
TY  - JOUR
A1  - Van, Der Valk AG 
A1  - Attiwill, PM 
T1  - Acetylene Reduction in an <I>Avicennia marina</I> Community in Southern Australia
JF  - Australian Journal of Botany
JO  - Aust. J. Bot.
Y1  - 1984
VL  - 32
IS  - 2
SP  - 157
EP  - 164
KW  - 
UR  - https://doi.org/10.1071/BT9840157 
N2  - Rates of C2H2 reduction associated with decomposing leaf litter of Avicennia marina (white mangrove) reached 469 nmol C2H4 g-1 h-1 in air after 21 days of decomposition. Maximum rates of C2H2 reduction measured in sea water were 328 nmol C2H4 g-1 h-1 for leaf litter confined in mesh bags and 352 nmol C2H4 g-1 h-1 for unconfined leaf litter; the rates in sea water were always, and often substantially, lower than rates in air. Rates of decomposition and C2H2 reduction were less in leaf litter confined in mesh bags than in unconfined litter. Decomposing dead fibrous roots and live roots showed average rates of C2H2 reduction in interstitial water of only 9.3 and 3.5 nmol C2H4 g-1 h-1, respectively. During decomposition of leaf litter, the concentration of nitrogen increased; 41-64% of this increase was estimated to be the direct result of N2 fixation. No change in nitrogen concentrations occurred in decomposing dead roots or in live roots. N2 fixation associated with decomposing leaf litter and dead roots, and with live roots and surficial sediments, is thought to supply about 40% of the nitrogen required annually by the Avicennia marina trees. This estimate is relatively low in comparison with data for other marine wetlands, and it follows from the low rates of C2H2 reduction associated with the root system and the sediments. 
ER  -

