Interesting thread. I would like to share part of my experience and thoughts.
The area I live in has been various types of forests, and even a sea or ocean I think.
Humans are rather invasive I would say. Is there something wrong with that? now as humans we decide to disrupt the environ, in many unneeded ways. ants will spread far and wide, most species, even many types of plants, and trees fight to adapt to new areas, and or spread their seed in whatever form as far as possible.
ever look at a massive ant hill? I'm sure ants of all types are around, but where I live they appear to "weed" or de-seed or otherwise hinder growth of plants in a circle around their mound. they travel for food much much farther then this circle, so it doesnt seem to be in relation to food. Likely keep roots out of their area.
My point being as a living being I DO believe we have the right to alter the landscape to meet our needs. as humans we have a much greater potential for this then other species. Meaning we can do much better things then other can or much much worse.
What would humans living as true stewards look like?
Do you know humans have left deserts behind in many areas around the world? various issues caused this, but a big part of it is various relationships of water in the soils, water tables, how they relate to biomass then the climate. It seems as we alter, the land to support less and less, and other ways we let the soils slowly die, various trigger points can happen, over time making the area more and more arid, and barren.
For instance in africa now. the river was dammed, in general the soil does not retain water well, so it all goes to the river, flooding it greatly, and then the standing waters have a chance to sink in better, and hit the water tables which stretch much farther then the flooding. so this is throwing many many things out of whack over time, making already rough soils rougher and drier. Making the land retain even less water.
SO, they could take the damns off the rivers..... OR we could find ways to retain present water, which either runs to the river, then floods before it sinks in well, OR we could work to retain it on site.
In my area I read the soil retains only 50 percent of present water. Things I have read imply a simple thick mulch/organic matter, bedding can take water retention to 80 or 90 percent. Basically 60-80 percent more water.
Then we come to the fact nearly everything we eat in this country is not native. The problem is not non natives or even "invasives". It is things which throw the eco system out of whack or are so invasive they cant be controlled.
When I contemplate humans role in this amazing reality we find ourselves in, I come to the conclusion our very existence might be to be a hand in balancing the eco systems. Keeping things vibrant. stirring the compost heap from time to time. and DIRECTED seeding AND selecting of more desirable foods for man and beast. due to our inbalance within ourselves, relating to patterns we pass down through the generations, we cause a inbalance around us.
As someone starting to study plant breeding, and the humans selections of food through the ages, (I'm no "expert" but I have read many examples) we in very many cases selected, and bred partially out of ignorance, and indeed forever altered the course of many species for one. We also made many much harder to grow. In many cases we did NOT have to give up ease of growing (meaning wild or near so) for taste or even yield in many cases. What breeding offers is extremely broad and offers amazing potentialities.
I hit tons of topics here, but my intent was to start painting a picture of the scope of invasive, the idea nearly everything wants to be, and the thought WE along as far as we know, have the ability to cognizantly alter and divert the course of things. and ANY way we feed ourselves WILL alter things, unless we start hording nuts, and dried berries and bury them in holes like a chipmunk or something. even then we would be altering things anyway.