Detailed studies on the sediment budget may reveal valuable insights into the successive build-up of the Canterbury Plains and their modification by Holocene fluvialaction connected to major braided rivers. Additionally, they bear implications beyond these fluvial aspects. Palaeoseismological studies claim to have detected signals of major Alpine Fault earthquakes in coastal environments along the eastern seaboard of the South Island (McFadgen and Goff, 2005). This requires high connectivity between the lower reaches of major braided rivers and their mountain catchments to generate immediate significant sediment pulses. It would be contradictory to the above mentioned hypothesis though. Obtaining better control on sediment budgets of braided rivers like the Waimakariri River will finally add significant value to multiple scientific and applied topics like regional resource management. An essential first step of sediment budget studies Is to systematically map the geomorphology, conventionally in the field and/or using remote-sensing applications, to localise, genetically identify, and classify landforms or entire toposequences of the area being investigated. In formerly glaciated mountain environments it is also indispensable to obtain all available chronological information supporting subsequent investigations.
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".
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".
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".
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".
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.
