<prompt> Bheka isigaba esingezansi bese uphendula umbuzo emva kwalokho ngolimi olufanayo nesigaba: Ukudlula: Kusukela ngo-1972, iNational Park Service yaqala ukuvumela imililo yemvelo eYellowstone ukuba ivuthe ngaphansi kwezimo ezilawulwayo. Imililo yalolu hlobo yayibizwa ngokuthi imililo yemvelo enqunyiwe. Phakathi kuka-1972 no-1987, ingqikithi yemililo yemvelo ebekiwe engu-235 yashisa indawo encane engamahektare angu-33.759 137 km2 ngaphansi kweziqondiso zenqubomgomo entsha. Kulezi, ezingu - 15 kuphela ezazisakazeke ngaphezu kwamahektare angu - 100 amakhilomitha angu - 0,4. Iminyaka emihlanu yangaphambi kuka-1988 yayina kakhulu kunokujwayelekile futhi lokhu kungenzeka kwanciphisa indawo yemililo phakathi naleso sikhathi. Inqubomgomo yemililo yemvelo ebekiwe yabonakala iyindlela ephumelelayo yokulawula imililo, ikakhulukazi esifundeni saseYellowstone. Umbuzo: Imililo yemvelo ebekiwe yasetshenziswa kuyiphi ipaki?  <response>: I-Yellowstone 