Altering disturbance regimes for monarch butterfly conservation

Nathan Haan, Michigan State University & Douglas Landis, Michigan State University

Many species of conservation concern depend on disturbance to create or maintain suitable habitat. We tested effects of disturbance on the eastern migratory monarch butterfly (Danaus plexippus L.), which has declined markedly in recent decades, primarily attributed to the loss of milkweed host plants from annual crop fields in the US Midwest. Currently, remaining milkweeds in this region primarily occur in perennial grasslands, where disturbance is infrequent, predatory arthropods are abundant, and seasonal patterns of plant phenology differ from crop fields. In a two-year study in Michigan, we applied three treatments to 23 patches of common milkweed (Asclepias syriaca L.); one-third of each patch was left undisturbed, while the remaining thirds were mowed in either mid-June or mid-July and allowed to regenerate. We subsequently measured effects on monarch oviposition, predator abundance, survival of sentinel eggs and larvae, and tested how milkweed phenology and aphid colonization—both of which are reset by disturbance—structure predation risk for immature monarchs. Monarchs laid significantly more eggs on regenerating versus undisturbed stems under both mowing regimes. Predators were strongly suppressed by mowing treatments, requiring 3-5 weeks to recolonize milkweed after disturbance, and were more abundant on flowering or aphid- infested stems. We found no significant differences in monarch egg/larval survival, although it tended to be higher in mowed plots. Overall, our results suggest that monarchs prefer regenerating stems for oviposition where their offspring may experience enemy-free space. Future work should focus on testing grassland disturbance as a management tool to improve productivity of existing monarch breeding habitat.

An ecological trait database of North American freshwater invertebrates for the assessment of climate change effects on streams

Ethan Hiltner, Michigan State University

Climate change is a threat to freshwater invertebrates around the world primarily due to the specific climatic and environmental conditions many of these species require. Because these freshwater invertebrates are so important to the overall health of an ecosystem, we have set out to create a database that includes their functional traits, for use in future ecological studies. Functional traits are ecologically based traits commonly used to understand relationships between organisms and their environment, including organismal distribution, and species diversity. However, without the compilation of such traits, it is difficult to quantify relationships between the environment and functional diversity for use in large-scale studies. Consequently, we are expanding the USEPA biological trait database, which includes traits of invertebrates in the United States, to include traits for more species in more locations. Functional traits included in this database pertain to life-history, habitat preference, dispersal ability, and morphology. Data contributions were obtained by using standardized search protocols to search books, online trait repositories, and the primary literature in Web of Science and Google Scholar. The final product will be a functional trait database for over 1,200 freshwater invertebrate genera that occur across North America. Other researchers will be able to access our database for future studies on the composition of functional traits, and the relationships between functional traits and the environment across North America. In future studies, we will use this database in conjunction with species occurrence records to investigate influences of climate, elevation, primary productivity, and land-use on freshwater invertebrate communities.

Bringing Biodiversity to Restored Grasslands

Carol Day, Cornerstone University & Dana Van Huis, Aquinas College

The research conducted looked at four prairies on the property of Pierce Cedar Creek Institute to understand what prairie management technique produces the most biodiversity. The management techniques used were prescribed burning and rotational mowing. Invertebrate, plant and bird surveys were taken in each prairie throughout the growing season to measure the biodiversity. The prairie that received prescribed burning showed the most biodiversity overall. This is the first year of this research study.

Community level response to deer herbivory and trampling in spring flora

Kyle Lough, University of Michigan

White-tailed deer (Odocoileus virginianus) are an abundant herbivore in the northern United States with a high capacity to devastate plant communities. There is strong evidence that herbivory (i.e. loss of plant biomass due to attempted or completed consumption by deer) and trampling are the primary mechanisms that are responsible for the negative impact of deer on vegetation (Côté et al. 2004). In this experiment, I used five metrics to assess the impacts that deer have on plant communities in city parks in Ann Arbor, Michigan: observable damage, vegetation density, change in density over time, Floristic Quality Index (FQI), and proportion of plants with reproductive characters. Using these metrics, I compared plant communities in pairs of fenced (with no deer access) and unfenced plots (with deer access) to determine if deer have a significant negative impact on the focal plant communities. My results provide strong evidence that deer are exerting a significant negative impact on the focal plant communities via the mechanisms of herbivory and trampling.

Deep Map of ACRES Land Trust

Brett Bloom, Oak Farm Montessori School

Deep Map of ACRES Land Trust, an organization protecting over 7000 acres of land. We (Brett Bloom and Bonnie Fortune) spent a year and a half conducting interviews and visiting ACRES sites. We wanted to visualize the social ecology and complexity that ACRES unleashes with the simple decision to protect land. In a time of intense political polarization, ACRES offers a way to protect the environment that is inclusive of people of diverse backgrounds and ideologies.

