Soil food web structure during ecosystem development after land abandonment
Soil food web structure during ecosystem development after land abandonment
复制标题
DOI：
10.1016/j.apsoil.2007.11.002
复制
发表时间：
2008-05-01
影响因子：
4.8
通讯作者：
de Ruiter, Peter C.
中科院分区：
文献类型：
--
作者：
Holtkamp, Remko;Kardol, Paul;de Ruiter, Peter C.
在废弃的农业用地上重建自然物种丰富的石南荒原是西北欧常见的土地利用变化。然而，它可能需要几十年才能重新建立自然物种丰富的石南植被。研究表明，土壤食物网的发育速率与土壤过程和土壤食物网的组成有关，本文测定了3块弃耕2年、9年和22年的荒地和一片石楠地的土壤食物网组成。为了表征食物结构，我们定义了四个营养级和一个根，真菌和细菌的能量通道。我们假设，随着废弃时间的增加，即田间年龄，（1）基本资源水平生物量，即土壤有机质（SOM）和根系，将增加，从而也增加了更高营养水平的生物量，（2a）根能量通道生物量将减少，（2b）真菌能量通道生物量将增加，结果表明，随着林龄的增加，基本资源水平和第一营养级的生物量确实增加，但较高营养级的生物量不增加。目前尚不清楚是什么原因导致了高营养水平的增加，可能是自上而下或自下而上的力量发挥了作用，根能量通道生物量减少，真菌通道生物量增加，但细菌通道生物量也随着田间年龄的增加。细菌通道生物量的增加与这一假设相矛盾，但与所观察到的SOM数量的增加和SOM质量的下降相一致。总体而言，结果表明，地下食物网的变化滞后于地上植被的变化。这种时间滞后可能会妨碍次生植被的演替。因此，了解这些时间滞后可能有助于制定管理计划，改善土地转换进程。(C)2007 Elsevier B.V.保留所有权利。
The re-establishment of natural species rich heathlands on abandoned agricultural land is a common land use change in North-West Europe. However, it can take several decades to re-establish natural species rich heathland vegetation. The development rate has found to depend both on soil food web composition and on soil processes.We measured the soil food web composition in three ex-arable fields abandoned 2,9 and 22 years ago and in a heathland. To characterize food structure, we defined four trophic levels and a root, fungal and bacterial energy channel. We hypothesized that with increasing time since abandonment, i.e. field age, (1) the basic resource level biomass, i.e. soil organic matter (SOM) and roots, will increase and thereby also that of biomasses at higher trophic levels, (2a) the root energy channel biomass will decrease, (2b) the fungal energy channel biomass will increase, and (2c) the bacterial energy channel biomass will not change.The results showed that biomasses at the basic resource level and at the first trophic level indeed increased with field age, but not the biomasses at higher trophic levels. It is not clear what the cause of the lack of increase in higher trophic levels was, possibly top-down or bottom-up forces played a role.The root energy channel biomass decreased and the fungal channel increased as hypothesized, but the bacterial channel biomass also increased with field age. The increase of the bacterial channel biomass contradicted the hypothesis, but agreed with the observed increase in SOM quantity and lack of decrease in SOM quality.On overall, results show that changes in belowground food webs lag behind changes of the aboveground vegetation. Such time lags may hamper secondary vegetation succession. Understanding those time lags may therefore help to develop management schemes improving land conversion processes. (C) 2007 Elsevier B.V. All rights reserved.