How would reducing low growing plants from an area impact a population of tortoises with two varieties of neck extension ability: short and long-distance?

The proportion of tortoises that could only extend their next a short distance would increase
The variety of tortoises that could only extend their next a short distance would go extinct
The proportion of tortoises, with the ability to extend their long distance would increase
The variety of tortoises with the ability to extend their necks. A long distance would go extinct.

The proportion of tortoises that could only extend their neck a short distance would increase because they would have less competition for food with the low growing plants reduced. This could potentially lead to an increase in the overall population of tortoises with short neck extension ability.

On the other hand, the variety of tortoises that could only extend their neck a short distance may become dominant and potentially outcompete the variety with long-distance neck extension ability. This could lead to the extinction of the long-distance neck extension variety of tortoises.

Therefore, reducing low growing plants from an area could have a negative impact on the population and variety of tortoises with long-distance neck extension ability.