 |
| Titel |
Response of respiration and nutrient availability to drying and rewetting in soil from a semi-arid woodland depends on vegetation patch and a recent wildfire |
| VerfasserIn |
Q. Sun, W. S. Meyer, G. R. Koerber, P. Marschner |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1726-4170
|
| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 12, no. 16 ; Nr. 12, no. 16 (2015-08-27), S.5093-5101 |
| Datensatznummer |
250118077
|
| Publikation (Nr.) |
 copernicus.org/bg-12-5093-2015.pdf |
|
|
|
|
|
| Zusammenfassung |
| Semi-arid woodlands, which are characterised by patchy vegetation
interspersed with bare, open areas, are frequently exposed to wildfire.
During summer, long dry periods are occasionally interrupted by rainfall
events. It is well known that rewetting of dry soil induces a flush of
respiration. However, the magnitude of the flush may differ between
vegetation patches and open areas because of different organic matter
content, which could be further modulated by wildfire. Soils were collected
from under trees, under shrubs or in open areas in unburnt and burnt sandy
mallee woodland, where part of the woodland experienced a wildfire which
destroyed or damaged most of the aboveground plant parts 4 months before
sampling. In an incubation experiment, the soils were exposed to two
moisture treatments: constantly moist (CM) and drying and rewetting (DRW).
In CM, soils were incubated at 80 % of maximum water holding capacity (WHC) for
19 days; in DRW, soils were dried for 4 days, kept dry for another 5
days, then rewetted to 80 % WHC and maintained at this water content until
day 19. Soil respiration decreased during drying and was very low in the dry
period; rewetting induced a respiration flush. Compared to soil under shrubs
and in open areas, cumulative respiration per gram of soil in CM and DRW was
greater under trees, but lower when expressed per gram of total organic carbon (TOC). Organic matter
content, available P, and microbial biomass C, but not available N, were
greater under trees than in open areas. Wild fire decreased the flush of
respiration per gram of TOC in the open areas and under shrubs, and reduced TOC
and microbial biomass C (MBC) concentrations only under trees, but had little effect on available
N and P concentrations. We conclude that the impact of wildfire and DRW
events on nutrient cycling differs among vegetation patches of a native
semi-arid woodland which is related to organic matter amount and
availability. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|