Impact of infection on canopy and forest floor plant nutrient concentrations and fluxes in a kauri-dominated forest.

Kauri dieback, caused by , is a biotic disturbance that poses a recent threat to the survival of kauri () forests in New Zealand. Previous studies have shown that throughfall and stemflow play an important role in the kauri forests' internal nutrient cycle. However, the effects of infection on canopy and forest floor nutrient fluxes in kauri forests remain unknown.

The evolution of hummock-depression micro-topography in an alpine marshy wetland in Sanjiangyuan as inferred from vegetation and soil characteristics.

The hummock-depression micro-topography characteristics of the alpine marshy wetland in Sanjiangyuan are indicative of wetland degradation and the process by which healthy wetlands are transformed into flat grasslands. The aim of the present study was to examine changes in plant community structure and soil characteristics in a hummock-depression micro-topography along a degradation gradient. We observed that: (a) the height and cover of dominant hydrophytes decreased gradually with an increase in degradation severity, leading to replacement by xerophytes; (b) with the transition from healthy to degraded wetlands, hummocks became sparser, shorter, and broader and became merged with nearby depressions; water reserves in the depressions shifted from perennial to seasonal, until they dried out completely; and (c) soil moisture content, porosity, hardness, and organic matter gradually decreased by 30.