Engaging the Community In Stewardship of Urban Natural Areas

Michael Benham, The Stewardship Network, Jonathan Parker, Ann Arbor Natural Area Preservation & Mark Charles, Ann Arbor Natural Area Preservation

Preservation & Mark Charles, Ann Arbor Natural Area Preservation
Stewardship of natural areas requires substantial efforts – solo and collaborative, mental and physical.  Most important, these efforts must be sustained for years and decades. Three volunteers recount how collaborative efforts have helped them be effective for several years of ecologically-significant progress. Neighbors, grade-school classes, scouts, college students, and other community groups have been essential partners.

Exploratory Inventory of Invasive Plant Species on the Shiawassee River

Nathaniel Fike, North Oakland Headwaters Land Conservancy/Central Michigan University

Exotic and invasive plant species threaten native plant and animal populations through habitat alteration and resource consumption. High density populations of non-native vegetation crowd out biodiversity and alter host ecosystems, impacting both natural ecology and recreation potential. GPS, ArcGIS and the MISIN app were used to map non-native plant species on the Shiawassee River from Holly to Byron, Michigan. The project indexed and mapped over 10 invasive species but found no indication of emerging species from the current DNR watch list. This exploratory inventory has already lead to the initial removal of patches of flowering rush and purple loosestrife from the river. Further inventory efforts and management decisions could benefit from this assessment and continually build upon such knowledge of the Shiawassee River, a currently proposed National Water Trail.

First year wildflower establishment is influenced by pre- and post-seeding ground management strategies and seeding rate

Logan Rowe, Michigan State University

The incorporation of wildflower habitat into land management programs is a direct measure that land managers can take to support local populations of pollinators. Despite great interest in pollinator conservation through habitat restoration, managers face a number of challenges when installing wildflower habitat, such as wildflower species selection and pre- and post-seeding ground management strategies to best support the establishment of target species. In 2017, we began an experiment to determine how seeding rate (high vs low) influences the variability in plant establishment outcomes in relation to ground preparation strategies prior to seeding (mowing, herbicide, cover crop), and long-term management strategies post seeding (mowing, mowing plus herbicide, no intervention). Here, we report on the results following the first year of wildflower establishment in these plots, and demonstrate that both seeding rate and ground management influence wildflower establishment during the first year after broadcast seeding. Future work will assess how variability in management approaches influences the associated community of beneficial insects visiting plantings. Our results will inform land managers in our region on the best habitat management strategies to promote successful wildflower planting establishment and which strategies provide the most support to pollinators and other beneficial insects.

Forest Ecological Classification of Shiawassee National Wildlife Refuge

Douglas Putt, Wayne State University

Successful restoration efforts depend heavily on well-defined restoration goals based on a sound understanding of select reference ecosystems. Several projects at Shiawassee National Wildlife Refuge (SNWR) include reforestation with the objective of mimicking the natural vegetation present prior to extensive modification by agriculture and recreation. Approximately 50% of SNWR is forested yet the forested areas remain some of the most poorly understood ecosystems within the refuge. A forest ecological classification that investigates the physiography and soil characteristics of these forested areas as well as vegetation will not only fill the knowledge gaps about the existing forest ecosystems but will also serve a dual purpose of providing sound restoration goals using the existing forested areas as reference ecosystems. Our current ecological surveys have identified and described 12 unique forest ecosystems within SNWR that will provide an important framework for understanding ecological relationships across the landscape moving forward.

Master Plan Development for a Five-acre Pollinator Habitat on the Emergency Secondary Spillway for the Lake Ovid Dam at Sleepy Hollow State Park

Adelyn Geissel, Michigan State University

Native pollinator populations have been in decline in relatively recent years. The use of pesticides, genetically modified crops, and mono-culture-based agriculture has resulted in a loss of native habitat for pollinators as land use has changed from natural ecosystems to large swaths of agricultural fields. Pesticides have contributed to the demise of pollinator colonies as the result of sub-lethal, but behavior-disrupting pesticides. While it is difficult to track native pollinator population levels, the decline of pollinator populations definitely has been observed in iconic pollinator species. Through an increase in public awareness due to the decrease in monarch butterfly and European honey bee populations, programs to arrest the population decline and to return native pollinator populations to healthy, resilient numbers have been implemented in many regions.

