Corokia cotoneaster

Abstract: When enclosures were contrasted with comparable control areas, the effects of grazing over a 17-year period on survival, establishment, and growth were determined for six montane shrub species—Discaria toumatou, Cassinia fulvida, Coprosma parviflora, Coprosma propinqua, Corokia cotoneaster, and Hymenanthera alpina One exclosure was in open grassland whereas a second encompassed the grassland-beech forest boundary The shrub populations in the exclosures generally showed greater height growth and lower recruitment rates, but no difference in survival rates, when compared with populations in control areas These trends do not apply to every species and site Cassinia fulvida in particular showed a dramatic decline in population size that is not related to grazing For most species, high survival rates, low height growth rates, and constant recruitment contribute to the relative stability of shrub populations

Abstract: Fruit flags are visual signals, other than fruits themselves, which attract frugivorous birds. In Corokia cotoneaster, an evergreen temperate New Zealand shrub, a scattering of leaves become coloured in autumn at the same time as the bird-dispersed fruits are mature; the leaves are similar to ripe fruit in shape and colour and may serve especially to attract birds to sparsely, fruiting bushes.

Abstract: The five fungi recorded in this paper have not been previously described from New Zealand. The fungi are: Corticolous Ascomycota: Nectria fuckeliana C.Booth on Pinus radiata D.Don. Caulicolous Ascomycota: Ophiovalsa betulae (L.Tulasne & C.Tulasne) Petrak on Betula pendula Roth. Caulicolous anamorphic fungi: Coryneum betulinum Schulzer on Betula pendula; Fusarium merismoides Corda on Acmena smithii (Poiret) Merrill & Perry, Corokia cotoneaster Raoul, Cotoneaster sp., Hoheria sp., Paulownia tomentosa (Thunberg) Steudel, Podocarpus totara Bennett ex D.Don, Prumnopitys ferruginea (Bennett ex D.Don) de Laubenfels, Sorbus aucuparia Linnaeus. Foliicolous anamorphic fungi: Leptomelanconium australiense B.Sutton on Eucalyptus ficifolia F.J.Mueller.

Abstract: Summary 1 An intriguing feature of the New Zealand flora is the high frequency of ‘divaricate’ shrubs and tree juveniles. These plants have numerous interlacing wide-angled branches with small leaves and no or few leaves in the outer canopy. They comprise 10% of native woody species, and have evolved in 18 different plant families. 2 We tested the hypothesis that the leaves of divaricate plants are sensitive to cold-induced photoinhibition, and that self-shading by outer branches reduces light intensities enough to prevent photodamage. In a field experiment, leaves of three divaricate species (Aristotelia fruticosa A. Cunn., Corokia cotoneaster Raoul and Coprosma propinqua Hook. f.) inside the north (sunny) side of the shrubs were exposed to one of three experimental treatments over winter: (i) control leaves which were not manipulated; (ii) exposed leaves which had their outer screen of branches pruned away leaving them open to full sun; or (iii) shaded leaves which were exposed by pruning, then sheltered from direct sunlight with shade cloth. 3 Experimental removal of the shielding branches in winter led to rapid ( 3 months) reductions in the maximum photosynthetic capacity (Amax) and photochemical efficiency (dark adapted Fv/Fm) in exposed leaves, but not in shaded leaves. Full recovery of photosynthetic capacity and photochemical efficiency was displayed by Coprosma propinqua, but very little capacity for recovery was displayed by Aristotelia fruticosa or Corokia cotoneaster. 4 When the effects of self-shading and photoinhibition were combined, control leaves photosynthesized faster than exposed leaves at all ambient irradiances in A. fruticosa, and in bright light (> 500 µmol m−2 s−1) in C. cotoneaster. 5 Our data show that by shielding their leaves within an outer screen of branches, the three divaricate species studied reduce photoinhibition of photosynthesis. We contend that this architectural self-shading in divaricate plants maximizes potential carbon fixation by minimizing photoinhibition.