But that last is a vital consideration when looking to convert easy-contour land to forestry, because planting p.radiata is a quick sure way to deplete nutrients and microbial carbon and leave soils good for not much else than re-planting pines.
Family-owned farms establishing forestry blocks will naturally do so on marginal land and leave more productive areas for pasture or other crops. But corporates, especially foreign-owned ones owing no allegiance to New Zealand values, just want to maximise returns; if they buy a property for forestry, forest is all they will grow.
Very few "hill country" farms are all hills. Typically most blocks of, say, 5-600 hectares or so include perhaps 80-100 hectares of river flats or similar – higher-quality land best suited to a wide range of other uses.
These pieces – apart from genuine plains country farms, which I suggest should never be converted - are being incrementally lost to forestry and, on a regional let alone national scale, that adds up to a lot of fertile soils being degraded, permanently.
Ironically, the solution may in large part lie with something the farming sector has fought long and hard until now to avoid – comprehensive landuse regulation.
Such regulation is slowly coming into being as regional councils improve their water and waste management plans in particular, forcing farmers to derive farm-specific plans – on a paddock-by-paddock basis - to suit, such as has recently occurred in the Tukituki catchment under the HBRC's Plan Change 6, or further south under Horizon's One Plan.
It's perfectly feasible for such regimes to extend to specify not only the maximum of what you can grow of anything on a given piece of land, but what you can't. Or at least, what you need a non-complying consent for.
That approach, instituted nationally, would not discourage the overseas / corporate investment which seems to be part of Government's intent, while encouraging buyers to lease out or sell off more productive parts of any "hill country" blocks for livestock or cropping or horticulture or viticulture, as applicable.
It would, of course, also put an end to nonsense at the other end of the spectrum, such as the current outbreak of vigilante protectionism over winter feedlots for cows in Southland.
There, cowboy farmers have been overstocking prime river flats and turning great swathes of the landscape into giant muddy bogs – and then aggressively intimidating anyone who dares protest.
Which makes it hard for someone like me to write in defence of stock farming. But it's the land I'm trying to defend, not some of the wanton idiots misusing it.