Fire played an important role in maintaining and creating conditions suitable for native flora and fauna in the forests of western North America. Recent coarse filter conservation strategies have advocated creating future landscapes that incorporate historic or natural ranges of variability, including fire regimes. Historic fire regimes were variable across the West, and created quite unique co...

Huffman’s algorithm is a procedure for constructing a binary tree with minimum weighted path length. This report presents a formal proof of the correctness of Huffman’s algorithm written using Isabelle/HOL. Our proof closely follows the sketches found in standard algorithms textbooks, uncovering a few snags in the process. Another distinguishing feature of our formalization is the use of custom...

Standing dead trees, or snags, serve myriad functions in natural forests, but are often scarce forests managed for timber production. Variable retention (VR), the of live and trees through harvest, has been adopted globally as a less intensive form regeneration harvest. In this study, we explore how two key elements VR systems — level (amount) spatial pattern live-tree affect carryover post-har...

the evaluation of ecological characteristics of wildlife species has fundamental role in species management, because taking a decision for proper method of management is only possible by characterizing of ecological requirements of a species. in this study, suitable habitat of middle spotted woodpecker was investigated in golestan national park. presence and absence of birds and environmental v...