Pattern and process of vegetation change (succession) in recent volcanic landscapes of New Zealand and Hawaii

Volcanic activity (including lava flows, debris flows and tephra eruptions) is a regular feature of many landscapes of the North Island of New Zealand and the Hawaiian archipelago. Over the last 35 years, we have been using a combination of the chronosequence and direct monitoring methodologies (Clarkson 1998; Walker et al. 2010) to research the pattern and process of vegetation change (succession) in these landscapes. The following account summarizes pattern and process from our main study sites: Whakaari (White Island), Rangitoto Island, Mt Tarawera, Mt Ngauruhoe, Mt Ruapehu, and Mt Taranaki in New Zealand and Mauna Loa in Hawaii. The main focus of this account is forest development following significant eruptions

Evaluation of the Hamilton City Council plants for Gullies programme

This evaluation found that the Hamilton City Council Plants for Gullies programme is successfully facilitating the restoration and enhancement of Hamilton City gullies by private gully owners. The mean number of native species in surveyed gullies was 2.1 in non-restored sites and 18.4 in restored sites. While the mean number of invasive species was 4.1 in non-restored sites to 2.6 in restored sites. This quantitative measure is a valuable indication of the ecosystem gains for Hamilton City. Hamilton gully owners are very satisfied with the Plants for Gullies programme; the mean satisfaction rating was 8.9 out of 10. These residents dedicate significant time and energy to restoring their gully sections; the mean time contribution of survey participants was 10.3 hours per month. Gully owners were found to be utilising knowledge acquired through participation in the programme to add valuable diversity to their gully ecosystems. This was repeatedly demonstrated by programme participants not only reintroducing the native plants supplied by the programme but also adding large quantities of privately-sourced plants. This investigation found that the Plants for Gullies and Gully Restoration programmes are effective in communicating key ecological restoration concepts. This was reflected by gully owner prioritisation of eco-sourcing, biodiversity and weed control as considerations in their restoration projects. The Gully Restoration Guide was found to be the most valuable component of the programme’s educational tools. However, it is recommended that this resource is updated to support the many gully owners who require information for advanced stages of ecological restoration. In summary, the Plants for Gullies programme is successfully delivering gully restoration assistance and advice to gully owners, which is resulting in significant improvements to Hamilton City’s gully systems. The programme is valued by all who are involved and could be recommended to other New Zealand cities as an effective model for environmental restoration and community engagement

Indigenous vegetation types of Hamilton Ecological District

The following descriptions of indigenous vegetation types and lists of the most characteristic species have been compiled for the major landform units of the Hamilton Ecological District, which lies within the Waikato Ecological Region (McEwen 1987). The boundaries of the Hamilton Ecological District correspond approximately to those of the Hamilton basin, with the addition of parts of hills and foothills at the margins of the basin. The vegetation descriptions and species lists are based on knowledge of the flora of vegetation remnants in the ecological district, historical records (e.g., Gudex 1954), and extrapolation of data from other North Island sites with similar environmental profiles

Macrofossils and pollen representing forests of the pre-Taupo volcanic eruption (c. 1850 yr BP) era at Pureora and Benneydale, central North Island, New Zealand.

Micro- and macrofossil data from the remains of forests overwhelmed and buried at Pureora and Benneydale during the Taupo eruption (c. 1850 conventional radiocarbon yr BP) were compared. Classification of relative abundance data separated the techniques, rather than the locations, because the two primary clusters comprised pollen and litter/wood. This indicates that the pollen:litter/wood within-site comparisons (Pureora and Benneydale are 20 km apart) are not reliable. Plant macrofossils represented mainly local vegetation, while pollen assemblages represented a combination of local and regional vegetation. However, using ranked abundance and presence/absence data, both macrofossils and pollen at Pureora and Benneydale indicated conifer/broadleaved forest, of similar forest type and species composition at each site. This suggests that the forests destroyed by the eruption were typical of mid-altitude west Taupo forests, and that either data set (pollen or macrofossils) would have been adequate for regional forest interpretation. The representation of c. 1850 yr BP pollen from the known buried forest taxa was generally consistent with trends determined by modern comparisons between pollen and their source vegetation, but with a few exceptions. A pollen profile from between the Mamaku Tephra (c. 7250 yr BP) and the Taupo Ignimbrite indicated that the Benneydale forest had been markedly different in species dominance compared with the forest that was destroyed during the Taupo eruption. These differences probably reflect changes in drainage, and improvements in climate and/or soil fertility over the middle Holocene

Walk alongside: co-designing social initiatives with people experiencing vulnerabilities

The new VCOSS report, Walk alongside: Co-designing social initiatives with people experiencing vulnerabilities, invites people to challenge their thinking about social problems and the people affected by them, as well as the way government and the community sector works with them. It encourages us to genuinely connect with people experiencing vulnerabilities so as to understand their world, their aspirations and the solutions that will work best for them. The report describes the value of co-design: a ‘ground-up’ approach to service design that begins by asking people what their needs are, and then exploring possible solutions with them. It is characterised by the pursuit of social transformation, and focuses on positive goals of growth, wellbeing and social cohesion. Critical to this approach are the mentalities and mindsets that underlie a co-design practitioner’s thinking. The report describes a co-designer as being open and responsive to new insights, reflective about their own assumptions and holding belief in the creative potential of the people they are working with

Effect of Coriaria arborea on seed banks during primary succession on Mt Tarawera, New Zealand

An experiment was conducted over two years to investigate the effect of Coriaria arborea, a native nitrogen-fixing shrub, on soil seed banks at sites representing a post-volcanic successional sequence on Mt Tarawera, New Zealand. The sites ranged from bare volcanic ash and lapilli substrate, through low-growing pre-Coriaria vegetation, to dense stands of Coriaria scrub. Soils (to a depth of 50 mm) under recently established Coriaria and older stands had more seedlings (1096 and 1585 seedlings 0.4 m-2, respectively) and species (37 and 45 species 0.4 m-2, respectively) emerge than where there was no Coriaria (243-320 seedlings 0.4 m-2, 14-25 species 0.4 m-2) and were the only soils with Coriaria seedlings. In total, 3488 seedlings representing 63 taxa were recorded. Seeds were still germinating after 24 months but rates declined markedly in the second year. For example, Coriaria reached a germination peak at 8 weeks but continued to germinate sporadically over the 2-year period. Tree species present in young forest within 0.5 km of the sites were absent. Establishment of Coriaria greatly accelerated an underlying trend of gradually increasing abundance and diversity of seeds in the soil with vegetation age. Adventive, wind-dispersed, and annual species were over-represented in the seed banks compared with the regional evergreen forest-dominated flora. These proportions are expected to decline as succession to forest gradually occurs