The dynamics of carbon accumulation in Eucalyptus and Acacia plantations in the Pearl River delta region

Abstract

<b><i>Key message </i></b><b>Plantation</b><b> type and age strongly influence the
quantity of carbon stored in forest ecosystems. </b><b>The marked increase in total ecosystem carbon
stock achieved over time by the <i>Eucalyptus</i>
and <i>Acacia</i> plantations has confirmed
that the afforestation of degraded soils can contribute positively to carbon
sequestration.</b><b> </b><b></b>

·<b><i>Context</i></b> Reforestation has been widely conducted to
restore and protect the eroded red soil in south China in recent decades. The
question as to whether the content of soil organic carbon (SOC) can be
boosted by establishing plantations of fast-growing tree species remains unresolved.

<b><i>·</i></b><b><i>Aim </i></b>We addressed whether the afforestation of
degraded soils can contribute positively to carbon sequestration, and whether
the accumulation of SOC is more effective under a nitrogen fixing species such
as <i>Acacia</i> than under <i>Eucalyptus</i>.

·<b><i>Methods</i></b> Here, a
study was undertaken to measure the quantity of total ecosystem carbon (TEC)
accumulated by plantations of both <i>Eucalyptus
</i>and<i> Acacia</i> spp. in the Pearl
River Delta region of southern China.

·<b><i>Results </i></b>The quantity
of TEC increased significantly with stand age in both plantation types (<i>P</i> &lt; 0.05). The largest single
component of TEC was SOC, with stand age having a considerable effect on both
SOC and overall biomass. The accumulation of SOC in the top 100 cm of the soil
profile was higher under <i>Acacia</i> than
under <i>Eucalyptus</i> (<i>P </i>&lt; 0.05). <b></b>

·<b><i>Conclusion </i></b>In
terms of carbon sequestration, the afforestation of <i>Eucalyptus </i>and<i> Acacia</i> represent an effective forest management practice. The accumulation of SOC
is more effective under <i>Acacia</i> than
under <i>Eucalyptus</i><b></b>