HOW LOSS VERSUS INVASION OF A SPECIES ALTERS CONNECTED LAND-WATER ECOSYSTEMS

• Sponsoring Institution: National Institute of Food and Agriculture
• Project Status: COMPLETE
• Funding Source: HATCH
• Reporting Frequency: Annual
• Accession No.: 1022147
• Project Start Date: Mar 5, 2020
• Project End Date: Sep 30, 2022
• Program Code: [(N/A)]- (N/A)

Recipient Organization
UNIVERSITY OF MAINE
(N/A)
ORONO,ME 04469

Performing Department
School of Biology & Ecology

Non Technical Summary
Ecosystems are often thought of as compartmentalized units, such as a lake or forest. However, there are multiple materials and organisms that connect disparate ecosystems, creating food webs that cross landscapes(Polis et al. 1997). For example, a beetle falling from a tree into a stream becomes food for fish or seaweed washing up on a beach and provides food and habitat for terrestrial insects. Like most natural systems, humans are influencing these important landscape-scale food-web connections through avenues such as resource harvest or invasion/loss of species that cross ecosystem boundaries(Richardson and Sato 2015). Understanding consequences for altering cross-ecosystem connections is not only important to the ecological functioning of the involved ecosystems, but also to the natural resources that humans rely on.Maine's natural resource economy is highly tied to coastal and inland resource harvest.On the coast, resource harvest of seaweeds, such as the rockweedAscophyllum nodosum, is expandingto meet new economic demands. Rockweed harvest has occurred along the coast of Maine for decades(Rockweed Plan Development Team et al. 2014)doubling over the last ten years, with landings in 2018 for rockweed valued at $820,846 (Department of Marine Resources Landings data). Landed rockweed is processed into animal feed supplements, fertilizers, and soil amendments. Taking into account value-added products, Maine's seaweed industry has an estimated value of $20 million per year(Thayer and Schmitt 2013). In 2014, the Maine Department of Marine Resources (DMR) created a Fishery Management Plan (FMP) for Rockweed, identifying key needs for the future direction of rockweed research, including understanding how removal of rockweed through harvest alters intertidal food webs and adjacent terrestrial ecosystems through seaweed wrack(Rockweed Plan Development Team et al. 2014).Moving inland, one of Maine's most notable natural resources is forest harvest. Nested within Maine's forests are freshwater ecosystems, such as streams and lakes, that are highly connected to the forests through pathways such as leaves falling into streams or freshwater insects emerging and becoming food for spiders and birds(Baxter et al. 2005). To conserve the freshwater ecosystems and the forest/water connections, harvesters leave riparian buffers surrounding the freshwater ecosystems. However they come at a cost to the forest industry, with an estimated $3500-$7500 per hectare left behind in the buffers(LeDoux and Wilkerson 2006). During a 2017 listening session held by the Maine Cooperative Forestry Research Unit,Maine forest industry representatives identified the lack of information and consensus on the long-term effectiveness of alternative riparian buffers in the Maine as a critical research need. Forest practitioners expressed broad concern that buffers may be either be overly conservative and costly to forest production, or be ineffective in safeguarding freshwaters. Therefore, the forest industry and conservation managers both need research addressing the effects of different riparian buffers on the function of connected forest/freshwater ecosystems.Further complicating Maine's natural resource harvests is the addition/loss of species that alter cross-ecosystem interactions. For example, in Maine the invasive emerald ash borer has the potential to both decrease and increase cross-ecosystem connections(Gandhi and Herms 2010, Nisbet et al. 2015). It is not only removing ash trees from Maine's forest, therefore reducing leaf input to freshwaters, but