It's really simple guys. If the value of the forest to society is higher in it's natural state than it is in it's harvested state, the forest will be saved. It depends on the aggregate of the subjective values of all individuals. All the edge effects and biodiversity are factored in by the market.
No, all the factors are not factored in. The value between two parties is equivalent to who can pay what and what can often be earned in one lifetime. In general, a party is not going to pay more than what he believes he can derive near term.
Yeah, but prices are set by the market. What one party can "derive near term" depends on how the market values his resources, not just on his personal values. If biodiversity is valued by the market, then he can derive value from his resources as a biodiverse system. So the the values of the market are factored into the price.
Similarly, a coal mine only has value to the entrepreneur because the market values coal. So one may buy the land to mine the coal if it's profitable. Profit is the indicator that the markets values are being met.
All economic activity in a free society is just a reflection of the aggregate values of the market. With the state, it's a function of a tyrants values.
Why would an individual pay an amount equal to a value that factors in the rain forest's value to all of the future of humanity? He can't afford it, and the seller will be more than willing to lower the price until he is satisfied personally.
He wouldn't, he would only pay an amount based on what he may yield in return. What he may yield is a function of the markets values. If he can't find the capital for this investment, then clearly society doesn't value the rainforest enough for the proposed utilization.
Just because you personally might value it higher than the average market value per individual, doesn't mean you have the right to initiate force to impose your values on others. If you think people misrepresent the value of the rainforest then you are charged with the task of education; a non-violent solution to the problem.
Furthermore, in a fractured model of ownership, it's easy for one to justify his sale, and allow the others to share the burden of valuing their properties to the full environmental value.
It's not a burden to have a valuable asset. You're thinking in a collectivist mindset. If non-fractured forests are more valuable than fractured ones, the market will answer this demand. Again, edge effects are factored in by the market.