Soil Compaction and Productivity Evolution in a Harvested and Grazed Mediterranean Scots Pine (Pinus sylvestris L.) Forest

Abstract

The effects of machinery and livestock on forest soil compaction have mostly been studied at short-term and local scales. A better understanding of the long-term effects of compaction in mature stands at the management scale is needed, especially in hot and dry climates. This study aims to analyze (1) soil compaction in a Mediterranean Scots pine (Pinus sylvestris L.) forest subjected to mechanized logging and grazing for more than 50 years and (2) forest productivity trends during these 50 years of disturbance. Soil penetration resistance (0–10 cm and 10–20 cm) and soil moisture (0–12 cm) were measured in 181 randomly selected points affected by “high machinery traffic”, “high cattle traffic” or “low traffic”. Decennial forest inventory data on density, timber volume, and recruitment were collected and analyzed over the five decades preceding soil measurements. Soil penetration resistance exceeded 2500 kPa at a significant portion of the sampled points, although the highest levels of compaction tended to be concentrated in the subsurface layer of the high-traffic areas. Cattle and machinery caused significant compaction in these areas and increased penetration resistance in the range of 350–450 kPa. However, despite the long period of disturbance and the increase in penetration resistance observed, no signs of productivity decline were detected in the forest.

The Effects of Soil Compaction on the Growth and Architecture of the Seedlings of Species Commonly Used for Afforestation in Iran

“…The soil texture was not changed in this study. However, the effects of soil texture on root growth could be primarily interpreted according to the differences in air, water, and strength of soil between textures [46,[54][55][56][57][58][59][60][61]. In this study, the seedling pots were irrigated regularly daily and did not experience any water deficit.…”

Soil Compaction Induced by Three Timber Extraction Options: A Controlled Experiment on Penetration Resistance on Silty-Loamy Soils

“…There are many ways and methods used to estimate the soil compaction severity [16][17][18], of which measuring the penetration resistance has become a widely accepted and used method in forest operations research (e.g., Refs. [19][20][21][22][23]) due to the simplicity of setting and implementing the experimental designs and affordability in terms of money, time and other resources spent to collect, process and analyze the required data. However, the method only provides indicative figures on soil compaction state, since it measures the strength of the soil instead of actual bulk density.…”