Substantial areas of alpine tall tussock grasslands are being retired from grazing as part of Crown pastoral lease tenure review because of the perceived negative impact of grazing livestock. However, relatively little is known about the effect of sheep exclusion on these grasslands. We analysed data from five grazing exclosure plots over a 6-year period to examine the effect merino sheep have relative to hares and rabbits in alpine tall tussock grasslands used for summer grazing.
It is important, yet hard, to assess how much of the full range of New Zealand’s terrestrial natural ecosystems and biodiversity remains, and is protected from loss. Updated spatial datasets of land cover and protection allow a nation-wide consistent assessment of the loss and protection context of indigenous biodiversity components.
Long-term population monitoring has become an important tool for conservation management and indicator of environmental change. In many species nest counts are used as an index of population numbers. A pilot study using double-counts in Fiordland crested penguins (Eudyptes pachyrhynchus) found that up to 12% of nests had failed following the first count, raising concerns about search-related disturbance effects and the reliability of long-term monitoring data.
Restoration of urban forest remnants is an increasing activity worldwide, but the effects of restoration efforts on local wildlife in urban remnants remain poorly understood. Understanding the benefits of restoration can also be confounded because of difficulties in monitoring the abundance of representative species, or understanding their ecological requirements.
Monitoring is important in conservation management, essential for assessing population trends, making decisions and allocating resources. Artificial retreats can offer a reliable, low impact and efficient method for monitoring cryptic herpetofauna. Methods for monitoring artificial retreats vary between different conservation management programmes in New Zealand, however, and a deeper understanding of the causes of these variations would encourage greater standardisation and enable more reliable comparisons to be made across temporal and spatial scales.
Anthropogenic fire has transformed New Zealand’s vegetation. Small-scale historical Māori fires in the forests of Te Urewera National Park, North Island, initiated forest successions that were dominated early on by Kunzea ericoides (Myrtaceae), and later by Knightia excelsa (Proteaceae) and Weinmannia racemosa (Cunoniaceae). Previous work in these forests suggested that the more recent of these successions, initiated after the arrival of deer in the late 19th century, have failed to recover to pre-fire composition and structure.
Examination of the fish faunas of estuaries in New Zealand suggests that they have resident faunas of low diversity. However the estuaries serve as pathways in the migrations of a few marine fish species and a wide range of freshwater fish species. For this reason it is important that estuaries remain free from pollution and habitat modification
Estuaries are vulnerable, unstable areas sensitive to the impact of man, because they are at the interface of two contrasting environments in which the results of environmental changes induced by man are focused. This study presents data on the extent, character, status and on the number of surveys of New Zealand estuaries. The widest possible interpretation of the term estuary has been used so as to produce the most comprehensive list.
Deficiencies in knowledge of New Zealand plants are outlined, particularly with regard to conservation status and distribution. In an effective and integrated approach to the documentation and study of rare and endangered plants four aspects must be considered: documentation of individual taxa, provision of effective protective legislation, preservation of populations in the wild and in cultivation, and education of both the general public and botanists.
On three island groups off the northeast coast of New Zealand, fewer lizard species and markedly fewer individuals occurred on islands inhabited by Polynesian rats or kiore than on other islands without rats. Nocturnal, ground-dwelling lizards that forage in the open were most affected, which suggests that predation by kiore is the cause. The generally low densities and disjunct distributions of some lizards on the New Zealand mainland may have resulted from the introduction of kiore at least 600 years ago