Complex sentence: The repeal of old regulations will put currently conserved land at risk: future perceived threats to conserved lands and resources might not be able to be stopped since the erasure of regulation that sought to combat past threats to conserved lands may be eliminated.
Split into simpler sentences: The repeal of old regulations will put currently conserved land at risk. Furthermore, future perceived threats to conserved lands and resources might not be able to be stopped for the erasure of regulation that sought to combat past threats to conserved lands may be eliminated.