The State of Michigan has developed a pollinator protection plan in response to the 2014 Presidential Memorandum and has created a task force with the goal of increasing pollinator populations. In response to this protection plan, and with the help of enthusiastic community partners, Sleepy Hollow State Park (SHSP), a large, 2600-acre park located thirty minutes north of Okemos, Michigan, is actively identifying sites within the park where large-scale pollinator habitats can be developed. SHSP staff, working with a community partner, have determined that the first site to be developed will be the Lake Ovid Dam Emergency Secondary Spillway area, a five-acre plot on the north side of the lake. As continual community input into and participation in the development of the proposed pollinator habitat will be necessary to increase the long-term support for this and other pollinator habitats within the park, community engagement will be key to the success of this project.

This project is currently in the initial planning stages. Plant species found in and around the proposed plot have been recorded and cataloged, soil samples have been taken, and initial discussions have been completed. The final product of this project will be a Master Plan that will detail: relevant descriptive and historical information about the site, rationale for the proposed habitat transition, an inventory of existing plant species, strategies to engage community stakeholders, recommended timeline for site development, and a catalog of potential sources for pollinator garden seed and funding.

Understanding Water Use and Dynamics of of Cropping Systems in Southwest Michigan Using Remote Sensing

Prakash K. Jha, Michigan State University

Better understanding of the drivers to the dynamics of complex agroecosystem is crucial to achieve the goal of a sustainable food system. Crop identification, delineation of crop areas and time series analysis is one way of understanding cropping system dynamics. Remote sensing plays a significant role in identifying and delineating the trend. Southwest Michigan has diverse and evolving cropping systems, which alters water-energy interactions in the landscape due to changes in landscape’s roughness, resulting to variable crop water requirements. Here, we will present a study on understanding drivers of the complex and evolving cropping systems in Southwest Michigan using satellite data and Flux towers. The study area encompassed Michigan’s southwest agricultural district, which consists of eight counties. We used a surface energy balance model (SEBAL) to estimate time series of evapotranspiration (ET) in the region, which gave us an understanding of the dynamics of water use in agriculture as a function of time.

Variable impacts of habitat context on monarch butterfly (Danaus plexippus L.) oviposition and egg survival

Andrew Myers, Michigan State University

The eastern North American population of monarch butterflies (Danaus plexippus L.) has become a major conservation concern as overwintering populations in Mexico have declined dramatically during the past two decades. Efforts to increase monarch populations have included restoring milkweed host plants in the breeding range lost through the adoption of herbicide-resistant row cropping systems. To maximize  conservation efforts, it is important understand which habitats are most attractive to egg-laying monarchs and support the greatest survival of eggs and larvae. Through two summers of sentinel host plant experiments, we found oviposition site selection varied between years with corn as the most attractive habitat in 2016 and prairie in 2017. We found a strong effect of predation on egg survival, with a sharp drop during the first 24 hours and variable, but at times particularly low survival in prairies. Our findings have important implications for monarch conservation and indicate that grasslands targeted for milkweed host plant restoration may support very low monarch butterfly survival compared with milkweed historically growing in corn fields.

Watershed land use differences correlated with differences in diatom taxonomy in streams in the Huron River Watershed

Rob Sulewski, University of Michigan

Changes in land use are a major cause of ecological change, and these differences can be manifest at the most fundamental trophic levels such as in biofilms in streams.  In this preliminary study, we restricted our investigation to diatoms because they constitute a substantial percentage of biomass in biofilms, and have been successfully used in the past to evaluate ecological conditions in streams.  We wanted to determine whether the diatom populations differ among the streams, and what environmental factors related to land use are correlated with the differences. We placed ceramic tiles for three weeks in six streams all located in the Huron River Watershed, but with unique catchments (urban, agricultural, and mixed:  two from each catchment type). We then counted the diatoms to genus growing on the tiles from each stream, and measured six environmental variables (conductivity, temperature, stream velocity, pH, percent impermeable surface, and percent agricultural and urban catchment area) in each stream. As expected, stream velocity, percent total impervious surface, and percent urban and agriculture catchment area were associated with the urban streams, and these variables were negatively correlated with the mixed and agricultural streams.  We found significant differences in the taxonomic compositions of diatoms in the streams, and in streams dominated by an urban environment, we found greater generic diversity than in streams in a mixed environment and those in a primarily agricultural environment, most likely due to the greater non-equilibrium disturbances (scour due to higher stream velocities) to which the urban streams are subject. We also found differences in diatom guilds (high profile, low profile, and motile) among the streams and stream types, although the low profile guild dominated in all streams and stream types.  The greater percentage of the motile guild in the urban streams is probably due to their ability to move to more hospitable zones, giving them a competitive advantage over other guilds. We conclude that differences in urban streams from non-urban streams are likely related to water flow rates in the urban environment.

Presenters