also potentially increasing the input of the insect itself, which at high densities could increase drowning terrestrial insect food for fish.Therefore, my research will focus on understanding how the loss/addition of species through coastal and inland resource harvest and invasion/extirpations alters food webs that are connected across landscapes.Multiple industry and conservation stakeholders have expressed a need and will directly benefit from this research. I will be partnering with the rockweed and forest harvest industries, as well as the Department of Marine Resources, Maine Department of Inland Fisheries and Wildlife, US Fish and Wildlife Service, and Maine Forest Service to conduct the research and disseminate the findings.Baxter, C. V., K. D. Fausch, and W. C. Saunders. 2005. Tangled webs: reciprocal flows of invertebrate prey link streams and riparian zones. Freshwater Biology 50:201-220.Gandhi, K. J. K., and D. A. Herms. 2010. Direct and indirect effects of alien insect herbivores on ecological processes and interactions in forests of eastern North America. Biological Invasions 12:389-405.LeDoux, C. B., and E. Wilkerson. 2006. A case study assessing opportunity costs and ecological benefits of streamside management zones and logging systems for eastern hardwood forests. Res. Pap. NRS-1. Newtown Square, PA: U.S. Department of Agriculture, Forest Service, Northern Research Station. 16 p. 1.Nakano, S., H. Miyasaka, and N. Kuhara. 1999. Terrestrial-aquatic linkages: riparian arthropod inputs alter trophic cascades in a stream food web. Ecology 80:2435-2441.Nakano, S., and M. Murakami. 2001. Reciprocal subsidies: dynamic interdependence between terrestrial and aquatic food webs. Proceedings of the National Academy of Sciences of the United States of America 98:166-170.Nisbet, D., D. Kreutzweiser, P. Sibley, and T. Scarr. 2015. Ecological risks posed by emerald ash borer to riparian forest habitats: A review and problem formulation with management implications. Forest Ecology and Management 358:165-173.Piovia-Scott, J., D. A. Spiller, and T. W. Schoener. 2011. Effects of experimental seaweed deposition on lizard and ant predation in an island food web. Science 331:461-463.Polis, G. A., W. B. Anderson, and R. D. Holt. 1997. Toward an integration of landscape and food web ecology: the dynamics of spatially subsidized food webs. Annual Review of Ecology and Systematics 28:289-316.Polis, G. A., and S. D. Hurd. 1996. Allochthonous input across habitats, subsidized consumers, and apparent trophic cascades: examples from the ocean-land interface. Pages 275-285inG. A. Polis and K. O. Winemiller, editors. Food Webs. Springer US.Richardson, J. S., and T. Sato. 2015. Resource subsidy flows across freshwater-terrestrial boundaries and influence on processes linking adjacent ecosystems. Ecohydrology 8:406-415.Richardson, J. S., Y. X. Zhang, and L. B. Marczak. 2010. Resource subsidies across the land-freshwater interface and responses in recipient communities. River Research and Applications 26:55-66.Rockweed Plan Development Team, C. Bartlett, S. Redmond, C. J. Arbuckle, B. Beal, S. Brawley, S. Domizi, L. Mercer, D. Preston, G. Seaver, N. Sferra, P. Thayer, and R. Ugarte. 2014. Fishery Management Plan for Rockweed (Ascophyllum nodosumI). Maine Department of Marine Resources, Augusta, Maine, USA.Sabo, J. L., and M. E. Power. 2002. Numerical response of lizards to aquatic insects and short-term consequences for terrestrial prey. Ecology 83:3023-3036.Spiller, D. A., J. Piovia-Scott, A. N. Wright, L. H. Yang, G. Takimoto, T. W. Schoener, and T. Iwata. 2010. Marine subsidies have multiple effects on coastal food webs. Ecology 91:1424-1434.Thayer, P., and C. Schmitt. 2013. Rockweed: Ecology, Industry and Management. University of Maine Cooperative Extension and Maine Sea Grant in partnership with the Maine Department of marine Resources, Orono, Maine.Wallace, J. B., S. L. Eggert, J. L. Meyer, and J. R. Webster. 1999. Effects of resource limitation on a detrital-based ecosystem. Ecological Monographs 69:409-442.

