Nikau

Abstract: Inflorescence and seed production was traced over seven consecutive years for the nikau palm, Rhopalostylis sapida, growing in temperate forests of northern New Zealand. Palms reach reproductive maturity when stems exceed a height of about 2.2 m, have about 60 frond scars, and are estimated to be approximately 90 years of age. However, inflorescences on young-mature palms usually aborted, and seed set was low for palms <3 m in height. Both the frequency of fruiting and the size of annual seed crops increased with increasing palm height to a maximum in the 6-8 m height class. However, the pattern of seed production in relation to number of frond scars (a better index of age) suggested declining seed production in old palms. Seed production varied up to three-fold between years and between sites. Seed production palm-1 yr-1 correlated positively with rates of frond fall (= frond production), inflorescences palm-1, and seeds inflorescence-1. Reproductive effort rarely exceeded 50%, possibly because ...

Abstract: This study records the Diptera fauna (excluding Culicidae) breeding in phytotelmata in the Auckland and Wellington regions of New Zealand, particularly in native forest habitats. Diptera larvae were relatively abundant in the leaf axils of the native epiphyte Collospermum hastatum, and in the fallen leaves of the native nikau palm Rhypalostylis sapida. Chironomidae and Tipulidae were the most common families collected, but larvae of Anisopodidae, Ceratopogonidae, Empididae, Psychodidae, and Syrphidae were also present.

Abstract: The hypothesis that stemflow is important in contributing to the nutrient requirements of nikau palm Rhopalostylis sapida individuals is examined. Stemflow directs many times more sodium, potassium, calcium and magnesium to the base of the palm than is required for annual net production. There are three sources for nutrients found in stemflow: (1) atmospheric inputs (wet and dry deposition); (2) foliar leaching; and (3) alien litter leaching and decomposition. Sources I and 3 together, representing nutrient input, contribute substantially more nutrients than are required for net annual production in mature individuals.

Abstract: Estimates of age, seed production and the pattern of biomass allocation are presented for New Zealand's only native palm species Rhopalostylis sapida. The age at which palms show above-ground stem development is uncertain, but appears to be in the vicinity of 40–50 years. Palms showing above-ground stems shed two fronds per year, on average. By counting the number of frond scars an approximate age can be determined. Seed production increases continuously with size (and age) for palms which exceed a maturity threshold determined by stem height. Although the percentage of total plant biomass represented by reproductive structures is low, seeds may account for over 50% of nikau palm net production in a year.