Environmental impact in building a new frontier

A three years research project along the plain section of the Roman frontier known as Limes Transalutanus has reached some peculiar conclusions. Between them one can count the fact that some sectors, summing three quarters of length of the northern section, although crossing open fields, has no obvious frontier obstacle. The common explanation, about ‘the state of art’, does not work this time, therefore one will need a rationale for that ‘anomaly’. The Romanian Plain of today is one of the most disfigured territories, due to the socialist exploitation of the land (mainly by draining and deforestations); consequently, it is impossible to make a historical assessment only on things today visible in the landscape. I tried to use all resources at hand, beginning with medieval documents and pursuing with cartographic depictions of several generations, place names and pedology, as much as an archaeologist can deal with them. The final answer is far simpler than expected: not all the sectors of the frontier were closed by manmade obstacles, because they were already secured by natural items, either thick forests or unexplored marshes. The only needed proof for a Roman boundary is the road running along the frontier, but this is difficult to prove on a field completely devoid of stone. I am suggesting also wooded barriers made of cut trees left on the spot, but such an obstacle leaves no archaeological traces.