The max tree-height of an undirected graph is the longest possible length of a path among all spanning trees of the graph. A maximum height spanning tree of an undirected graph is a spanning tree that has a path of length equal to the max tree-height of the graph. Finding the max tree-height of a graph, or similarly some spanning tree of maximum height, is an NP-hard optimization problem for wh...

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...

Container-grown quiescent Douglas-fir (Pseudotsuga menziesii var. glauca (Beissn.) Franco) seedlings were air dried to plant water potentials of -0.2, -2.2 or -3.8 MPa (unstressed, moderate, and severe stress treatments, respectively). Trees from each treatment were either placed in root mist chambers held at 10, 20, or 28 degrees C for 28 days and root growth potential (RGP) and plant water po...

The characteristic decline in height growth that occurs over a tree's lifespan is often called "age-related decline." But is the reduction in height growth in aging trees a function of age or of size? We grafted shoot tips across different ages and sizes of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) trees to determine whether the decline in height growth is mediated by tree size or by t...

Constraint search trees are a generic approach to search trees where all operations are defined in terms of constraints. This abstract viewpoint makes clear the fundamental operations of search trees and immediately points to new possibilities for search trees. In this paper we present height-balanced constraint search trees (HCSTs), a general approach to building height-balanced index structur...

We introduce a weighted model of random trees and analyze the asymptotic properties of their heights. Our framework encompasses most trees of logarithmic height that were introduced in the context of the analysis of algorithms or combinatorics. This allows us to state a sort of“master theorem”for the height of random trees, that covers binary search trees (Devroye, 1986), random recursive trees...

In this paper we introduce a class of trees, called generalized compressed trees. Generalized compressed trees can be derived from complete binary trees by performing certain `contraction' operations. A generalized compressed tree CT of height h has approximately 25% fewer nodes than a complete binary tree T of height h. We show that these trees have smaller (up to a 74% reduction) 2-dimensiona...

Due to expected climate change and increased focus on forests as a potential carbon sink, it is of interest to map and monitor even marginal forests where trees exist close to their tolerance limits, such as small pioneer trees in the forest-tundra ecotone. Such small trees might indicate tree line migrations and expansion of the forests into treeless areas. Airborne laser scanning (ALS) has be...