Treesearch

Captive propagation has become an important tool in the conservation of imperiled freshwater mussels. Previous studies provide conflicting results about the effects of food abundance on survival and growth of juvenile mussels in aquaculture, and the extent to which growth in the hatchery reflects growth in the wild is unknown. We evaluated the effects of abundance of an algal-based diet on survival and growth of juvenile Cumberland Bean (Venustaconcha troostensis) in a recirculating aquaculture system. We compared food abundance (as fine particulate organic matter, FPOM) in our...

Characterization of physical fuel distributions across heterogeneous landscapes is needed to understand fire behavior, account for smoke emissions, and manage for ecosystem resilience. Remote sensing measurements at various scales inform fuel maps for improved fire and smoke models. Airborne lidar that directly senses variation in vegetation height and density has proven to be especially useful for landscape-scale fuel load and consumption mapping. Here we predicted field-observed fuel loads from airborne lidar and Landsat-derived fire history metrics with random forest (RF) modeling. RF...

There are more than 300 million hectares of forested land within the conterminous United States essential to sustaining the myriad social/cultural, economic, and ecologic benefits society enjoys from these lands. Nationwide, millions of forested hectares, both private and public, are disappearing functionally and physically through serve wildfire fire and land conversion. On many of these lands, management, centered on fire suppression, has led to reductions in forest resilience to wildfire. Lands, overstocked with accumulated fuel and faced with a changing climate, are expected to...

The taxonomy of annulate [possessing a ring-like structure on the stipe (stem) of the basidiocarp (mushroom, fruiting body, basidioma) that is the remnant of the ruptured veil on the underside of the cap] Armillaria (Figs. 20.1E-J, 20.2, and 20.3) and its exannulate (without an annulus) sister genus Desarmillaria (Fig. 20.1K) is constantly changing. However, at least 40 species are currently recognized around the world (Baumgartner et al., 2011; Koch et al., 2017; Heinzelmann et al., 2019; Antonín et al., 2021; Kedves et al., 2021), and most Armillaria spp. have a wide host range. In many...

Intactness is a commonly used measure of ecological integrity, especially when evaluating conservation status at the landscape scale. We argue that in the large and relatively unfragmented landscapes of the Arctic and sub-Arctic, intactness provides only partial insight for managers charged with maintaining ecological integrity. A recent landscape assessment suggests that 95% of Alaska shows no measured direct or indirect impacts of human development on the landscape. However, the current exceptionally high levels of intactness in Alaska, and throughout the Arctic and sub-Arctic, do not...

The removal of dams from rivers has become a common and widespread practice in the United States and Europe. Although often initiated by factors like economics and safety, ecosystem restoration is often a desired benefit and outcome of dam removal. We describe the physical and ecological effects that the placement and removal of dams have on rivers. We then focus on the drivers of dam removal, present considerations for undertaking a dam removal project, and discuss case-studies and recent syntheses describing the ecological outcomes of dam removal.

Laurel wilt is a destructive vascular disease of trees in the laurel family (Lauraceae) caused by a nonnative insect/pathogen complex. This study monitored the recent spread and impact of laurel wilt in sassafras (Sassafras albidum [Nutt.] Nees) from the Gulf-Atlantic Coastal Plain region of the southeastern United States (US) into the adjacent Piedmont/Sandhills and Mountain regions. Laurel wilt was detected at thirteen of forty-six sassafras sites including seven outside the Coastal Plain. Compared to nondiseased sites, sassafras mortality due to laurel wilt increased rapidly from 2018...

A predator, Laricobius osakensis Montgomery and Shiyake (Coleoptera: Derodontidae), is being mass-produced and released for the biological control of the invasive hemlock woolly adelgid (HWA), Adelges tsugae Annand (Hemiptera: Adelgidae). To better understand and predict the seasonality of this predator in North America, the development and reproduction of L. osakensis were evaluated at constant temperatures ranging from 5 to 22°C. The predicted seasonal biology was compared with data from field collections. L. osakensis did not complete development from egg to adult at the two lowest...

The southern pine beetle, Dendroctonus frontalis Zimmermann (Coleoptera: Curculionidae: Scolytinae), is a major pine tree killer in North and Central America. In the southeastern USA, responses by D. frontalis to its aggregation pheromone can be substantially increased by at least three host odours: the monoterpenes alpha-and beta-pinene, and the phenylpropanoid 4-allylanisole. We executed three trapping experiments to assess the influence of 4-allylanisole release rate on aggregation behaviour of D. frontalis and to evaluate the compound as an adjuvant for the operational monitoring lure...

Climate change is altering the geographic distribution of many species, including numerous forest insect pests, with the potential for severe impacts to forest ecosystems. The southern pine beetle (Dendroctonus frontalis), one of the world’s most persistently destructive forest pests, has extended its distribution towards the north, while impacts within its historic range in the southeastern United States have diminished, indicating that a range shift may be occurring. This pattern could be explained by the hypothesis of climatic envelopes if summers in the southern part of the range are...