Behind the general pattern of forest loss and gain: A long-term assessment of semi-natural and secondary forest cover change at country level

Abstract

Despite deforestation taking place globally, forest cover is increasing in many European landscapes. This increase, however, resulting from plantations and spontaneous forest regrowth, may obscure the generally declining trend of semi-natural forests, though the latter are essential for local and landscape-level conservation strategies and sustainable forest management. We assessed changes in semi-natural and secondary forest cover since the 18th century in Hungary, focusing on the continuity of semi-natural forests. The main trajectories of regional and country-scale forest transformations were reconstructed from the fine-scale site histories of 1,728 randomly selected sample localities. Historical and recent datasets were complemented with field data to estimate forest cover change for seven time periods between the 1780s and the 2010s. Total forest cover changes over these 230 years showed a U-shape curve (from 25% to 24%), leading to a forest minimum in the first half of the 20th century. Semi-natural and secondary forests exhibited strikingly different trends. The proportion of semi-natural forests decreased to 36% of the total forest area by the 2010s, driven mainly by conversion to arable land, while 88% of the actual semi-natural forests have remained continuous forest since the 18th century. Our results showed that when reconstructing landscape-scale historical forest cover change and continuity, the loss of semi-natural forests remains hidden if the calculations are limited to ‘total forest cover change’. It would therefore be immensely important to distinguish between semi-natural and secondary forests, and between types of continuity in the assessments used for conservation-oriented landscape planning and sustainable forest management.