Environmental Engineering Reference
In-Depth Information
Fig. 7.1
Modi
cation of
the timing of aphelion and
perihelion over time
The alteration of temperature and incoming
solar radiation has profound in
However, the incidence of extreme cold events is
not likely to be a factor limiting mangrove
expansion to higher latitudes in response to
increased surface temperature. The Intergovern-
mental Panel on Climate Change projects reduced
extreme cold events (Solomon et al.
2007
), in
correlation with projected changes in average
surface
uence on the
distribution pattern and species diversity of
coastal vegetation. Increased surface temperature
is expected to affect mangroves (Field
1995
;
Ellison
2000
)by:
1. changing species composition;
2. changing phenological patterns (e.g. timing of
fl
fl
temperatures. For
instance, Vavrus
owering and fruiting);
3. increasing mangrove
et al. (
2006
) predicted a 50
100 % decline in the
frequency of extreme cold air events in Northern
Hemisphere winter in most areas, while Meehl
et al. (
2004
) projected decreases in frost days in
the extratropics, where the pattern of decreases
will be determined by changes in atmospheric
circulation.
The effect of temperature
-
productivity where
temperature does not
exceed an upper
threshold; and
4. expanding mangrove ranges to higher lati-
tudes where range is limited by temperature,
but is not limited by other factors, including a
supply of propagules and suitable physio-
graphic conditions.
Mangroves reach a latitudinal limit at the 16
fl
uctuation due to
variation in the Earth
s orbit is explained here
with mangroves, but for all the species under the
domain of blue carbon the impact is consider-
able. The reproductive biology of seagrass spe-
cies has attracted naturalists for about two
centuries. Flowering of seagrasses is primarily
controlled by temperature and often occurs
simultaneously across large spatial scales. Euro-
pean seagrass species
'
C
isotherm for air temperature of the coldest month,
and the margins of incidence of ground frost,
where water temperatures do not exceed 24
°
C
(Ellison
2000
). The optimum mangrove leaf
temperature for photosynthesis is believed to be
between 28 and 32
°
C, while photosynthesis
ceases when leaf temperatures reach 38
°
C
(Clough et al.
1982
; Andrews et al.
1984
). The
frequency, duration and intensity of extreme cold
events have been hypothesized to explain the
current latitudinal limits of mangrove distribution
(Woodroffe and Grindrod
1991
; Snedaker
1995
).
40
°
fl
ower in late spring, and
-
some of
spp.) throughout the
summer as well, when irradiance improves and
water
them (
Zostera
temperature increases, except
for
the
Mediterranean
species
Posidonia
oceanica
,
which
fl
owers in the fall (October).
