Effects of vegetation structure on nutrient outflows from a montane tropical Forest Grassland mosaic

Changes in vegetation structure and composition can change soil erosion and the outflow of nutrients from an ecosystem.

We investigated sediment and nutrient outflow from 11 catchments with different land covers in the montane Nilgiris, a part of the Western Ghats biodiversity hotspot, India. Preliminary analysis suggests that invasion in this landscape increases sediment and nutrient outflow. Further analysis will shed light on how invasive plant species change these outflows in this landscape. 

Ammonia (NH3) is mainly released from agriculture and traffic and may have phytotoxic effects only at high concentrations. At levels below 50 µg m-3 acute effects are unlikely, but chronic responses may occur in nitrogen sensitive species.

While classical air pollutants are included in Air Quality guidelines and have been studied extensively, phytotoxic and chronic effects of ammonia have not often been tested in the past. Based on experiments in Scotland, long-term critical levels of 3 µg m-3 were suggested to protect N-sensitive higher plant species and of 1 µg m-3 for lichens and mosses (Cape et al., 2009). In the past ten years only few studies have dealt with ammonia and communities other than bog ecosystems have not often been addressed.