Animal Health Component

60%

Research Effort Categories

Basic

40%

Applied

60%

Developmental

(N/A)

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
112	0320	1070	15%
123	0613	1070	15%
135	0899	1070	35%
136	3199	1070	35%

Knowledge Area
135 - Aquatic and Terrestrial Wildlife; 136 - Conservation of Biological Diversity; 112 - Watershed Protection and Management; 123 - Management and Sustainability of Forest Resources;

Subject Of Investigation
0320 - Watersheds; 3199 - Invertebrates, general/other; 0899 - Wildlife and natural fisheries, general/other; 0613 - Mixed conifer-broadleaf forests;

Field Of Science
1070 - Ecology;

Keywords

food web

ecosystem subsidy

landscape ecology

forested freshwaters

marine intertidal

rockweed

seaweed

species invasion

species loss

Goals / Objectives
Goal: Investigate how addition (invasion) versus removal (extirpation or harvest) of a species alters the stability and function of connected land-water ecosystems that support Maine's natural resources.Objectives:Measure how harvest of the rockweed impacts intertidal food webs, as well as the transfer of seaweed (wrack) to upland beach ecosystems. The results will help determine the sustainability of harvest along the coast of Maine.Survey impacts of differing riparian buffers from forest harvest to understand connected forest-stream food webs. This will help to increase sustainability of riparian buffer best management practices for forest harvest companies in western Maine.Experimentally test how additions (invasions) and losses (extirpations or harvest) of different species affect connected land-water ecosystems. Understanding the landscape scale consequences of species additions and losses will help support Maine's natural resources, such as resource harvest, fisheries, and tourism.

Project Methods
I will combine large, landscape-scale surveys with smaller mechanistic experiments to understand how adding versus losing species from Maine's ecosystems affects cross-ecosystem food webs and the sustainability of Maine's natural resources. My research will involve stakeholders that will directly use the findings to better connect science to conservation and industry.Objective 1: Working with the four major rockweed harvesters from the New Hampshire to Canadian border, I will conduct a large scale rockweed harvest before/after control/impact (BACI) harvest experiment. Multiple parts of the intertidal food web will be measured, including rockweed structure and biomass, abiotic factors (temperature, light), invertebrate communities, marine and shore birds. Measurement of intertidal invertebrate biomass (an important metric for ecological response to harvesting) is dependent on the availability of a microbalance for weighing individual invertebrates. The transfer of rockweed as a subsidy to the upland ecosystem will be measured as wrack biomass at varying intervals since harvest. Small scale experiments looking at rockweed as a subsidy to mudflat, saltmarsh, and upland ecosystems will also take place to determine what organisms use the rockweed subsidy and how fast it decomposes in the various ecosystems. There will be a Rockweed 2020 symposium, coordinated with Maine Sea Grant, to disseminate findings to all stakeholders, including industry, state and federal agencies, conservation groups, coastal landowners, and the general public.Objective 2: Forest harvest companies still have unanswered questions about the effectiveness of their best management strategies regarding riparian buffers and how effective they are at conserving forested freshwaters. In the early 2000's, a large-scale riparian harvest experiment was conducted in western Maine by Monomet Inc. and the Maine Cooperative Forestry Research Unit (CFRU). This manipulation provides a unique opportunity to measure the long-term (~15 year) impacts of different riparian harvest strategies on forest-freshwater connections. Surveys of the forest buffer ecosystem, including stand density, diversity, and estimated cost of remaining timber, combined with surveys of the stream ecosystem, including leaf breakdown rates, freshwater invertebrate communities, and fish density and biomass, will take place to characterize the forest and freshwater food webs. I will also look at the flux of subsidies between the forest and streams ecosystems by measuring leaf fall, insect emergence from streams, and ratio of terrestrial to aquatic taxa in the riparian zone. The surveys will be combined with a meta-analysis/analytical review of the ecological and economic outcomes of riparian buffer strategies in the North Eastern US. To incorporate undergraduate education into this objective, my EES senior capstone class (16 students) will be working on the meta-analysis, giving them an experience working on science that will directly be used by stakeholders. The results will be directly reported to the CFRU and multiple fact sheets on our findings (survey's and meta-analysis) will be presented to the forest harvest industry in Maine.Objective 3: There are many species in Maine that either add or remove subsidies (e.g. invasion and extirpation of fish, emerald ash borer, loss/invasion of trees) from food webs and therefore altering cross-ecosystem interactions. To test the effects these additions versus losses have on food webs and cross-ecosystem subsidies, I will conduct a suite of mesocosm (large cattle-trough) experiments. The addition of an species of concern will be crossed with the loss of the same species to aquatic food webs to determine which has a greater effect on the function and stability of the cross-ecosystem, land-water food webs. Changes in predator (fish), primary consumer (invertebrate), and primary producer (algae) will be used to calculate multiple measures of stability. Stable isotopes will also be used to help quantify feeding relationships critical to food-web response. Both invertebrate biomass and isotope analysis require a microbalance. By working with conservation groups and state/federal agencies, I will work with species of concern to Maine. This will allow for the advancement of important scientific knowledge in the field of ecology, as well as outputs that are important to stakeholders and their management of Maine's natural resources.

