In some cases it's prudent to set aside land for nature. Such land use extends beyond aesthetics or recreation. I have a minor issue with the term "open space" because it may imply that it is idle or underutilized land. Instead, open spaces are well appropriated and irreplaceable. These lands harbor unique habitats and species.
Just like our history, culture and commerce, nature in the Willamette Valley is special and like nothing else on Earth. Without open spaces (both public and private) set aside to retain what little natural ecosystems we have left, our identity as a community is threatened. Open spaces protect and support commerce by improving the quality of life and increasing the desire for people to live, work and do business here. Open spaces also have innate economic benefits, including but not limited to, enhancing water quality and reducing erosion. Recent open space acquisitions and potential new ones like Witham Oaks are mere specs on the map, vastly outnumbered by human development and farms.
I must make it clear that I advocate keeping our land largely utilized by development and agriculture. But it's not too much to ask that a few spaces here and there be kept out of that process.