light availability

Experimenting with methods to control Tradescantia fluminensis, an invasive weed of native forest remnants in New Zealand

Tradescantia fluminensis, commonly referred to as ‘tradescantia’, is an invasive weed of canopydepleted forest remnants. Previous research suggests that a reduction of tradescantia biomass to ~80 gm-2 (~40% cover) is compatible with native forest regeneration. I assessed herbicide application, hand weeding and artificial shading as methods for the control of tradescantia in two lowland podocarp/broad-leaved forest remnants in the lower North Island of New Zealand.

Kauri trees (Agathis australis) affect nutrient, water and light availability for their seedlings

Plants can change the soil that they grow on, for example by producing litter. If litter characteristics are such that their effect on the soil increases a plant's fitness, a positive feedback can develop between the plant and the soil. Several studies indicate that New Zealand kauri trees (Agathis australis) lower the availability of nutrients in the soil beneath their crown. Low nutrient availability would be positive for the survival of kauri seedlings as they are known to use nutrients more efficiently than angiosperm species.