40
Joan Josep Ibanez, Marfa Jose Lled6, Juan Rafael Sanchez and Ferran Roda
closed-canopy plots averaged 3.9 Mg ha- 1 year- 1 for a 2-year period (Mayor
1990; F. Roda, unpublished data). In the permanent plot, litterfall during
3 years averaged 4.8 Mg ha- 1 year- 1 (Verdu 1984). In the different study sites
and periods, leaves contributed 57-66% to total fine litterfall, as multi-year
averages.
Mayor (1990) analyzed the contributions of litterfall and current woody
biomass increment to primary production in closed-canopy plots at Montseny. Litterfall was the major component, accounting on average for 57% of
the aboveground production, with woody biomass increment accounting for
the remaining 43%. Despite such distribution, aboveground primary production was more strongly correlated across plots with biomass increment
than with litterfall (r = 0.91 and r = 0.76, respectively; P < 0.001 in both cases;
Fig. 3.3). There was no significant correlation between litter fall and biomass
increment. These patterns can be interpreted assuming that production of
fast-turnover canopy components (leaves, twigs, and fruits) has higher priority than secondary. growth of woody tissues. As a consequence, spatial
a
~ ~ ~10 r--------------------------'
ro ro 9
E Q)
·c >.
0. ~
8
-g ~ 7
:J
en
e ~ 6
0 ) -
~ c 5
o ,g 4
~ u
•
•
• :
•
•
•
•
• •
• •
• •
•
r= 0.76
P=O.OOO3
a; -5 3
Z
e 2 L-____ -'--____ --..JI...-____ -L... ____ ----:
0.
1
2
3
4
5
Litte rfa II (Mg ha- 1 yea(1)
b
~~10 r--------------------------.
ro ro 9
E Q)
"L:
>.
0. ~
8
"0
ro
c .c 7
:J
0)
e 6 6
0)
Q)
c 5
~ 0
.D U 4
ro :J
• •
.'
• •
• •
•
•
•
•
•
•••
r= 0.91
P a; "0 3
Z e 2 L-__ ---l ____ ...J.. ____ -L... ____ -':-__ ~
0.
0 1 2 3
4 5
Current aboveground
biomass increment (Mg ha- 1 yea(1)
Fig. 3.3. Relationships between net
aboveground primary production
and a litterfall (1985-1986) and b
current aboveground biomass increment (1985-1988), for 18 closedcanopy holm oak plots in the Torrent de la Mina catchment (Montseny)