The centrally-located region is not immediately affected by the threat of desertification.

The centrally-located rain forests are not directly affected by the threat of desertification.

Explanation:

Desertification is a type of degrading lands where area of land loses its water bodies, vegetation and wildlife. This is by overexploitation of soil by humans through release of chemicals from industries, global warming which is a major cause for climate change. These are the results of geo-political and socio-economic conditions. This has become the major issue in sub-Sahara region of Africa and the borders of Southern edge of Africa. The centrally located regions are not immediately affected.  

Connecticut, delaware, maryland, massachusetts, new jersey, new york, new hampshire, north carolina, pennsylvania, rhode island, south carolina, virginia

So  if  the sum of the enthalpies of the reactants is greater than the products, the  reaction  will be  exothermic.  if  the products side has a larger enthalpy, the  reaction  is  endothermic. you may wonder why  endothermic reactions, which soak up energy or enthalpy from the environment, even happen