actually alder wood is almost red when freshly cut -but it turns orange-yellow when dries (it pales even further when not stored in dry conditions)
actually it's not exactly true - it's the stumps that turn red after the tree has been cut - when freshly felled alder tree is very intensly orange with a bit of red hue - I guess the red coloring in the tree must come from the roots
Why?
if I knew what type of these were I could perhaps give you one reason why they were felled - why the stumps have been left so high is probably to allow off-road cars to be able to pull themselves out if they somehow manage to slide down the slope (most employees and contractors of Lasy Państwowe drive off-roads these days)
scratch that - I now think it pretty imposible even with the use of these stumps
maybe it's just to stop trailers from sliding off the road in muddier road condition