Current loads of coarse woody debris on southeastern Australian floodplains: Evaluation of change and implications for restoration

摘要: We evaluated the status of coarse woody debris (CWD, fallen wood) on floodplains southern Murray-Darling basin southeastern Australia. The are dominated floristically by river red gum Eucalyptus camaldulensis. Aerial survey techniques were used to estimate amounts within 200 m channels along 2,442 km 11 rivers system, including Murray and Darling Rivers Anabranch. Aerially based indices converted into wood volumes using ground-truthing at a selection sites; there was strong correlation between index values measured volume densities. For thickly forested sites such as Barmah, Gunbower Island, Ovens floodplains, aerial method not useful, so ground measurements randomly positioned forests used. Volumes translated mass conversion factors drawn from literature. estimated that total tonnage approximately 221,000 ha floodplain 4.175 ± 0.579 X 10 6 tonne. In larger blocks (>7,000 ha), mean densities ranged 12 tonne/ha lower Goulburn up 24 Barmah State Forest. area-weighted for entire area 19 tonne/ha. A main purpose research place these figures an historical perspective evaluate implications restoration. thorough search documentation revealed no extant data upon which pre-European settlement levels. information apparently undisturbed unmanaged site in Millewa New South Wales basis. Wood density corresponded figure 125 wood-mass density. By this we CWD levels may be order 15% Full restoration surveyed would require 23.5 tonne, is equivalent about 600,000 mature (1 diameter breast height) trees or amount timber derived clear felling 115,000 forest current stocking discuss massive deficit possible short- long-term solutions.