Fenner School of Environment and Society, ARC Centre of Excellence for Environmental Decisions, and National Environment Research Program, The Australian National University, Canberra, Australia.
PLoS One. 2012;7(4):e34527. doi: 10.1371/journal.pone.0034527. Epub 2012 Apr 6.
The value for biodiversity of large intact areas of native vegetation is well established. The biodiversity value of regrowth vegetation is also increasingly recognised worldwide. However, there can be different kinds of revegetation that have different origins. Are there differences in the richness and composition of biotic communities in different kinds of revegetation? The answer remains unknown or poorly known in many ecosystems. We examined the conservation value of different kinds of revegetation through a comparative study of birds in 193 sites surveyed over ten years in four growth types located in semi-cleared agricultural areas of south-eastern Australia. These growth types were resprout regrowth, seedling regrowth, plantings, and old growth. Our investigation produced several key findings: (1) Marked differences in the bird assemblages of plantings, resprout regrowth, seedling regrowth, and old growth. (2) Differences in the number of species detected significantly more often in the different growth types; 29 species for plantings, 25 for seedling regrowth, 20 for resprout regrowth, and 15 for old growth. (3) Many bird species of conservation concern were significantly more often recorded in resprout regrowth, seedling regrowth or plantings but no species of conservation concern were recorded most often in old growth. We suggest that differences in bird occurrence among different growth types are likely to be strongly associated with growth-type differences in stand structural complexity.Our findings suggest a range of vegetation growth types are likely to be required in a given farmland area to support the diverse array of bird species that have the potential to occur in Australian temperate woodland ecosystems. Our results also highlight the inherent conservation value of regrowth woodland and suggest that current policies which allow it to be cleared or thinned need to be carefully re-examined.
大面积原生植被的生物多样性价值已得到充分证实。再生植被的生物多样性价值在全球范围内也越来越受到认可。然而，再植被可能有不同的起源，不同类型的再植被的生物群落丰富度和组成可能存在差异。在许多生态系统中，不同类型的再植被的保护价值仍不清楚或知之甚少。我们通过对澳大利亚东南部半开垦农业区四个生长类型的 193 个地点进行了十年的鸟类调查，比较研究了不同类型的再植被的保护价值。这些生长类型是萌蘖再生、幼苗再生、种植和原生林。我们的调查结果有几个关键发现：（1）种植、萌蘖再生、幼苗再生和原生林的鸟类群落存在显著差异。（2）不同生长类型中检测到的物种数量存在显著差异；种植区有 29 种，幼苗再生区有 25 种，萌蘖再生区有 20 种，原生林区有 15 种。（3）许多受保护关注的鸟类物种在萌蘖再生、幼苗再生或种植区中更为常见，但在原生林中没有记录到受保护关注的物种。我们认为，不同生长类型之间鸟类出现的差异很可能与林分结构复杂性的生长类型差异密切相关。我们的研究结果表明，在给定的农田面积内，可能需要多种植被生长类型来支持澳大利亚温带林地生态系统中可能存在的各种鸟类物种。我们的研究结果还强调了再生林地的固有保护价值，并表明当前允许其被清除或变薄的政策需要重新仔细审查。
