Treesearch

In forests, droughts can cause considerable tree stress, particularly when they coincide with periods of abnormally hot weather, i.e., heat waves (L.D.L. Anderegg and others 2013, Peters and others 2015, Williams and others 2013). Trees and other plants respond to this stress by restricting fundamental growth processes. Photosynthesis, which is less sensitive than other fundamental processes, decreases slowly at low levels of drought stress but decreases more rapidly as the stress becomes more severe (Kareiva and others 1993, Mattson and Haack 1987). Ultimately, prolonged drought stress...

The annual national report of the Forest Health Monitoring (FHM) program of the Forest Service, U.S. Department of Agriculture, presents forest health status and trends from a national or multi-State regional perspective using a variety of sources, introduces new techniques for analyzing forest health data, and summarizes results of recently completed Evaluation Monitoring projects funded through the FHM national program. In this 20th edition in a series of annual reports, national survey data are used to identify recent geographic patterns of insect and disease activity. Satellite data...

Forests and woodlands cover an extremely large area of the United States, 333 million ha or approximately 36 percent of the Nation’s land area (Oswalt and others 2019). These forests possess the capacity to provide a broad range of goods and services for current and future generations, to safeguard biological diversity, and to contribute to the resilience of ecosystems, societies, and economies (USDA Forest Service 2011). Their ecological roles include supplying large and consistent quantities of clean water, preventing soil erosion, and providing habitat for a broad diversity of plant and...

The San Dimas Experimental Forest (SDEF) is located in southern California and is representative of the chaparral shrublands of the Southwest USA. Chaparral – including genera of Ceanothus, Adenostoma, Quercus, Salviaand Arctostaphylos– is a dense, drought-tolerant vegetation assemblage with a closed canopy 3–5 m in height. Chaparral is a fire-prone ecosystem and wildfires have burned the SDEF about every 40 years. The SDEF was established in 1933 to quantify the water cycle in a steep, semiarid landscape. Study catchments range in size from 15 to 1160 ha and measurements of stream runoff...

This is 1 of 23 guides to help Southeastern U.S. producers of economically important agricultural commodities build resilience to, prepare for, and recover from hurricane impacts.

Excess N deposition is a common stressor of ecological health. Sensitive biota, including many lichens, respond to small differences in atmospheric N deposition. For lands with a conservation mandate, obtaining sufficient N data to evaluate risks is a challenge, especially in Mediterranean or arid landscapes. Managers in the Western U.S. commonly use epiphytic (“tree-dwelling”) lichens to supplement N assessments, although options for higher elevations lacking epiphytes are poorly developed. Managers instead rely on broad-scale air quality simulations like the Total Deposition Model...

Forest structure and composition regulate a range of ecosystem services, including biodiversity, water and nutrient cycling, and wood volume for resource extraction. Forest type is an important metric measured in the US Forest Service Forest Inventory and Analysis (FIA) program, the national forest inventory of the USA. Forest type information can be used to quantify carbon and other forest resources within specific domains to support ecological analysis and forest management decisions, such as managing for disease and pests. In this study, we developed a methodology that uses a combination...

Aggregate housing data were overwhelmingly positive in March. Total March housing starts achieved their greatest level since July 2006. Total and single-family permits rebounded strongly as well. Houses under construction and housing completions also attained their highest levels in 13 years. New single-family house sales recorded significant gains. Existing house sales were negative month-over-month, and housing doyens attributed this to a lack of inventory. Total and single-family construction spending were positive month-over-month and year-over-year. In sum, private residential...

The year-over-year housing data for April were all robustly positive. However, month-over-month declines were reported for total and single-family housing starts, total and single-family permits, total housing completions, and new single-family and existing house sales. Total and single-family houses under construction and total and single-family construction spending were positive month-over-month.