Monday, 9 November 2015

When is pond not a pond? An existential crisis and the probolem of choosing the best

Here is an example of how the Druridge Bay field ponds fluctuate in area depending on the rainfall. This might be an even more existential questions: can you have a pond that has no water in it, is it still a pond? Yes it is, although I am not sure how long you can go before saying it is no longer a pond. My personal preference would be years. I am sure there will be ponds in some desert habitat that only fill very rarely with long hard dry years in between. The pond in the photos above is just in the field to the right hand side of the entrance to Ellington Caravan Park. It is wet most years and well established. On the left is the pond in mid July 2012. Yes, those are rain drops smudging the lens. Still, it is not lashing rain so this must have been a particularly dry day given the deluge of 2012. On the left July 2014. No water an there had not been for a while, instead carpet of weeds that weave a distinct carpet over the exposed earth. Mayweeds and annual meadow grass, bistorts and cudweed. In 2012 the plant life was dominated by other species growing luxuriantly in the damp summer, although the overall tick list was much the same.

Which is the better pond? That could be a classic question asked of conservationists. Is it the overflowing quagmire of 2012 with thick tufts of toad rush and even underwater starworts? Or maybe the dried out mayweed and cudweed carpet of 2014. Both are good, both are typical of the Druridge fields. The differences between years do not matter, they are part of the natural disturbance and change. The real challenge will be if the local wildlife is exposed to weather conditions so different to anything they are used to that they cannot cope. The plants seemed to cope with 2012 but I do not know about the invertebrates because I was not monitoring them Butterflies took a massive hit, but butterflies like it sunny and dry. I am worried that the invertebrates may have been hit harder than we know, especially those with flying adult stages to their life history

No comments:

Post a Comment