Photos taken in Lyttelton showing the demolition of various buildings following the February 22 earthquake. File reference: CCL-2011-04-29-Lyttelton-Demolition-P1120223 From the collection of Christchurch City Libraries.
Photos taken in Lyttelton showing the demolition at various locations following the February 22 earthquake. File reference: CCL-2011-05-20-Lyttelton-Demolition-P1120445 From the collection of Christchurch City Libraries.
The TimeBank book swap in front of the library. As the library has been closed since the earthquake, members of the community put together a book swap service which was later continued in the information centre.
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.
A photograph captioned by BeckerFraserPhotos, "A sign in the front doors of the Lyttelton Library on London Street, reading 'Lyttelton Service Centre now open'".