Bringing back the dead with old ecology photos

Mallee Swale Eucalypts Wyperfeld 1982 Cheal

Take a close look at the coppicing trees in the old photo above. Notice anything unusual?

Perhaps it looks like any other stand of burnt mallee? Perhaps it does. But most of the trees aren’t resprouting after a fire. They aren’t recovering from drought, insect attack or damage by humans either. What could have caused the damage? Continue reading

Ageing the mallee: a history in burnt trees

mallee-spinifex 3

Coppicing Mallee trees and Spinifex grass in Mungo National Park. Original photo: Visit Mungo.

Trees grow short in the mallee. Little rain and poor soils stunt their growth. Over thousands of square kilometers, in semi-arid Victoria, South Australia and New South Wales, many mallee eucalypts reach just 6 to 7 meters high. The short trees burn well, especially when growing above Spinifex Continue reading

Natural regeneration: connecting regional Australia

planting1

Want to re-connect fragmented landscapes? Where would you start? With natural regeneration of course.

Natural regeneration of native trees and shrubs is abundant in many regions, where it provides valuable habitat and linkages between patches of native vegetation. Last week I gave a talk at the Biodiversity Across The Borders conference in Ballarat in a session on landscape connectivity, on behalf of my co-authors Lisa Smallbone and Alison Matthews. Our talk covered four topics.

  1. Why do we get extensive natural regeneration in some regions?
  2. Where do we find lots of natural regeneration in Victoria?
  3. How valuable is natural regeneration for birds?
  4. How can we incorporate natural regeneration in connectivity planning?

If  you didn’t get to last week’s conference, you can now watch the video of the talk, courtesy of YouTube.

Continue reading

Dense old trees: bitter and twisted ‘charismatic megaflora’

Suppressed trunk inverseWe all know an old paddock tree when we see one: broad, deep, canopy; sagging, tangled branches; broken boughs full of hollows. The classic woodland tree. But how do you recognize an old tree that grew – not in the open – but in a closed, dense stand? It won’t have a big, wide canopy nor a thick, wide trunk if its growth was suppressed by neighbors. Continue reading

Reading the bush: juxtapositions in history

old-callitris 2013cAn old post about an old post…

Everyone sees something different in a patch of bush. I usually wonder: were these patterns that we see created by natural forces (such as soils and geology) or by a hidden mosaic of past disturbances?

Most times, I work in ecosystems with a long history of human disturbances, such as clearing and felling, grazing and burning. Their imprints can be both indelible and invisible, but more often, just plain forgotten. Yet we need to know how disturbances have altered natural ecosystems, so we can predict how our activities will alter ecosystems in the future.

The best way to see the imprint of past disturbances is by combining field evidence and archival documents, like old reports and maps. But we often have to rely solely on field skills. Just as the science of geology required the law of superposition – which simply states that sediments were laid down sequentially, so lower strata are older than upper strata – so historical ecology requires the ability to see key juxtapositions. By observing how things are arranged in space, we can develop a chronology of past events and an informed narrative of ecological change. Continue reading