Successional patterns along soil development gradients formed by glacier retreat in the Maritime Antarctic, King George Island
Successional patterns along soil development gradients formed by glacier retreat in the Maritime Antarctic, King George Island
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DOI：
10.1186/s40693-016-0056-8
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发表时间：
2016-01-01
影响因子：
2.2
通讯作者：
Guggenberger, Georg
中科院分区：
文献类型：
--
作者：
Boy, Jens;Godoy, Roberto;Guggenberger, Georg
背景资料：海洋南极洲受到气候变化和冰川加速退缩的严重影响，形成土壤发育的时间梯度。该地区土壤发育和植物演替的演替模式在很大程度上是未知的，因为这两个过程之间的反馈机制。在这里，我们确定了三个时间梯度，代表水平和垂直冰川退缩，以及形成凸起的海滩，由于均衡隆起，并描述土壤形成和植物演替沿着他们。我们的假设是：（i）南极洲的植物能够调节土壤发育中的两个基本参数，有机C含量和pH值，沿着时间梯度，导致有机碳和土壤酸度在相对较短的时间尺度上增加，（ii）土壤发育诱导沿着这些梯度的演替，（iii）随着土壤发育的增加，结果：在所有时间梯度上，随着年龄的增长，土壤发育导致土层分化、碳积累和pH值升高。冰川退缩后，光合自养演替迅速发生，但苔藓和地衣通过假根或根茎与土壤相互作用的发生仅在后期观察到。地栖苔藓和地衣群落是土壤演替的顶极群落，南极发草D. anastritica仅限于鸟类土壤。D也不是。结论：在南极海洋环境中，冰川退缩形成的时间梯度是可以确定的，在那里可以观察到土壤发育和植物演替的显著速度，尽管鸟类粪便引起的施肥梯度会导致伪演替。因此，在南极洲的无冰表面的大部分是殖民地的植物群落与土壤的凋落物输入，而不是通过直接转移到土壤的光合作用相互作用。
Background: Maritime Antarctica is severely affected by climate change and accelerating glacier retreat forming temporal gradients of soil development. Successional patterns of soil development and plant succession in the region are largely unknown, as are the feedback mechanisms between both processes. Here we identify three temporal gradients representing horizontal and vertical glacier retreat, as well as formation of raised beaches due to isostatic uplift, and describe soil formation and plant succession along them. Our hypotheses are (i) plants in Antarctica are able to modulate the two base parameters in soil development, organic C content and pH, along the temporal gradients, leading to an increase in organic carbon and soil acidity at relatively short time scales, (ii) the soil development induces succession along these gradients, and (iii) with increasing soil development, bryophytes and Deschampsia antarctica develop mycorrhiza in maritime Antarctica in order to foster interaction with soil.Results: All temporal gradients showed soil development leading to differentiation of soil horizons, carbon accumulation and increasing pH with age. Photoautptroph succession occurred rapidly after glacier retreat, but occurrences of mosses and lichens interacting with soils by rhizoids or rhizines were only observed in the later stages. The community of ground dwelling mosses and lichens is the climax community of soil succession, as the Antarctic hairgrass D. antarctica was restricted to ornithic soils. Neither D. antarctica nor mosses at the best developed soils showed any sign of mycorrhization.Conclusion: Temporal gradients formed by glacier retreat can be identified in maritime Antarctic, where soil development and plant succession of a remarkable pace can be observed, although pseudo-succession occurs by fertilization gradients caused by bird feces. Thus, the majority of ice-free surface in Antarctica is colonized by plant communities which interact with soil by litter input rather than by direct transfer of photoassimilates to soil.