Progress 03/05/20 to 09/30/20

Outputs
Target Audience: Objective 1: For understanding the effects of Rockweed harvest along the coast of Maine, I am working with a multitude of collaborators and stake-holders. Their involvement spans conceptualization of design, feedback on methods, carrying out of experimental harvest, and dissemination of results. I am working with Brian Olsen (UMaine), Jessica Muhlin (Maine Maritime Academy), and Hannah Webber (Schoodic Institute) are my main academic collaborators on the project. We also have the following 21 stakeholder groups: Acadia National Park (government/conservation), Maine Coastal Island National Wildlife Refuge (government/conservation), Maine Department of Marine Resources (government/regulating agency), Maine Department of Inland Fisheries and Wildlife (government/regulating agency), US Fish and Wildlife Service (government/regulating agency), Phycoliffe LLC (industry/harvester), North American Kelp (industry/harvester), Acadian Seaplants (industry/harvester), Ocean Organics (industry/harvester), Source Inc. (industry/harvester), Maine Sea Grant (government/moderating agency), Island Institute (NGO/conservation), Maine Natural History Observatory (NGO/conservation), the Nature Conservancy (NGO/conservation), Maine Audubon (NGO/conservation), Schoodic Institute (NGO/conservation), Frenchman Bay Partners (NGO/Land Trust), Maine Coast Heritage Trust (NGO/land trust), Gulf of Maine Council on the Marine Environment (government/conservation), Maine Seaweed Council (NGO/land trust), and over 100 coastal Maine landowners. Over this reporting period, there were multiple presentations to both scientific and public audiences as well as disseminating a research updates newsletter to all stakeholders, including the ~100 coastal landowners. Objective 2: I will be working in a transdisciplinary team of multiple academic partners across units and universities, including: Hamish Greig (University of Maine Orono (UMO)-School of Biology and Ecology (SBE)), Shawn Fraver (UMO-School of Forest Resources (SFR)), Mindy Crandall (Oregon State University-College of Forestry), Steve Coghlan (UMO-Wildlife, Fisheries, and Conservation Biology (WFCB)), Robert Northington (Husson University), and Neil Thompson (UMaine Fort Kent). In addition, we are working with multiple forest harvest companies via the Cooperative Forestry Research Unit (CFRU), the CFRU itself, and Manomet Maine Inc. For objective two, there was a presentation that was open to the public and attended by mutiple people in the forest harvest industry and conservation organizations (both government and NGO). Objective 3: For the test of addition/loss of species that fall under each of projects in Objective 1 and 2, the above listed collaborators will still be involved. I will also be working with the Northeast Vernal Pool Working Group coordinated by Cyndy Loftin (UMO-WFCB), which includes multiple universities, state and federal agencies, and NGO/conservation groups. For objective 3, there was an internationalscientific journal publication that resulted in the disseminaton of research to the scientific audience. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Measure how harvest of the rockweed impacts intertidal food webs, as well as the transfer of seaweed (wrack) to upland beach ecosystems. The results will help determine the sustainability of harvest along the coast of Maine:Trained 5 graduate students (of which 1 MS student graduated), 2 undergraduate honors/independent study students/ and ~10 undergraduate research assistants. Survey impacts of differing riparian buffers from forest harvest to understand connected forest-stream food webs. This will help to increase sustainability of riparian buffer best management practices for forest harvest companies in western Maine:Trained 1 PhD student, 1 MS student, and 3 undergraudate reserach assistants. Experimentally test how additions (invasions) and losses (extirpations or harvest) of different species affect connected land-water ecosystems. Understanding the landscape scale consequences of species additions and losses will help support Maine's natural resources, such as resource harvest, fisheries, and tourism:Trained and mentored 1 PhD student. How have the results been disseminated to communities of interest?Please see the outputs/products in that section for a full description. What do you plan to do during the next reporting period to accomplish the goals? Measure how harvest of the rockweed impacts intertidal food webs, as well as the transfer of seaweed (wrack) to upland beach ecosystems. The results will help determine the sustainability of harvest along the coast of Maine:Publish multiple papers arising from the data collected, hold 1-2 town halls for our stakeholders, disseminate results to regulating government organizations. Survey impacts of differing riparian buffers from forest harvest to understand connected forest-stream food webs. This will help to increase sustainability of riparian buffer best management practices for forest harvest companies in western Maine:Publish scientific papers from survey, publish paper on meta-analysis, write multiple white papers for forest harvest industry in Maine on the resutls. Experimentally test how additions (invasions) and losses (extirpations or harvest) of different species affect connected land-water ecosystems. Understanding the landscape scale consequences of species additions and losses will help support Maine's natural resources, such as resource harvest, fisheries, and tourism:Publish mutiple papers, finish mathematical predictive modeling, and start empirical experiments or surveys.

