What happened to the White Pine seedlings?

To study the relationship between fertilizer and deer browsing of white pines, we planted 140 blister rust resistant seedlings in 7 plots on MPG North in early June, 2009 (map, inset). A September 9, 2009 survey reported that >90% of the seedlings survived their first summer, but only 13 seedlings (about 10%) survived until our last survey in early June, 2010. This high mortality was unexpected. We think that the unusual cold snap last October killed these seedlings.