Tenterden wetlands in the dry

Well they were dry really, but they would be wet in winter after some rains.

This biological survey weekend was organised by Greenskills in Denmark. It was part of the Gondwana Link Program. As part of this process we surveyed Melaleuca species growing on the range of wetland types found on the property. There was an interesting succession of wetland types ranging from those in pretty much original condition to ecosystems that were in a state of collapse to one that had adapted and recovered into a new ecosystem type. The changes in the wetland systems are due mainly to the large scale farmland clearing surrounding this property. The collapse of the Melaleuca species was accompanied by rising pH (alkalinity) and increasing salinity, a complexity I was unaware of having always thought it was just the salt.

Edge of healthy wetland system

This first image shows the outer edge of a healthy wetland. It is situated within a sandy bowl, with steep sides. Healthy banksia and jarrah woodlands surround it and even a healthy stand of Nuytsia floribunda. Mel. cuticularis (salt tolerant) and Mel. lateritia were the dominant species with a couple of  very large Mel. rhaphiophylla (likes fresh water) on the edges. In summer the Mel. lateritia is covered with bright orange-red flowers and is a haven for birds.

Healthy paperbarks in the middle of the wetland

The next two images show the difference between a healthy stand Mel. lateritia and a collapsed stand. Apparently the wetlands began to show first signs of change thirty years ago. The wetland on the left started to show signs of change in the last few years. Now it is all dead.  The character of the soil changes too with the loss of organic matter. It must be difficult to watch this happening knowing that this property has been largely uncleared and yet these changes are still occurring.

Collapsed stand - note the bare soil

Healthy stand of Melaleuca lateritia 

This image of a samphire covered depression was a Mel. Lateritia wetland that collapsed some years ago. It has now been colonised by the samphires which can handle the changed salinity and soil pH. It just goes to show the resilience of nature.

Samphire covered depression

The final images are from some paperbark swamps (dry) that are in the process of collapsing. In the first image we are testing the pH of the soil which was slightly alkaline. This swamp was once covered in tall sedges which have now all but disappeared. The paperbark trees Mel. cuticularis are still surviving. The image of another swamp shows the paperbark trees all dead. Around the edges the trees are still surviving. The current owners told us of playing in these swamps as children amongst the sedges and the bird life.

Testing pH in the middle of the dry swamp

Dead paperbark trees in the middle of another dry swamp

It is not all doom and gloom. The timber plantations should help to arrest the decline in the ecosystems. Some areas have been set aside for sandalwood plantations which will add another dimension to the enterprise. Over the weekend we saw and heard a large number of birds including the southern yellow robin, scarlet robin, wrens, a number of parrot species and lots of tiny birds. I saw most of the birds in the interface between the plantations and the wandoo woodlands. The fact that the plantation eucalypts were flowering probably helped. One evening  I heard  flapping in my camper, expecting it was a big moth I was so surprised when I found it was a microbat. It's tiny body, maybe 3cm long was covered in soft and silky grey fur with delicate membranes stretched on its wings. On letting it go it swooped up and away into the night air. 

Campsite with Eucalyptus plantation in the background

Big Ben mused about his time spent on the property ‘I always felt at home here and love the peace from being in the bush. ... I think many people today may be suffering from nature deficit disorder … not enough contact with the natural world … too stressed. We all need a place where we can feel at home. ” I’d never heard of nature deficit disorder before but discovered it was first used by Richard Louv in his book Last Child in the Woods written in 2005. Briefly Louv believes that people’s relationship to nature has changed particularly over the last few decades from an interactive, playful, get your hands dirty relationship to one of knowledge about but little hands on experience of the natural world. In Louv’s words

'This book explores the increasing divide between the young and the natural world, and the environmental, social, psychological, and spiritual implications of that change. It also describes the accumulating research that reveals the necessity of contact with nature for healthy child - and adult- development.'

It is an interesting concept. I haven’t read the book so I can’t pass judgement on his proposition except to say that intuitively it feels right. As children, my siblings and I ran wild in the bush, something which doesn't often happen for young children these days. Kids play these days tends to be more supervised, less risky and a lot of their play interfaces with electronic media not wild or even tame bits of nature. Certainly in the cities there is a lot less bush left, having been bulldozed and reshaped for housing estates.   The rivers and swamps (that remain) have been beautified, grassed and mowed and ‘civilised’ in other ways. I know that young city kids are extraordinarily excited to be able to wander on paths in the bush and clamber over fallen logs and stumps around here. In the words of two young brothers “this is the best park ever”.