suffering from the "cabbage tree disease" (phytoplasma – see below) which is now known to occur in a number of other species. A botanist from Landcare however inspected the site and considers that phytoplasma is unlikely.
Phytoplasma
Phytoplasma refers to a group of bacteria, which are spread by sap-sucking insects. They have been found in a range of native species as well as some crop plants. Landcare and HortResearch are investigating phytoplasma and how to deal with it. At present phytoplasma is more of a problem in the North Island.
New Zealand Biodiversity Strategy
DoC has recently released this document. It includes discussion of what the appropriate biodiversity goal should be in New Zealand, ranging from doing nothing and our biodiversity continuing to decline, through various levels of effort to halting and/or reversing this trend.
The strategy deals both with ecosystems and natural habitats and with indigenous species.
Comments are due April 1999.
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