ch ing ▁on ▁land ▁that ▁the ▁forest ▁had ▁begun ▁to ▁rec laim . ▁This ▁def or est ation ▁presents ▁two ▁major ▁problems . ▁First , ▁the ▁Guinea - C ong ol ian ▁forest ▁system , ▁of ▁which ▁much ▁of ▁Ang ola ' s ▁for ests ▁are ▁a ▁part , ▁provides ▁carbon ▁se quest r ation ▁that ▁is ▁vital ▁to ▁efforts ▁to ▁reduce ▁net ▁green house ▁gas ▁em issions . ▁Second , ▁a ▁large ▁portion ▁of ▁the ▁population ▁lives ▁in ▁rural ▁areas ▁and ▁re lies ▁on ▁subs istence , ▁which ▁requires ▁a ▁health y ▁and ▁diverse ▁e cos ystem ▁to ▁support . ▁ ▁Th re aten ed ▁species ▁▁ ▁Ang ola ▁has ▁histor ically ▁been ▁home ▁to ▁a ▁large ▁number ▁of ▁African ▁bush ▁ele ph ants , ▁though ▁their ▁population ▁was ▁sever ely ▁dimin ished ▁during ▁the ▁civil ▁war . ▁Research ers ▁who ▁studied ▁the ▁ele ph ant ▁population ▁in ▁ 2 0 0 5 ▁found ▁their ▁numbers ▁to ▁be ▁increasing ▁as ▁a ▁reasonable ▁pace . ▁Between ▁ 2 0 0 6 ▁and ▁ 2 0 1 5 , ▁the ▁Ang olan ▁government ▁refused ▁to ▁allow ▁surve ys ▁of ▁ele ph ant ▁populations . ▁New ▁research ▁conducted ▁in ▁ 2 0 1 5 ▁revealed ▁a ▁ 2 1 % ▁decl ine ▁in ▁population ▁over ▁the ▁previous ▁ten ▁years , ▁likely ▁due ▁to ▁increased ▁po aching ▁and ▁human ▁habitat ▁enc ro achment . ▁ ▁The ▁giant ▁s able ▁ant el ope ▁is ▁a ▁major ▁national ▁symbol ▁of ▁Ang ola . ▁While ▁it ▁once ▁could ▁be