You are here: Tussock Grasslands MIS Site Contents Blue Tussock Grasslands Background management information Select from: Identification Habitat Other spp. present Vegetation history Management options Or return to communities indexes: || High altitude || Mid altitude || Low altitude || drylands || Management Information for Blue Tussock Grasslands || high altitude || influencing factors || grazing || buffering || weeds || vegetation succession || monitoring || Developing management options The majority of tussock grassland research has focussed on determining the vegetation history of the mountain lands, and how pastoral management practices have influenced vegetation succession patterns. Only recently has grassland research started to look at the issue of progressive successional changes occurring on retired land (i.e. what vegetation changes will take place when tussock grasslands are retired from grazing and burning). In addition, the majority of studies have focussed on determining the impacts of pastoral use on induced montane fescue tussock grasslands (Festuca novae-zealandiae), the most widespread type of short tussock grassland in the eastern parts of the Main Divide. There are many information gaps to be filled, some of which are currently addressed in the FRST-funded research programme "Improved Management Systems for Tussock Grasslands". For more information about this research programme and how to become involved, contact the programme leader Dr Ockie Bosch at boscho@landcare.cri.nz. In the meantime, the suggested management options have to draw on broad principles and "best guesses" by ecologists, or observations made by people who live and work in the tussock grasslands. Such "best guesses" may be appropriate in some situations, but not others. They will be updated as and when more information becomes available. High-altitude tussock grasslands High-altitude tussock grasslands generally require less active management than such communities at lower altitudes. High-altitude areas tend to be less modified, as the more extreme growing environment makes such areas less attractive for pastoral development. Short tussock grasslands at high altitude are an exception. Although some occur naturally in zones of natural disturbance such as avalanche paths, most of those occurring east of the Main Divide have been induced from tall tussock grasslands as a result of pastoral management, and may be further modified by weeds. Factors influencing the distribution and characteristics of tussock grasslands for more information on environmental gradients that determine the distribution of tussock grassland types, or the management factors that have influenced the characteristics of tussock grasslands. Vegetation change since human settlement if you want further information on a generalised model for vegetation change, east of the Main Divide. Evolution of a blue tussock (Poa colensoi) grassland Blue tussock grasslands have been induced from tall tussock grasslands, which have been repeatedly burnt and grazed. For Central Otago communities, Meurk (1982) postulates that following patch burning of the snow tussock grassland, sheep concentrate on the patch, preventing the snow tussocks from regenerating. A grazing tolerant blue tussock-herbfield results. With light grazing, alpine fescue tussocks, with Spaniards become established amongst the blue tussock sward. However, where wind erosion has taken place, the blue tussocks drop out, leaving an induced short tussock grassland dominated by alpine fescue tussock and Spaniards. Elsewhere where heavy rabbit browsing occurs, the blue tussock -herbfield is reduced to a bald cushion cover, with some blue tussock cover, which recovers when rabbits are controlled. Where repeated burning of snow tussocks has occurred, a mosaic of tall tussock remnants, interspersed with blue tussock-cushionfields, and blue tussock/ alpine fescue tussock/ Spaniard grasslands results. Maintaining a blue tussock grassland While individual tussocks would have always been present in snow tussock communities above the treeline, grasslands dominated by short tussock grasslands would have been induced by repeated burning and grazing of the snow tussock grassland. To stop snow tussocks or alpine shrubland species (where present) from out competing the blue tussock, active management will be necessary. At a conservation workshop held in June1996, some participants (ecologists and land managers) indicated that continued grazing of these induced grassland may be necessary to keep them there. However, the actual goal of wanting to maintain an alpine blue tussock was questioned by some participants.

Grazing

The relationship between an area managed for conservation purposes and its surrounding landscape is important. Ideally, the area should be surrounded by land, which will buffer it from external influences that may compromise its conservation values.

• act as a fire break, thereby protecting neighbouring land from wild fires occurring in dense tussock grasslands, or preventing controlled fires on pastoral land inadvertently burning an area managed for conservation;
• protect the area from inadvertent drift of fertiliser and/or seed from neighbouring land (during aerial application);
• help reduce the rate of spread of some weed species into the area, e.g. intensive grazing between a forest and an ungrazed tussock grassland helps reduce the establishment of wilding trees from that forest.

Weed control

Weed spread is less likely to be a problem at high altitudes, except where significant disturbance has taken place e.g. sheep camps, or at sites which are downwind of conifer stands (plantation or wilding forests). Periodic monitoring of the area is necessary to determine whether weed species are coming into the area, and whether they are reaching problem levels. An assessment of the feasibility of controlling the weeds will then have to be made.

for more specific information on weed control

Irrespective of whether managed for pastoral use, or soley for conservation purposes, many short tussock grasslands have a significant component of hawkweed. A large number of studies have been conducted to investigate the relationship between grazing management and rate of Hieracium spread, and associated trends on vegetation composition. However, no studies have focussed specifically on alpine fescue tussock grasslands.

Summary of study findings

Hieracium Management Information Module

Succession in short tussock grasslands in general

if you want general information on factors influencing vegetation succession (includes model for vegetation succession).

Native woody plant regeneration

The regeneration of native subalpine shrubland species is dependent on the seed source and presence of adult plants in the grassland.

Hares, rabbits, deer, goats or chamois may deplete alpine fescue grasslands if grazing pressure is too high.

The management guidelines suggested are based on the best available information, and are often only "best guesses". To ensure that the management practices are achieving the desired management goal, it is crucial that the vegetation condition and composition, weed status, and animal pests are monitored. Management may have to be changed in response to the findings of such on-going monitoring.

for more information on monitoring in tussock grasslands

• All references
• Short tussock grasslands
• Tall tussock grasslands
• Burning studies