摘要
Canopy density and forest biomass estimation </span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">are</span></span></span><span><span><span style="font-family:""><span style="font-family:Verdana;"> critical for </span><span style="font-family:Verdana;">understanding</span> <span style="font-family:Verdana;">of</span><span style="font-family:Verdana;"> the carbon cycle, climate change </span><span style="font-family:Verdana;">and</span><span style="font-family:Verdana;"> detecting </span><span style="font-family:Verdana;">health</span><span style="font-family:Verdana;"> status of the forest ecosystems. This study was conducted on the coastal </span><span style="font-family:Verdana;">forests</span><span style="font-family:Verdana;"> reserves in Zanzibar and mainland Tanzania. A systematic sampling design was used to establish a total of 110 temporary sample plots in all study sites. The stratification of the forests was adopted to identify closed </span><span style="font-family:Verdana;">forest</span><span style="font-family:Verdana;"> patches with less anthropogenic effects. The study assessed the forest canopy density and above ground biomass with relative carbon stock for closed forest classes. Jozani Chwaka Bay National Park in Zanzibar recorded higher average canopy densities of 63% followed by Ngezi (46%), Pugu forests (26%) </span><span style="font-family:Verdana;">and</span><span style="font-family:Verdana;"> Kazimzumbwi (16%). However, </span><span style="font-family:Verdana;">Ngezi</span><span style="font-family:Verdana;"> forest had higher forest biomass than all study sites with </span><span style="font-family:Verdana;">the overall</span><span style="font-family:Verdana;"> mean AGB of 138.5 </span><span style="font-family:Verdana;">tAGB</span><span style="font-family:Verdana;">/ha equivalent to carbon stock of 67.9 tC/ha. Tree species, </span><i><span style="font-family:Verdana;">Bombax</span></i> <i><span style="font-family:Verdana;">rhodognaphala</span></i><span style="font-family:Verdana;"> (Msufi </span><span style="font-family:Verdana;">mwitu</span><span style="font-family:Verdana;">) and </span><i><span style="font-family:Verdana;">Antiaris</span></i> <i><span style="font-family:Verdana;">toxicaria</span></i><span style="font-family:Verdana;"> (Mgulele) recorded </span></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">the </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">highest biomass of 1099</span></span></span><span><span><span style="font-family:""> </span></span></span><span><span><span style="font-family:""><span style="font-family:Verdana;">tABG/ha and 703 </span><span style="font-family:Verdana;">tAGB</span><span style="font-family:Verdana;">/ha (equivalent to 538 </span><span style="font-family:Verdana;">tC</span><span style="font-family:Verdana;">/ha and (345 tC/ha)</span></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">)</span></span></span><span><span><span style="font-family:""><span style="font-family:Verdana;"> respectively. The study revealed that about 35% of the total closed forest patches at Pugu FR </span><span style="font-family:Verdana;">w</span></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">ere</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> covered by lower canopy density which accounted about 490 ha. Kazimzumbwi FR was dominated by lower canopy density which represented about 64% of the total forest cover area (1750 ha).
Canopy density and forest biomass estimation </span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">are</span></span></span><span><span><span style="font-family:""><span style="font-family:Verdana;"> critical for </span><span style="font-family:Verdana;">understanding</span> <span style="font-family:Verdana;">of</span><span style="font-family:Verdana;"> the carbon cycle, climate change </span><span style="font-family:Verdana;">and</span><span style="font-family:Verdana;"> detecting </span><span style="font-family:Verdana;">health</span><span style="font-family:Verdana;"> status of the forest ecosystems. This study was conducted on the coastal </span><span style="font-family:Verdana;">forests</span><span style="font-family:Verdana;"> reserves in Zanzibar and mainland Tanzania. A systematic sampling design was used to establish a total of 110 temporary sample plots in all study sites. The stratification of the forests was adopted to identify closed </span><span style="font-family:Verdana;">forest</span><span style="font-family:Verdana;"> patches with less anthropogenic effects. The study assessed the forest canopy density and above ground biomass with relative carbon stock for closed forest classes. Jozani Chwaka Bay National Park in Zanzibar recorded higher average canopy densities of 63% followed by Ngezi (46%), Pugu forests (26%) </span><span style="font-family:Verdana;">and</span><span style="font-family:Verdana;"> Kazimzumbwi (16%). However, </span><span style="font-family:Verdana;">Ngezi</span><span style="font-family:Verdana;"> forest had higher forest biomass than all study sites with </span><span style="font-family:Verdana;">the overall</span><span style="font-family:Verdana;"> mean AGB of 138.5 </span><span style="font-family:Verdana;">tAGB</span><span style="font-family:Verdana;">/ha equivalent to carbon stock of 67.9 tC/ha. Tree species, </span><i><span style="font-family:Verdana;">Bombax</span></i> <i><span style="font-family:Verdana;">rhodognaphala</span></i><span style="font-family:Verdana;"> (Msufi </span><span style="font-family:Verdana;">mwitu</span><span style="font-family:Verdana;">) and </span><i><span style="font-family:Verdana;">Antiaris</span></i> <i><span style="font-family:Verdana;">toxicaria</span></i><span style="font-family:Verdana;"> (Mgulele) recorded </span></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">the </span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">highest biomass of 1099</span></span></span><span><span><span style="font-family:""> </span></span></span><span><span><span style="font-family:""><span style="font-family:Verdana;">tABG/ha and 703 </span><span style="font-family:Verdana;">tAGB</span><span style="font-family:Verdana;">/ha (equivalent to 538 </span><span style="font-family:Verdana;">tC</span><span style="font-family:Verdana;">/ha and (345 tC/ha)</span></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">)</span></span></span><span><span><span style="font-family:""><span style="font-family:Verdana;"> respectively. The study revealed that about 35% of the total closed forest patches at Pugu FR </span><span style="font-family:Verdana;">w</span></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">ere</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"> covered by lower canopy density which accounted about 490 ha. Kazimzumbwi FR was dominated by lower canopy density which represented about 64% of the total forest cover area (1750 ha).
作者
Iddi H. Hassan
Makarius V. Mdemu
Iddi H. Hassan;Makarius V. Mdemu(Department Name of Natural Sciences, The State University of Zanzibar & Zanzibar Commission for Lands, Zanzibar, Tanzania;School of Spatial Planning and Social Sciences, Ardhi University, Dar es Salaam, Tanzania)
