succession

Cyathea medullaris (Cyatheaceae) is a frequent pioneer of disturbed areas (e.g. landslides) or edge environments, sometimes forming near continuous canopies. We test the hypothesis that colonisation by this species as a pioneer alters the seedling assemblage to favour more shade-tolerant broadleaved trees than that beneath another common native pioneer (Kunzea robusta, Myrtaceae) in the same landscapes. We compared vegetation and abiotic characteristics of 166 sites across the Auckland region where C. medullaris or K.

Pinus contorta is a widespread and ecologically damaging invasive tree in the southern hemisphere. Land managers want control methods that limit reinvasion by P. contorta and promote the recovery of native plant communities and ecosystem functions. Recovery of native vegetation may be slow if native seed supply is limited and/or introduced mammals destroy seeds and seedlings. We investigated how tree control method (felling or poisoning), seed addition, and exclusion of introduced mammals affected subsequent seedling establishment in montane stands of invasive P.

[First paragraph...]
The Hunua Range consists of approximately thirty square miles of dense mature rain forest and an equal area of scrub and second growth. It is situated nearly thirty miles south-east of Auckland City on the western edge of the Firth of Thames (Fig. 1.) The range comprises a group of deeply dissected, up-faulted blocks of Mesozoic greywacke. The upland region is sharply delimited from the rolling lowlands by four well-defined fault lines in the east, south and west. To the north the area dips gradually into the Tamaki Strait and the Papakura-Clevedon lowland.

The Canterbury Plains have lost most of their pre-Polynesian indigenous vegetation, primarily forest and shrubland. One of the few remaining areas is the 2.3 ha Eyrewell Scientific Reserve which consists mostly of low kānuka (Kunzea ericoides) forest and a small area of grassland. We assessed the Reserve vegetation using a combination of plots and transect surveys at different times of the year between 2001–2003. For comparison with the Reserve vegetation we also assessed plots in an adjacent grazed kānuka remnant, adjacent cultivated pasture and Eyrewell Forest, a pine plantation.

Major trends in forest successions following fires are identified for northern offshore islands of New Zealand. Data are from the author’s observations over several decades, and published descriptions. Islands studied extend from the Cavalli group in the north to the Aldermen group in the south. Their original vegetation was largely destroyed by human-induced fires. Successions that followed were dominated for several centuries by pohutukawa (Metrosideros excelsa) or, for a shorter time, by kanuka (Kunzea ericoides).

We describe the colonisation of artificially created gaps in an alpine grassland dominated by Chionochloa pallens. Twelve years after their creation, the 50 cm _ 50 cm gaps supported a distinctive vegetation composed of a mixture of perennial forbs, grasses and mosses. Three species (Bryum sp., Epilobium alsinoides and Plantago novae-zelandiae) were recorded only in the gaps.

Native kanuka (Kunzea ericoides) and adventive gorse (Ulex europaeus) stands aged 10-14 years, and not grazed by domestic stock, were studied near Nelson, New Zealand. The aim was to determine their use by introduced small mammals, and native and adventive birds, and the effects of these animals on seed rain and seedling dynamics as factors influencing vegetation succession. Seed traps were established where they could catch only bird-dispersed or wind-blown seed, and seedling emergence and growth were monitored.

Previous studies have shown that indigenous beetle diversity reflects indigenous plant diversity in modified and remnant habitats. This study examines the indigenous: introduced relationship at a locality where degraded pasture has been progressively revegetated. Pitfall traps were used to collect beetles from three revegetated sites of different ages (5, 17 and 100 years) and in a coastal Muehlenbeckia habitat on Matiu- Somes Island (25 ha), Wellington Harbour, New Zealand. A total of 78 morphospecies were found over 12 months.

The Intermediate Disturbance Hypothesis [IDH] and the Gradual Climate Change Hypothesis [GCC] offer intuitively appealing, verbal non-equilibrium explanations to species coexistence in competitive communities, but so far they lack a solid theoretical background and a proper experimental methodology. To make them testable and comparable on a solid methodological basis, they should be formulated as well-defined non- equilibrium community dynamical models.

Predictions from three conceptual models of the dynamics of semi-arid vegetation (Clementsian succession, alternative stable states and annuation/pulse phenomena) are used to review the available evidence on changes in the vegetation of semi- arid lowland Central Otago, New Zealand. Evidence is presented from Central Otago that corresponds with Clementsian succession and with annuation/pulse phenomena, although there is so far no formal evidence of alternative stable states.