Treesearch

This letter reports the sensitivity of X-band interferometric synthetic aperture radar (InSAR) data from the first dual-spacecraft radar interferometer, TanDEM-X, to variations in tropical-forest aboveground biomass (AGB). It also reports the first tropical-forest AGB estimates fromTanDEM-X data. Tropical forests account for about 50% of the world’s forested biomass and play critical roles in the control of atmospheric carbon dioxide by emission through deforestation and uptake through forest growth. The TanDEM-X InSAR data used in this analysis were taken over the Tapajós National Forest,...

Regenerating oaks (Quercus spp.) has remained a widespread and persistent problem throughout their natural range. Research shows that abundant oak advance reproduction is crucial for success. Although it is recognized that oak advance reproduction accumulation is inversely related to site quality, there has been little effort to model oak advance reproduction density as a function of measured levels of light, water, or nutrient supply. The objective of this study was to determine whether oak advance reproduction could be modeled and mapped with site variables. The study was conducted on...

Native to China and Korea, the Asian longhorned beetle, Anoplophora glabripennis (Motschulsky) (Coleoptera: Cerambycidae), is a polyphagous wood-boring pest for which a trapping system would greatly benefit eradication and management programs in both the introduced and native ranges. Over two field seasons, a total of 160 flight intercept panel traps were deployed in Harbin, China, which trapped a total of 65 beetles. In 2012, traps using lures with a 1:1 ratio of the male-produced pheromone components (4-(n-heptyloxy)butanal and 4-(n-heptyloxy)butan-1-ol) designed to release at a rate of...

This publication is a substantial revision of FHTET 2001-03, Hemlock Woolly Adelgid, which was published in 2001. This publication contains information on the native range of hemlock and range of hemlock woolly adelgid, the importance of hemlocks in eastern forest ecosystems, and on hosts, life cycle, control, and population trends of the hemlock woolly adelgid.

Putatively blight-resistant advanced backcross chestnut seedlings will soon be available for outplanting on a regional scale. Few studies have examined the importance of silvicultural treatment or seedling quality to chestnut reintroduction in the U.S. This paper examines results from a silvicultural study of high-quality chestnut seedlings on the Cumberland Plateau of southeastern Kentucky. Three hundred American (Castanea dentata), three hundred advanced backcross (BC2F3) and one hundred fifty Chinese chestnut (Castanea mollissima) seedlings were planted in three silvicultural treatments,...

American chestnut restoration depends on a multitude of biological, administrative, and technological factors. Germplasm traditionally bred for resistance to the chestnut blight disease caused by the exotic pathogen Cryphonectria parasitica has been deployed on national forests in the Eastern and Southern Regions of the National Forest System (NFS) since 2009. Trees were challenged by biological factors, primarily deer browse and ink disease (caused by Phytophthora cinnamomi). Because of these problems, inferences regarding resistance or tolerance to blight are premature. Mitigation to...

Laricobius osakensis (Coleoptera: Derodontidae) was imported from Japan to the United States in 2006 for study in quarantine facilities as a potential biological control of Hemlock Woolly Adelgid. Laricobius osakensis was released from quarantine in 2010, but it was soon discovered that the colony also contained a cryptic species, Laricobius naganoensis. This led to the placement of L. osakensis back into quarantine and development of a method to purify the colony. To distinguish the two species, we designed a restriction fragment length polymorphism (RFLP) assay using mitochondrial DNA...

Alien grass invasions in arid and semi-arid ecosystems are resulting in grass-fire cycles and ecosystem-level transformations that severely diminish ecosystem services. Our capacity to address the rapid and complex changes occurring in these ecosystems can be enhanced by developing an understanding of the environmental factors and ecosystem attributes that determine resilience of native ecosystems to stress and disturbance, and resistance to invasion. Cold desert shrublands occur over strong environmental gradients and exhibit significant differences in resilience and resistance. They...

The purpose of this study was to evaluate biochar as a substitute for vermiculite in potting mixes for unrooted vegetative cuttings of hybrid poplar as represented by the clone ‘NM6’ (Populus nigra L. × Populus suaveolens Fischer subsp. maximowiczii A. Henry). We compared three treatments (peat moss (control), peat moss mixed with vermiculite, and peat moss mixed with biochar) at three times (pre-experiment, pre-fertilizer, and post-fertilizer). The biochar and vermiculite mixes had significantly higher cation exchange capacity (CEC) and pre-experiment exchangeable K than the control....

Ozone (O3) and nitric acid (HNO3) are synthesized by the same atmospheric photochemical processes and are almost always co-pollutants. Effects of O3 on plants have been well-elucidated, yet less is known about the effects of HNO3 on plants. We investigated the physiological effects of experimental O3 and HNO3 fumigation on Phaseolus vulgaris (snap bean) and Nicotiana tobaccum (tobacco) varieties with known sensitivity to O3, but unknown responses to HNO3. Responses were measured as leaf absorptance, aboveground plant biomass, and photosynthetic CO2-response curve parameters. Our results...