and habitat The kahikatea is endemic to the North, South, and Stewart Islands of New Zealand. It inhabits mostly lowland forests between 0 and 600m above sea level, though may in rare cases reach montane areas. It used to dominate a swamp forest type that now exists almost only on the South Westland region of the South Island. Kahikatea prefers flooded or alluvial soils with low levels of drainage, which in Westland occur from post glaciation events. Ecology Dispersal Under optimal circumstances a mature kahikatea can produce of fruit, equivalent to 4.5 million seeds, in a year. The fruit contains a special fleshy structure called a receptacle which helps attract birds such as the kererū, tūī, and bellbird, who then eat the fruit and disperse the seed elsewhere. One 2008 study in the New Zealand Journal of Ecology found a mean retention time of kahikatea seeds in kererū of 44.5 minutes. It was suggested in a 1989 study that the high water content of the receptacle may also help protect the seeds, which are vulnerable to drying out, from dry conditions. It may also serve as a storage vessel for water. The bluish seeds have very strong UV reflectance, which is visible to some species of birds. Epiphytes Kahikatea can support a vast number of non-parasitic plants that live in its branches, called epiphytes. One 2002 study identified between 90 and 100 species occurring on one mature tree. This included 49 vascular plants and over 50 non-vascular plants, which the authors identified as comparable to the number found on a Prumnopitys exigua in Bolivian cloud forest. Competition Intraspecific competition between kahikatea trees was found in a 1999 study to be an important factor in their survival and overall success, affecting both the rates of growth and of mortality. Older trees have a particularly large advantage over resources compared to newer ones, and also have higher growth rates. Following flooding or other natural events, the kahikatea has been found to require an open canopy in order to re-establish. Because of the consistency of these events in South Westland however, many forested areas don't progress beyond regaining kahikatea and rimu, as other species, such as kāmahi, need the environment to improve before they can return. Conservation Prior to the arrival of humans in New Zealand around 75% of the country was covered in trees, and kahikatea dominated its own and once widespread