Treesearch

High-resolution biogenic and geologic proxies in which one increment or layer is formed per year are crucial to describing natural ranges of environmental variability in Earth's physical and biological systems. However, dating controls are necessary to ensure temporal precision and accuracy; simple counts cannot ensure that all layers are placed correctly in time. Originally developed for tree-ring data, crossdating is the only such procedure that ensures all increments have been assigned the correct calendar year of formation. Here, we use growth-increment data from two tree species, two...

Laurel wilt, caused by Raffaelea lauricola T.C.Harr., Aghayeva, & Fraedrich, a fungal symbiont of the redbay ambrosia beetle (Xyleborus glabratus Eichhoff), is responsible for extensive mortality of redbay (Persea borbonia (L.) Spreng) and other Lauraceae native to the United States (Fraedrich et al. 2008). The beetle and fungus were introduced into the United States near Savannah, GA, from Asia around 2000, and since then the disease has been spreading rapidly through the southern United States. In March 2015 dead and dying redbay trees were observed in Hardin County, TX, in an area...

Rainfall erosivity is an important factor for estimating soil erosion rates. Understanding the spatial distributionand temporal trends of rainfall erosivity is especially critical for soil erosion risk assessment and soil conservationplanning in mainland China. However, reports on the spatial distribution and temporal trends of rainfall erosivityfor China, especially of its eight soil erosion regions, are still lacking, which reduces the accuracy of predicting soillosses, assessing soil erosion risks and evaluating the effects of soil conservation measures. Additionally, the lackof the...

1. Woody plant encroachment of grasslands is occurring globally, with profound ecological consequences. Attempts to restore herbaceous dominance may fail if the woody state is resilient or if intervention leads to an alternate, undesirable state. Restoration outcomes often hinge on biotic interactions – particularly on priority effects that inhibit or promote community reassembly. 2. Following experimental tree removal from conifer-invaded grasslands, we documented substantial variation in community reassembly associated with the changing abundance of the native clonal sedge Carex inops...

Remote sensing for hazard response requires a priori identification of sensor, transmission, processing, and distribution methods to permit the extraction of relevant information in timescales sufficient to allow managers to make a given time-sensitive decision. This study applies and demonstrates the utility of the Remote Sensing Communication Model (RSCM) to improve a tactical wildfire remote-sensing system to better meet the time-sensitive information requirements of emergency response managers in San Diego County, USA. A thermal infrared airborne remote-sensing system designed and...

Bioeconomic models are idealized representations of human-nature interactions used to describe how the decisions that people make regarding the harvest of biological resources affect the future condition of resource stocks and the flow of net economic benefits. This modeling approach posits an assumed goal or objective that a decision-maker seeks to optimize subject to a set of biological constraints. The power of this method derives from its ability to evaluate a wide array of alternative policy or management innovations over timescales that are radically longer than the timescales...

A population of Xiphinema chambersi from the root zone around live oak (Quercus virginiana Mill.) trees on Jekyll Island, GA, is described using both morphological and molecular tools and compared with descriptions of type specimens. Initially, because of a few morphological differences, this nematode was thought to represent an undescribed species. However, on further examination, the morphometrics of the nematodes from live oak tend to agree with most of the morphometrics in the original description and redescription of X. chambersi except for few minor differences in V% relative to body...

Wildfire risk in temperate forests has become a nearly intractable problem that can be characterized as a socioecological “pathology”: that is, a set of complex and problematic interactions among social and ecological systems across multiple spatial and temporal scales. Assessments of wildfire risk could benefit from recognizing and accounting for these interactions in terms of socioecological systems, also known as coupled natural and human systems (CNHS). We characterize the primary social and ecological dimensions of the wildfire risk pathology, paying particular attention to the...

For thousands of years, humans have created different types of terraces in different sloping conditions, meant to mitigate flood risks, reduce soil erosion and conserve water. These anthropogenic landscapes can be found in tropical and subtropical rainforests, deserts, and arid and semiarid mountains across the globe. Despite the long history, the roles of and the mechanisms by which terracing improves ecosystem services (ESs) remain poorly understood. Using literature synthesis and quantitative analysis, the worldwide types, distributions, major benefits and issues of terracing are...

Concern regarding extensive damage to tropical forests resulting from logging increased dramatically after World War II when mechanized logging systems developed in industrialized countries were deployed in the tropics. As a consequence, tropical foresters began developing logging procedures that were more environmentally benign, and by the 1990s, these practices began to be described as reduced impact logging” (RIL) systems. As scientific evidence accumulated demonstrating that RIL techniques could substantially reduce logging impacts on the residual forest relative to conventional...