Multiple models guide strategies for agricultural nutrient reductions

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/136504/1/fee1472_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136504/2/fee1472-sup-0008-WebTable7.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136504/3/fee1472-sup-0004-WebTable3.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136504/4/fee1472.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136504/5/fee1472-sup-0006-WebTable5.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136504/6/fee1472-sup-0002-WebTable1.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136504/7/fee1472-sup-0005-WebTable4.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136504/8/fee1472-sup-0007-WebTable6.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136504/9/fee1472-sup-0003-WebTable2.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136504/10/fee1472-sup-0001-WebFig1.pd

Using a Multi-Institutional Ensemble of Watershed Models to Assess Agricultural Conservation Effectiveness in a Future Climate

This study investigates the combined impacts of climate change and agricultural conservation on the magnitude and uncertainty of nutrient loadings in the Maumee River Watershed, the second-largest watershed of the Laurentian Great Lakes. Two scenarios — baseline agricultural management and increased agricultural conservation — were assessed using an ensemble of five Soil and Water Assessment Tools driven by six climate models. The increased conservation scenario included raising conservation adoption rates from a baseline of existing conservation practices to feasible rates in the near future based on farmer surveys. This increased adoption of winter cover crops on 6%–10% to 60% of cultivated cropland; subsurface placement of phosphorus fertilizers on 35%–60% to 68% of cultivated cropland; and buffer strips intercepting runoff from 29%–34% to 50% of cultivated cropland. Increased conservation resulted in statistically significant (p ≤ 0.05) reductions in annual loads of total phosphorus (41%), dissolved reactive phosphorus (18%), and total nitrogen (14%) under the highest emission climate scenario (RCP 8.5). While nutrient loads decreased with increased conservation relative to baseline management for all watershed models, different conclusions on the true effectiveness of conservation under climate change may be drawn if only one watershed model was used.publishedVersio

Invasive Dreissenid Mussel Effects on Phosphorus Dynamics in Lake Ontario: Insights from Integrated Hydrodynamic-Ecological Modeling

Invasive dreissenid mussels have a profound effect on the total phosphorus (TP) budget in Lake Ontario, which in turn influences ecological processes such as the resurgence of the benthic alga Cladophora. A validated three-dimensional integrated hydrodynamic and ecological modeling framework is applied to quantify the impact that dreissenids have on the spatial and species distribution of TP in the lake. Model results for April to September 2013 show that dreissenids decrease TP in the water column by about 1812 metric tons (MT), which is about 60% of the tributary TP loading to the lake. This reduction in TP affects other processes controlling its distribution. Physical transport of TP from nearshore to offshore waters is reduced, and the amount of TP involved in chemical reactions is reduced, while TP processed by biological transformations is increased. This study provides the first attempt to quantify the TP budget changes in Lake Ontario by dreissenids using numerical modeling, and findings of this study can be generalized to other lakes with similar conditions.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Multiple models guide strategies for agricultural nutrient reductions

For nearly twenty years in the western United States, billions of dollars have been spent to recover anadromous salmon species listed under the federal Endangered Species Act. Broad support and participation from the private and public sectors is needed to address the limiting factors to salmon viability, especially the improvement of stream and watershed health. However, in today’s fiscal and political climate it is more important than ever to demonstrate the multiple ways that conservation work benefits not just the environment but also our economy. This paper examines the employment and economic impacts of watershed restoration expenditures made in Oregon from 2001–2010, making use of multipliers developed by the University of Oregon’s Ecosystem Workforce Program. We collected data on salmon habitat restoration projects from a statewide database system, the Oregon Watershed Restoration Inventory, and grouped project activities according to the University of Oregon restoration employment and economic multiplier categories. To determine the total direct, indirect, and induced economic output and employment resulting from restoration investments, we multiplied the total project investment in each category of restoration work by the relevant multiplier. We then summed the total economic activity by project type to arrive at a total per county and the state. We found that a total of US$411.4 million was invested in 6,740 watershed restoration projects throughout the state of Oregon from 2001 to 2010, resulting in the generation of between$752.4 million and $977.5 million in economic output and 4,628 to 6,483 jobs. The jobs created by restoration activities are located mostly in rural areas, in communities hard hit by the economic downturn. Restoration activities bring a range of employment opportunities for people in construction, engineering, natural resource sciences, and other fields. The job creation potential of restoration activities compared with investments in other sectors of the economy is favorable. Restoration also stimulates demand for the products and services of local businesses such as plant nurseries, heavy equipment companies, and rock and gravel companies. Unlike in other economic sectors, restoration jobs can’t be outsourced to distant locations, so these dollars tend to stay in the local and state economy. Restoration investments also continue to accrue and pay out over time. Long-term improvements in habitat create enduring benefits, from enhanced recreational and fishing opportunities to the provision of critical ecosystem services. These findings are good news to the people of Oregon and there is tremendous opportunity to extend and replicate this work to other regions. Being able to effectively communicate the interdependencies of ecosystems and economies is critical to addressing the immense challenges of the 21st century. As long as we continue to frame trade-offs in simplistic terms like jobs versus the environment, we will be relegated to making incremental change. Whether our aim is the recovery of wild salmon in the Western United States or the abatement of greenhouse gas emissions; alternative models for economic development need to be redoubled. We have found that quantifying and presenting the economic benefits of watershed restoration reframes the conversation and opens doors to new alliances