Impacts
What was accomplished under these goals? Impact: Maine is a state that relies heavily on its natural resource based economy, including harvests, fisheries, and tourism. Many of its natural resource harvests are in need of scientific research to better inform the conservation and management of the resources. In addition, better understanding what invasions and extirpations of species of concern does to ecosystem function can help management of Maine's ecosystems at a landscape scale. The forest harvest industry has best management practices for riparian buffers that are conservative for the sustainability of the freshwaters that lay within the forests. However, they need scientific research on the balance between what is sustainable for the forests and freshwaters and maximizing their economic benefit from that land. Rockweed (a rocky intertidal seaweed) is another natural resource harvest that very recently has had its management and sustainability come into light due to court cases with the Maine Supreme Court. Managing rockweed harvest to balance ecosystem sustainability with economic benefit is depending on current research to inform policy. The proposed research will investigate how the addition (invasion) and loss (extirpation or harvest) of species alters cross-ecosystem, food-web function and stability to better manage ecosystems at a landscape scale. Not only does this research inform government and NGO conservation groups, it also will help industry better manage its natural resources and guide the public as to whether they want to use their land for harvest. Multiple large-scale experiments that manipulate harvest at an economically feasible industry scale in forests and seaweed/intertidal ecosystems will be crossed with smaller experiments to understand the mechanisms behind the landscape scale findings to understand how the loss or addition of species alters food-web function and stability. This research will be directly disseminated to Maine's forest and seaweed industries, as well as state and federal regulating industries, through white papers, fact sheets, and public forums. Ideally, this will lead to management strategies that sustain our healthy natural resources while maintaining economic growth for Maine's natural resource industries. Goal: Investigate how addition (invasion) versus removal (extirpation or harvest) of a species alters the stability and function of connected land-water ecosystems that support Maine's natural resources. Objectives: Measure how harvest of the rockweed impacts intertidal food webs, as well as the transfer of seaweed (wrack) to upland beach ecosystems. The results will help determine the sustainability of harvest along the coast of Maine. Major activities completed/experiments conducted:(a) Survey of bird communities in harvest and no harvest plots of the rockweed eocsystem. (b) Survey of invertebrate communities in harvest and no harvest plots of the rockweed ecosystems. (c) Survey of rockweed biomass in harvest and no harvest plots of the rockweed ecosystem. (d) Survey of wrack biomass at a subset of harvest and no harvest plots of the rockweed ecosystem. (e) Experiment on addition of rockweed wrack to upland beach and tidal-marsh ecosystems. (f) Experiment of oxygen consumption over 24-hour period to estimate rockweed eocsystem metabolism. Data collected:data associated with above surveys and experiments, including: Bird community composisiton, fecal meta-genomics on shorebird diet, invertebrate community density, rockweed biomass, temperature, light, and wave exposure, rockweed wrack breakdown rate and colonization by invertebrate communities, dissoved oxygen, pH, and temperature associated with rockweed. Summary statistics and discussion of results:Occupancy models for bird communities in the rocky intertidal zone;diet composition of shorebirds in the rocky intertidal based on fecal meta-genomics; preliminary analysis of rockweed biomass in harvest versus no harvest sites; invertebrate diversity. Key outcomes or other accomplishments realized:Maine's government and NGO conservation agencies, seaweed industry, and coastal land ownersreceived information on how rockweed harvest affects intertidal food webs, as well as the cross-ecosystem subsidies to upland ecosystems which could be used to help assess impacts. This was through private and public presentations as well as scientific publications. Survey impacts of differing riparian buffers from forest harvest to understand connected forest-stream food webs. This will help to increase sustainability of riparian buffer best management practices for forest harvest companies in western Maine. Major activities completed/ experiments conducted:Survey of 15-year old riparian forest harvest experiment including the survey of: invertebrates, fish, cross-ecosystem subsidies, tree composistion and size. Data collected:Data associated with survey above including: invertebrate density and biomass, fish biomass, invertebrate emergence from streams, tree density, type, and size. In addition, starting to collected data for a meta-analysis on the effects of riparian managment strategies on stream ecosystems in the northeastern US and southeastern Canada. Summary statistics and discussion of results:ordination, linear models, and meta-analysis statisitics for above data collected. Key outcomes or other accomplishments realized:Maine's forest industry will learn the long-term impacts of forest harvest and different riparian buffers on stream and forest ecosystems which can inform future riparian buffer best management strategies. This included publication of a masters thesis at the UMaine library as well as a public presentation of the results. Working on a publication and white paper for industry summarizing results from the meta-analysis. Experimentally test how additions (invasions) and losses (extirpations or harvest) of different species affect connected land-water ecosystems. Understanding the landscape scale consequences of species additions and losses will help support Maine's natural resources, such as resource harvest, fisheries, and tourism. Major activities completed/ experiments conducted:Started assembling a mathematical model to test the addition/loss of a species on food-web stability. Data collected:No New data was collected from the above model yet. Summary statistics and discussion of results:Analyzed data from adding terrestrial invertebrate and leaf species to pond food-webs and how that alters subsidies back to the terrestrial ecosystem. In addition, analyzed the impacts of the addition of those terrestrial invertebrates and leaves to pond food-webs. Key outcomes or other accomplishments realized: Scientific community will be informed of consequences of adding/versus removing species. Paper published in interational scientific journal.

