I challenge you to tell me which part of the northern boreal uplands ecosystem has been altered to the same degree as the rice producing areas in China by historical indigenous populations

But I never claimed anything like that. Only that if natural or pristine is defined by the absence of human impact, then natural and pristine does not exist. So reifying natural ecosystems as intrinsically good and human altered systems as degraded or unecological doesn't make sense. 'Nature' and 'natural' are crutches for the environmental movement; they are used to justify some normative beliefs and values as intrinsically good and others as intrinsically bad. As a self-identifying environmentalist, I try not to rely on arguments that depend on 'the way things would be without humans' and focus instead on 'the way things ought to be with both humans and non-humans interacting with each other'.

Anyway, my basic point is that you and I do not have enough information to gauge whether the landscape in the picture is harmful or negative to the larger ecological functioning of the ecosystem (locally, regionally, and/or globally). It is simplistic to state that because it has been significantly altered by human agency that it is inherently bad. It's certainly possible that the rice terraces have contributed to the biodiversity of the region (you will notice the variety of trees intercropped and the likelihood of many different rice varieties being planted) and it is possible that the rice terraces have had negative effects on the broader biodiversity of the region. It is impossible, however, to hold up this picture (as you originally did) as a quintessential example of how humans have reduced (as they often do--particularly in recent times) biodiversity and ecological integrity. Certainly it does not make sense to equate rice patties with copper retaining pools.

Of course I don't expect most people, and in particular most other environmentalists, to agree with me. But it's my worldview.

Edit: One last note (because all of 3 people will read this and care), I think my argument is important because writing off this landscape automatically as degraded or ecologically impaired makes it more difficult to discuss how this landscape can continue to be intensively managed as a human landscape and as an ecologically valuable landscape. If we automatically reject this picture as unnatural and un-pristine and, thus, unworthy of conservation then we allow the important ecological functions that it provides to disappear.