Treesearch

Machine learning approaches such as random forest have increased for the spatial modeling and mapping of continuous variables. Random forest is a non-parametric ensemble approach, and unlike traditional regression approaches there is no direct quantification of prediction error. Understanding prediction uncertainty is important when using model-based continuous maps as inputs to other modeling applications such as fire modeling. Here we use a Monte Carlo approach to quantify prediction uncertainty for random forest regression models. We test the approach by simulating maps of dependent and...

Forests are a crucial element not only of landscapes but also of human living conditions. Covering nearly a third of the earth's land surtace, they stabilize surface soil, prevent erosion and play an essential role in water resource management at the watershed and local levels. They regulate climate and improve air quality. At the same time they are an important resource for the regional economy (wood production, recreation and tourism) and are an important cultural and social heritage of the local and regional human activities. They provide habitats for a multitude of animal and plant...

Characterizing forest soil properties with high variability is challenging, sometimes requiring large numbers of soil samples. Soil bulk density is a standard variable needed along with element concentrations to calculate nutrient pools. This study aimed to determine the optimal sample size, the number of observation (n), for predicting the soil bulk density with a precision of ±10% at a 95% confidence level among different soil types. We determined soil bulk density samples at three depths at 186 points distributed over three different 1-ha forest sites. We calculated n needed for...

Future forests are being shaped by changing climate and disturbances. Climate change is causing large-scale forest declines globally, in addition to distributional shifts of many tree species. Because environmental cues dictate insect seasonality and population success, climate change is also influencing tree-killing bark beetles. The mountain pine beetle, Dendroctonus ponderosae, is a major disturbance in Pinus forests of the western US. Using a mechanistic, phenology-based demographic model driven by downscaled daily temperature data, we describe recent and future spatial and temporal...

Studies of land surface dynamics in heterogeneous landscapes often require remote sensing datawith high acquisition frequency and high spatial resolution. However, no single sensor meets this requirement. This study presents a new spatiotemporal data fusion method, the Flexible Spatiotemporal DAta Fusion (FSDAF) method, to generate synthesized frequent high spatial resolution images through blending two types of data, i.e., frequent coarse spatial resolution data, such as that from MODIS, and less frequent high spatial resolution data such as that from Landsat. The proposed method is based...

We synthesize insights from current understanding of drought impacts at stand-to-biogeographic scales, including management options, and we identify challenges to be addressed with new research. Large stand-level shifts underway in western forests already are showing the importance of interactions involving drought, insects, and fire. Diebacks, changes in composition and structure, and shifting range limits are widely observed. In the eastern US, the effects of increasing drought are becoming better understood at the level of individual trees, but this knowledge cannot yet be confidently...

Glossary of Forest Futures of the Northern United States.

Appendices in Future forests of the northern United States.

Tree fertilization is a common service provided by commercial arborists and landscapers. Customers and clients are familiar with fertilization from the care of house or garden plants. Any hardware or garden supply store has attractive packages of colored crystals or liquid solutions that promise rapid growth and abundant blossoms. This familiarity with fertilization of annual or herbaceous perennial plants is extended by the public to the care of landscape trees. Of course fertilization is a common service!

This periodic resource update provides an overview of forest resources in Florida based on an inventory conducted by the U.S. Forest Service, Forest Inventory and Analysis (FIA) program at the Southern Research Station in cooperation with the Florida Forest Service. Estimates are based on field data collected using the FIA annualized sample design and are updated yearly. The estimates presented in this update are for the measurement year 2013, with comparisons made to data reported in 2007. The sample plot population in Florida consists of 7,089 plots distributed across the State, of which...