Publications

• Type: Journal Articles Status: Published Year Published: 2020 Citation: Klemmer, A.J., Galatowitsch, M., McIntosh, A.R. 2020. Cross-ecosystem bottelnecks alter reciprocal subsidies within meta-ecosystems. Proceedings of the Royal Society B. https://doi.org/10.1098/rspb.2020.0550
• Type: Conference Papers and Presentations Status: Other Year Published: 2020 Citation: Klemmer, A.J., Shepard, I., McIntosh, A.R. 2020. Subsidy trophic level differentially affects bottom-up and top-down food-web interactions. Presentation at the University of Canterbury, Freshwater Ecology Research Group presentation. Online due to COVID-19
• Type: Conference Papers and Presentations Status: Other Year Published: 2020 Citation: Klemmer, A.J., Olsen, B.J., Muhlin, J., Webber, H., Mittelstaed, H., Johnston, E. 2019. Connecting science with stakeholders: Rockweed food webs and commercial harvesting. Maine Sea Grant 2020 project awardees. Zoom
• Type: Conference Papers and Presentations Status: Published Year Published: 2020 Citation: Johnston, E., Klemmer, A.J., Foster, J.T., Mau, R.L., Mittelhauser, G.H., Olsen, B.J. 2020. Using fecal metabarcoding to reconstruct the winter diet of a declining shorebird species. North American Ornithological Conference. Online due to COVID-19
• Type: Other Status: Accepted Year Published: 2020 Citation: Funding obtained by leveraging this project: Klemmer, A.J., Olsen, B.J., Mittelstaedt, H. National Park Service  Cooperative Ecosystem Studies Unit. Environmental correlates of rocky intertidal community structure. $59,076
• Type: Other Status: Accepted Year Published: 2020 Citation: Funding obtained by leveraging this project: Greig, H.S., Klemmer, A.J. NOAA  Cooperative Institute for the North Atlantic Region. Stream invertebrate and ecosystem responses to Atlantic salmon freshwater habitat restoration. $170,289