What are the disadvantages of tree plantation?

Answer 1

1) reduction of biodiversity

2) possible limitation of products that could be produced and market fluctuations for that product (if you're producing for a type of lumber, such as white pine, you can only produce the type(s) for the species you're growing, and what if the market demand for that type goes down?)

3) if the local conditions aren't suitable for the species you want to grow, it can be expensive to change the existing conditions (soil pH, need for irrigation)

4) if trees are all the same age, you have to wait possibly decades between harvests; if you plant an area at different times, your overall harvest and profit can be more frequent, but smaller

5) limiting the plantation to one species makes spread of pests/diseases of that species between trees easier