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Penn State Soil Characterization Lab

Soil is an integral part of ecosystem function. There are 29 million acres (11,735,884 hectares) of soil in Pennsylvania supporting: wetlands; forest lands; agricultural lands; urban lands; homes, businesses, and roads; our drinking and wastewater filtration. Without soil, these activities and functions would be much more difficult and in some cases even impossible, for soil is as precious to our lives as the very blood in our bodies.

Research in the Soil Characterization Laboratory focuses on people’s use of landscapes and the accompanying changes in soil function across the larger ecosystem the soil supports. Dr. Drohan’s research group addresses basic science questions, but also demonstrates how this new knowledge can be applied to improve land management and ecosystem stability.

Soil Characterization Lab News

COVID-19 Idea for US States: State Agriculture Assessment Team Risk Planning
March 26, 2020
Our lab group knows of no current issues with the Agricultural supply chain in the USA and COVID-19 disruptions. However, the potential trend of "soon overwhelmed health systems" has us concerned. What we are most concerned about is a fragile demographic (farming now) and the risk of C19 further disrupting it and creating a negative economic feedback. Around the USA, Land Grants could take a lead in developing Agriculture Assessment Planning Teams but state committee membership should not be limited to College of Ag members. There are likely people in Business programs, other academic departments, and outside University entities, who all could be helpful to have on such a committee. For example, are their retired military experts in logistics planning who could be members? We are currently working with others to support development of a support network for farmers.
NEW PAPER: Soil Chemistry, and Not Short-term (1-2 year) Deer Exclusion, Explains Understory Plant Occupancy in Forests Affected by Acid Deposition
October 23, 2019
Danielle R Begley-Miller, Duane R Diefenbach, Marc E McDill, Patrick J Drohan, Christopher S Rosenberry, Emily H Just Domoto. In AoB PLANTS: The loss of species diversity and plant community structure throughout the temperate deciduous forests of North America have often been attributed to overbrowsing by white-tailed deer (Odocoileus virginanus). Slow species recovery following removal from browsing, or reduction in deer density, has been termed a legacy effect of past deer herbivory. However, vegetation legacy effects have also coincided with changes to soil chemistry throughout the north-eastern USA. In this paper, we assess the viability of soil chemistry (i.e. pH, extractable nutrients and extractable metals) and other factors (topography, light, overstory basal area and location) as alternative explanations for a lack of vegetation recovery. We compared the relative effects of soil chemistry, site conditions and short-term (1–2 year) deer exclusion on single-species occupancy probabilities of 10 plant taxa common to oak-hickory forests in central Pennsylvania. We found detection for all modelled species was constant and high (⁠p^ > 0.65), and occupancy probability of most taxa was best explained by at least one soil chemistry parameter. Specifically, ericaceous competing vegetation was more likely to occupy acidic (pH < 3.5), base cation-poor (K < 0.20 cmolc kg−1) sites, while deer-preferred plants were less likely to occur when soil manganese exceeded 0.1 cmolc kg−1. Short-term deer exclusion did not explain occupancy of any plant taxon, and site conditions were of nominal importance. This study demonstrates the importance of soil chemistry in shaping plant community composition in the north-central Appalachians, and suggests soil as an alternative, or additional, explanation for deer vegetation legacy effects. We suggest that the reliance on phyto-indicators of deer browsing effects may overestimate the effects of browsing if those species are also limited by unfavourable soil conditions. Future research should consider study designs that address the complexity of deer forest interactions, especially in areas with complex site-vegetation histories.
Lab Fulbright Scholar Jhony Benevides presents thesis work at Colombian Fulbright event
August 27, 2019
MS student Jhony Benevides was one of 4 Penn State Fulbright Scholars affiliated with the Cacao for Peace program to present at a Colombian Fulbright sponsored Cátedra in Monteria, Colombia.