11 December 2014

Let's stick together


It's been just over four years since the Greendale 7.1 earthquake that shook us up here in Lincoln and almost four years since the major aftershock that destroyed a good chunk of Christchurch. Time flies and time heals. There are few signs around Lincoln of the quakes (although the local Catholic church was only demolished this week after being empty and forlorn for all of this time). Around the university we still have several large buildings that have been closed since the quakes and are yet to be demolished. Overall, though, Lincoln and its surrounds are going well. It's a different story in Christchurch. While much of the demolition around the city centre has finished and there is a forest of cranes and building sites, as we move out further east towards the seaside we come to major areas of damage that are little changed since the fateful day in February 2011. I travelled through these suburbs on the weekend and it is genuinely distressing to do this. The people living in these areas with wrecked roads, poor infrastructure, no real drainage and so on must be truly resilient (or numb). Probably one of the most affecting sights are the large tracks of suburbs where scores of houses have now been removed and the land is becoming unkempt wilderness. Whole streets of houses are gone. Dotted in amongst these wild areas are houses and families who, through the oddities of these kinds of events, were fortunate to be living on a slightly rocky substrate, or a fractionally higher rise. As I drove around, feeling slightly seasick on the undulating roads, I wondered how these isolated homes could keep a sense of connection in these areas that once had tightknit communities.
High Street, Christchurch

A lot of the people from these areas have moved to various outlying towns like Rangiora or Rolleston. So are there now little bits of New Brighton in Amberley? Or pieces of Parkland in Halswell? That's unlikely as people from this diaspora have gone in all directions. They will have to adapt and change to the communities that they move to. There seems to be a number of links between what has happened in Christchurch and issues that we have in conservation.

As populations decline you have a few options. You could halt the decline and then grow the population again (in New Zealand this often means controlling introduced predators). You could move the local population to another safer or more productive site (in New Zealand such translocations have often been to offshore islands). In the near future you will be able to clone and artificially generate genetic variation in individuals. However, much of this work involves single species translocations. This is like moving one family out of their suburb. Will they like and flourish in the new site? Time will tell. Will they retain the attributes of their original community? Unlikely. What if we could relocate whole streets of families to new streets elsewhere? Will they like and flourish in the new site? Again, time will tell. Will they retain the attributes of their original community? The chances are much higher.

Stephane Boyer from Lincoln University has suggested that conservation translocations would be much more successful if they are community translocations. He has published in Science on this topic. Stephane has worked in mitigating the effects of open mines. One of the techniques that they have shown to work is in taking soil, plants, and the invertebrates and microbes that come along with them, and placing the whole lot in a different site. This is remarkably successful in allowing these communities to survive and to remain functioning much as they have always done. He argues that in conservation translocations, we should also be more focussed on moving multiple species from an area and not just an endangered birds or plant. As we move into a period of climate change, where whole local habitats are threatened, we may need to increasingly think about using these techniques. There might also be some ideas that we could take from this to help with preserving human communities.

Postscript: Less than a day after writing this piece we were woken in the wee hours by a magnitude 4.5 aftershock centred more or less under Lincoln. That was the 542nd aftershock quake since September 10 2010 to register over 4. As I lay in my bed wondering whether this was going to escalate in something nastier I did think back to this article and thought that one doesn't have to go over to the centre or eastside of Christchurch to be reminded of the legacy of the quake.

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