Observations made in spring after bud break. HREC 1986, 1987. Observations made in spring after bud break. The most important factor for reduction of moisture stress in seedling experiments has been weed control.
Shade provided by window screen cages is suspected of making an unmeasured positive contribution.
Interaction between weed control and protection develops over time. Of this voles were responsible for about two-thirds. The remainder, or about one-quarter of all mortality, was attributed to gophers. The IP weed control treatment appeared to aggravate the problem by providing cover for rodents and exposing the younger seedlings to greater damage. The accumulation of biomass created habitat that apparently attracted rodents, particularly voles, during an increase in natural populations.