Terrestrial Liming As a Restoration Technique for Acidified Forest Ecosystems

We studied the effects of liming on soils and forest songbirds as well as vegetation and calcium-rich invertebrate prey variables that were predicted to link birds to changes in soil conditions. We observed increases in soil pH, calcium, and magnesium, as well as in songbird abundances in response to lime application, with continuing increases through five years after liming. We observed an overall increase in snail abundance on limed sites, but an initial peak of a 23 fold increase three years after liming was reduced to an 11 fold increase five years after liming. We observed an increase in forb ground cover on limed sites, but liming had no effect on millipede abundance or other vegetation measures. Of the variables we measured, snail abundance was the most likely mechanism for the response in bird abundances. Because we observed continued benefits of liming up to five years post treatment, we concluded that liming is a very promising technique for restoring forest ecosystems impacted by acidic deposition

The astrobiology primer: An outline of general knowledge - Version 1, 2006

Peer reviewe

Assessment of Road Culverts as Passage Barriers to Wild and Stocked Trout in Pennsylvania Headwaters

One of the primary threats to brook trout in Pennsylvania is population fragmentation due to habitat alteration. Road culverts in particular can isolate populations by reducing access to upstream spawning habitat. To categorize the degree to which culverts prevent fish movement, watershed managers use physical measurements to classify the passability of the each culvert. The North Atlantic Aquatic Connectivity Collaborative (NAACC) conservatively categorizes culverts as “no AOP (Aquatic Organism Passage)” or “red culverts” when they are considered a barrier to aquatic organisms. The Little Bear Creek watershed, a wild trout stream in the Loyalsock watershed, contains three culverts categorized as “reduced AOP” or “gray culverts” that require further investigation to determine actual organism passage. It is unknown whether these gray culverts are indeed barriers to migratory fish, especially native trout. To measure how passable these culverts are, we tagged 546 wild trout in 2015 and 2016 with passive integrated transponder (PIT) tags, distributed up and downstream of each culvert site and a control site without a culvert. Results show that trout are differences in movements between culvert types, implicating a barrier issue in Little Bear’s tributaries. The only metal corrugated culvert in the watershed, which lies on the upper most extent of Sand Spring Run, has proven to be the most passable of the culverts with an average of 0.85 movements per day. A small box culvert on the lower extent of Sand Spring Run had an average of 0.1 movements per day. The largest culvert, a more recently built box culvert close to the mouth of Red Run, had an average of 0.01 movements per day. None of the movements in Red Run were upstream movements. The barrier-free site on Painter Run resulted in an average of 0.27 movements per day. We will further test for correlations of trout movements with daily stream conditions such as temperature and water level. By “ground-truthing” culvert assessment methods, we anticipate our study will ultimately help watershed managers better prioritize culverts for removal or replacement

Assessment of Road Culverts as Passage Barriers to Brook Trout (Salvelinus fontinalis) and Brown Trout (Salmo trutta) in Pennsylvania Headwaters

Road culverts can pose as barriers to migratory fish and other aquatic organisms, which can lead to small isolated populations. To categorize the degree to which culverts prevent fish movement, watershed managers use physical measurements to classify culverts as “green” if they are passable, “red” if they are impassable, or “gray” if passability cannot be determined. The Little Bear Creek watershed, a small subwatershed within Loyalsock Creek, contains several road culverts that fell within the “gray” category. It is unknown to us whether or not the culverts falling within this category are indeed barriers to migratory fish, especially trout. To measure how passable these culverts are, we tagged 486 brook trout (Salvelinus fontinalis) and brown trout (Salmo trutta) with passive integrated transponder (PIT) tags throughout the Little Bear watershed, particularly upstream and downstream of the three “gray” culverts. Antenna arrays were constructed on the upstream side and downstream side of each culvert, as well as a control site lacking anthropogenic barriers to trout movement. In addition to tracking whether or not the culverts are passable, the arrays will reveal the exact time of movements through culverts. This will allow us to test for correlations with stream flow, water temperature, and other stream conditions that may influence trout movements. By “ground-truthing” culvert assessment methods, we anticipate our study will ultimately help watershed managers better prioritize culverts for removal or replacement

Assessment of Brook Trout Passage Through Ambiguous Culvert Barriers in Pennsylvania Headwater Streams

Habitat fragmentation driven by human activity is a common threat to aquatic organisms. Road culverts in particular can isolate fish populations and reduce genetic diversity by preventing access to upstream spawning habitat. The prioritization process for removing culverts and restoring connectivity includes an assessment of passibility. Culverts often receive scores that categorize them as partial barriers, known as “Reduced AOP” culverts, however detailed assessment of passibility on gray culverts is lacking. To fill this research gap, we used stationary PIT-tag readers to investigate brook trout passage through two No AOP culverts, one Reduced AOP culvert, and a reference stream lacking a culvert for 16 months in Little Bear Creek of Lycoming Co., PA. Results indicate significant differences in upstream movement rates among culvert sites. The rate of upstream passage was five times greater through the metal corrugated culvert than the reference stream. In contrast, relatively little upstream movement occurred through the two box culverts (up to 13 times less passage than the reference), indicating drastic passage differences in culverts receiving similar passibility scores. Our study implies that more nuanced culvert classifications may be needed to accurately reflect fish passage

Microbial communities associated with passive acidic abandoned coal mine remediation

Acid mine drainage (AMD) is an environmental issue that can be characterized by either acidic or circumneutral pH and high dissolved metal content in contaminated waters. It is estimated to affect roughly 3000 miles of waterways within the state of Pennsylvania, with half being acidic and half being circumneutral. To negate the harmful effects of AMD, ∼300 passive remediation systems have been constructed within the state of Pennsylvania. In this study, we evaluated the microbial community structure and functional capability associated with Middle Branch passive remediation system in central PA. Sediment and water samples were collected from each area within the passive remediation system and its receiving stream. Environmental parameters associated with the remediation system were found to explain a significant amount of variation in microbial community structure. This study revealed shifts in microbial community structure from acidophilic bacteria in raw AMD discharge to a more metabolically diverse set of taxa (i.e., Acidimicrobiales, Rhizobiales, Chthoniobacteraceae) toward the end of the system. Vertical flow ponds and the aerobic wetland showed strong metabolic capability for sulfur redox environments. These findings are integral to the understanding of designing effective passive remediation systems because it provides insight as to how certain bacteria [sulfate reducing bacteria (SRBs) and sulfur oxidizing bacteria (SOBs)] are potentially contributing to a microbially mediated AMD remediation process. This study further supports previous investigations that demonstrated the effectiveness of SRBs in the process of removing sulfate and heavy metals from contaminated water