Quantifying ecosystem rejuvenation: foliar nutrient concentrations and vegetation communities across a dust gradient and a chronosequence
Quantifying ecosystem rejuvenation: foliar nutrient concentrations and vegetation communities across a dust gradient and a chronosequence
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DOI：
10.1007/s11104-013-1685-1
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发表时间：
2013-06-01
期刊：
影响因子：
4.9
通讯作者：
Condron, Leo M.
中科院分区：
文献类型：
--
作者：
Eger, Andre;Almond, Peter C.;Condron, Leo M.
由于陆地表面的长期风化，风成养分的贡献对于维持生态系统肥力和避免退化至关重要。然而，研究认为，定性和定量的影响，粉尘沉积对生态系统的发展是罕见的。我们通过研究新西兰南岛西海岸一个6,500年的沙丘脊和一个在超湿、高沥滤环境中不受灰尘沉积影响的时间序列，沿着一个活跃的全新世灰尘通量梯度，来解决这一知识空白。我们测量了两个主要树种的叶片营养成分，沿着两个序列（Dacrydium cupressinum，Prumpitys ferruggelium），并对调查样地的植被群落进行了分析。沿着沙尘梯度，叶片磷（P）浓度随沙尘通量的增加而增加，最高可达50%。在附近的年代序列中，在最初的2,000年内，叶[P]迅速下降了50%，之后达到平稳状态。在最高的尘埃通量率，最接近尘埃源，叶[P]匹配的表面是5,702至6,098年比6,500岁的沙丘年轻。植被群落沿着灰尘梯度表现出典型的演替群落上未成熟的土壤（红壤，Inceptisol）的物种的相对丰度增加，而冠层覆盖和断面积（总，被子植物，针叶树）没有响应增加灰尘沉积。树蕨断面积，然而，积极响应的灰尘flux.We的结论是，自然发生的灰尘沉积可以施肥生态系统显着，创造一个叶面营养状态通常发现在陆地表面，高达94%的年轻和植被群落是典型的演替阶段的年轻土壤（红壤，Inceptisols）。我们怀疑，这些观察结果主要反映了更多的植物有效磷在生态系统中的灰尘施肥的结果。因此，灰尘沉积可以是避免或延缓生态系统向自然退化发展的重要机制。这是第一个研究直接量化的施肥能力的自然灰尘沉积校准其复壮效果对一个良好的过时的演替植被序列。
Due to long-term weathering of land surfaces, aeolian nutrient contributions can become essential to maintain ecosystem fertility and avoid retrogression. However, studies that consider the qualitative and quantitative effects of dust deposition on ecosystem development are rare. We addressed this knowledge gap by studying an active Holocene dust flux gradient along a 6,500 year old dune ridge and a nearby chronosequence outside the influence of dust deposition in a super-humid, high leaching environment, on the west coast of the South Island in New Zealand.Along both sequences we measured foliar nutrients of two main tree species (Dacrydium cupressinum, Prumnopitys ferruginea) and analysed vegetation communities in survey plots.Along the dust gradient, foliar phosphorus (P) concentrations increased up to 50 % with increasing dust flux. Across the nearby chronosequence a rapid decline of up to 50 % in foliar [P] occurred within the first 2,000 years after which it plateaued. At the highest dust flux rate, closest to the dust source, foliar [P] matched those of surfaces that are 5,702 to 6,098 years younger than the 6,500 year old dune. Vegetation communities along the dust gradient showed increasing relative abundance of species typical for successional communities on immature soils (Entisols, Inceptisols), while canopy cover and basal area (total, angiosperms, conifers) did not respond to increasing dust deposition. Tree fern basal area, however, positively responded to the dust flux.We conclude that naturally occurring dust deposition can fertilise ecosystems significantly, creating a foliar nutrient status normally found on land surfaces that are up to 94 % younger and vegetation communities that are typical for successional stages on young soils (Entisols, Inceptisols). We suspect that these observations mainly reflect more plant-available P in the ecosystem as a result of dust fertilisation. Thus, dust deposition can be an important mechanism to avoid or retard the development of an ecosystem toward natural retrogression. This is the first study to directly quantify the fertilising capacity of natural dust deposition by calibrating its rejuvenating effect against a well-dated successional vegetation sequence.