THE WORLD CONFERENCE ON ECOLOGICAL RESTORATION

2005 The World Conference on Ecological Restoration 49
choices between measures within a limited area. One of this is a costs-effectiveness study, showing the
approach needed according to the EU Water Framework Directive. It’s concluded that there is not yet a
clear policy is using decision support systems in regional water management, nor in a set of standardised
instruments for preparing weighed decisions for wetland restoration.
Keywords: Environmental degradation, functions of water systems, priorities and selections in measures,
regional wetland restoration.
Assessing the success of restoration planting in Hamilton City, New Zealand
Clarkson B.D., B.D. Mackay
Centre for Biodiversity and Ecology Research. University of Waikato, Private Bag 3105, Hamilton, New Zealand
Hamilton City (New Zealand) is the focus of a concerted public and private effort to retrofit the City by restoring
and reconstructing indigenous ecosystems. To date some 187 ha of land or 2% of the City area is being actively
restored comprising 142 ha on public land and 45 ha on private land. In order to determine how successful
previous restoration plantings have been in achieving desired ecosystem states and to guide future
projects, research was undertaken on a range of restoration plantings within the City. Some 62 variable area
plots were measured to cover the range (chronosequence) of planting ages (0-30 years), maintenance treatments
(low vs high), and initial states (bare vs existing canopy) on gully slopes, the landform on which most of
the restoration planting in the City occurs. Data collected from 4 plots in natural regenerating forests within or
near the City were used as baselines to assess progress towards establishment of natural functioning ecosystems.
Results showed that it is comparatively easy to establish a low diversity indigenous forest canopy on
bared sites within 20 years, and by this stage, some early maturing canopy species will be starting to regenerate.
Indigenous ferns, including tree ferns, colonize the restored stands unaided. Although restored stand
basal areas are comparable with natural regenerating forests, the excessive use of well known pioneer plants
and the tendency for failure of early planted mid- and later successional species leads to stalling of forest development.
From 20 years on, the indigenous restoration plantings decline in indigenous species richness and
cover and there is an increase in exotic species colonization especially in canopy gaps. Amongst the colonizers
are several troublesome weeds (e.g., Japanese honeysuckle) with the potential to out compete indigenous
species. Because of isolation and lack of seed sources, the expected mid- and late-successional shrub and tree
species need to be introduced to the restored stands via enrichment planting or seeding. Most management
programmes fail to recognize this requirement and valuable progress is lost. The challenge now is to build the
lessons learned from this research into new and existing restoration planting programmes in the City.
Keywords: urban restoration, restoration planting, forest development.
Restoration of a cut-over peat bog in northern New Zealand
Clarkson B.R., C.H. Watts, L.A. Schipper
Landcare Research, Private Bag 3127, Hamilton, New Zealand
Torehape peat bog in northern North Island, New Zealand, is currently being mined for horticultural
peat. The miners are required to restore the area to original bog vegetation once the permitted depth of
peat has been removed. We established a restoration trial on the mined peat surface to determine the
best practical approach to restore vegetation cover. The trial involved combinations of water table, peat
cultivation techniques, nutrients (N and P), and seed additions (the heath shrub Leptospermum scoparium
[Myrtaceae] and the restiad Sporadanthus ferrugineus [Restionaceae]), characteristic of both early and
late successional stages of bog development. The most effective treatments were raised ‘islands’ of
processed peat seeded with small branches of Leptospermum laden with ripe capsules, which reached
100% vegetation cover within two years. The miners adapted this approach to restore a larger area (200
ha) of mined peat. We assessed the effectiveness of this upscaled approach by monitoring vegetation and
invertebrate recovery at intervals following island establishment, and comparing patterns and trends
with peatland buffer baselines. Results showed key peat-forming species such as Sporadanthus, Empodisma
minus (Restionaceae), and occasionally, Sphagnum, had established naturally within two years,
indicating the developing Leptospermum shrubland acts as a nurse for other bog plant species. As vegetation
cover and species richness increase, invertebrate composition and abundance become more similar
to that of the buffer. This simple low-cost approach speeds up peatland recovery and gives significant
biodiversity benefits.
Keywords: restoration, cut-over bog, vegetation, invertebrates, monitoring.