BeckerFraserPhotos September 2011 photograph 242

Images, UC QuakeStudies

Photograph captioned by BeckerFraserPhotos, "This is a pile of munched concrete rubble".

Bike Ride in the East Side - Photograph 02

Images, UC QuakeStudies

The sewage treatment ponds in Bromley. In the distance trucks and diggers can be seen piling up liquefaction silt. The photographer comments, "Looking NW from the causeway through the sewage wetlands. Mountains of liquefaction silt are being piled up near the corner of Breezes Rd and SH74-Anzac Drive".

Bike Ride in the East Side - Photograph 04

Images, UC QuakeStudies

Trucks and diggers build large piles of liquefaction silt. In the foreground can be seen the Bromley sewage treatment ponds. The photographer comments, "Looking NW from the causeway through the sewage wetlands. Mountains of liquefaction silt are being piled up near the corner of Breezes Rd and SH74-Anzac Drive".

Bike Ride in the East Side - Photograph 03

Images, UC QuakeStudies

Trucks and diggers build large piles of liquefaction silt. One pile has been covered with plastic sheeting, weighted down with tyres. In the foreground can be seen the Bromley sewage treatment ponds. The photographer comments, "Looking NW from the causeway through the sewage wetlands. Mountains of liquefaction silt are being piled up near the corner of Breezes Rd and SH74-Anzac Drive".

Bike Ride in the East Side - Photograph 05

Images, UC QuakeStudies

Trucks and diggers build large piles of liquefaction silt. One pile has been covered with plastic sheeting, weighted down with tyres. In the foreground can be seen the Bromley sewage treatment ponds. The photographer comments, "Looking NW from the causeway through the sewage wetlands. Mountains of liquefaction silt are being piled up near the corner of Breezes Rd and SH74-Anzac Drive".

Size-specific tree mortality varies with neighbourhood crowding and distur…

Research Papers, Lincoln University

Tree mortality is a fundamental process governing forest dynamics, but understanding tree mortality patterns is challenging because large, long-term datasets are required. Describing size-specific mortality patterns can be especially difficult, due to few trees in larger size classes. We used permanent plot data from Nothofagus solandri var. cliffortioides (mountain beech) forest on the eastern slopes of the Southern Alps, New Zealand, where the fates of trees on 250 plots of 0.04 ha were followed, to examine: (1) patterns of size-specific mortality over three consecutive periods spanning 30 years, each characterised by different disturbance, and (2) the strength and direction of neighbourhood crowding effects on sizespecific mortality rates. We found that the size-specific mortality function was U-shaped over the 30-year period as well as within two shorter periods characterised by small-scale pinhole beetle and windthrow disturbance. During a third period, characterised by earthquake disturbance, tree mortality was less size dependent. Small trees (,20 cm in diameter) were more likely to die, in all three periods, if surrounded by a high basal area of larger neighbours, suggesting that sizeasymmetric competition for light was a major cause of mortality. In contrast, large trees ($20 cm in diameter) were more likely to die in the first period if they had few neighbours, indicating that positive crowding effects were sometimes important for survival of large trees. Overall our results suggest that temporal variability in size-specific mortality patterns, and positive interactions between large trees, may sometimes need to be incorporated into models of forest dynamics.