The Ecological Society of America www.frontiersinecology.org
Ecosystem services • Processes by which the environment produces resources • timber • clean water • habitat for fisheries • pollination of native and agricultural plants • AMES • Arthropod mediated ecosystem services • US annual value ~$8 billion dollars (Losey and Vaughn 2006)
Beneficial insects • Pollinators and Parasitoids • Natural enemies of insect pests • > 100,000 invertebrate species worldwide • E.g.: bees, moths, butterflies, beetles, flies, wasps • Require nectar and/or pollen from flowers • Specific habitat and foraging needs • Most flowering plants require pollinators. • Significant role in >150 food crops in the US • E.g.: almonds, apples, alfalfa, melons, plums, squash • Almost all fruit and grain crops
Changes in farmland • Farmland being sold for development • More invasive plant species • The focus on bio-fuels
Farmland being sold for development • More farmland is being sold for development. This is reducing land that native plant species grow on. Bees, predators, and parasitoids require these plant species for survival.
More invasive plant species • There are more invasive plants today than there were 25 years ago. Invasive plants are taking over land used for pasture or crops. This leads to less plants that beneficial insects need to survive.
The focus on bio-fuels • As the demand for bio-fuels increase, the amount of land planted in corn has increased. This means less landscape diversity and also intensifies pesticide use. When pesticide use is increased both target and non-target insect and plant populations are reduced. This means beneficial plants and insects will be dramatically reduced.
Almost all beneficial insects require food in the form of nectar and/or pollen from flowers • This promotes optimal survival and high levels of reproduction • Success should be measured as an increase in biodiversity as well as crop production
Beneficial insects on native Midwest prairie plant flowers: • Syrphid fly • Adults feed on pollen and nectar • Larval stage feed on aphids and other insects
Soldier Beetle • Adults feed on grasshopper eggs as well as aphids and other insects • Supplement diet with pollen and nectar • When primary hosts or prey are • not available, these predators require alternate • hosts or prey to complete their lifecycles • Ecosystem must be in balance for long term AMES, survival or predator and prey important
Leafcutter bee • Very efficient pollinators • Only gather small amounts of pollen per trip to the flower which results in frequent trips, distributing pollen each instance • To maximize reproduction, bee species require flowers within their foraging range throughout the season • Must have enough plants in the area to support bees even after the crops are harvested
Key questions about rebuilding habitat for beneficial arthropods • What types plants should be introduced or conserved in order to attract beneficial arthropods? • Increase beneficial insects • Minimize introduction of new harmful species • How should the insects or plants be distributed/introduced? • Slowly/quickly • Near/far from crops
Habitat management efforts to support beneficial insects are based on the establishment of flowering plants to provide pollen/nectar through the majority of the year • Which landscape will be most likely to conserve beneficial insects and provide pest control and pollination services?
Low complexity – impoverished/depleted insect populations • High complexity – high insect population that is not easily increased • Medium complexity - the addition of flowering plants provide resources that can be exploited by organisms to increase their populations
Native Plants to Support AMES • Research mostly on a few species • Native perennials are a good alternative • Local Adaptation • Habitat Permanency • Increased Native Plant Diversity • Minimize Recurring Costs
Potential Drawbacks to Native Plants Long establishment period Availability of seed More research needed Collaboration needed
Screening Native Plants Screening native plants involves evaluating plants based on the number of beneficial arthropods on and around plants. Specific species are recommended based on bloom period and the relative adaptation to the environment. Native plants are important in agricultural landscape because they outcompete non-native plants
Screening Native Plants In 2004 and 2005 plants were screened that were native to Michigan. A total of 48 species were screened, with 43 being native and 5 being non-native to the area. Of these 48 plants, 26 were considered highly ranked when evaluated during the blooming season. Ranking was based on the number of predators, parasitiods, and native bees found on or near each plant.
Screening Native Plants • These plants provide an overlapping sequence of blooms during growing season. • The native plants frequently had more beneficial arthropods on or around them than the non-native plants. • More insects responded better to larger flowers as compared to plants with smaller flowers. • This means that large floral displays should be considered when screening for native plants
Screening Native Plants • These screenings suggest that targeted planting can contribute to natural pest control and crop pollination • Native flowering can also provide food and shelter for other wildlife, including threatened birds, mammals, and butterflies. • The planting of large areas of native flowers can also increase biodiversity in the ecodystem.
Landscape context and arthropod conservation plantings Landscape context-is the aspect of a land characteristic of a particular region Arthropod conservation plantings-programs aimed at enhancing an area to sustain a high population of beneficial arthropods
Benefit of arthropods? • They act as pollinators • They help with biological control • Pest control which reduces use of pesticides on farmland thereby reducing waste runoff which harms the environment
Landscape variables that support beneficial arthropods: • Habitat complexity • Simplified, Intermediate or Highly complex • Quality-how beneficial the native plants are to arthropods • Patchiness-multiple small patches of conservation land are better than one huge patch
Crop fields are ephemeral habitats • Ephemeral-means lasting a short time • Anthropogenic disturbances-disturbances caused my man: • Tillage of land • Pesticide application • Harvesting • These habitats require frequent recolonization and surrounding conservation areas can house the beneficial arthropods during this disturbance
There are many levels of landscape complexity within the U.S. • Landscape context is a primary driver of the ability of conservation efforts to deliver intended benefits • Three levels with two extremes: • Simplified-these lack infrastructure needed for some species • Highly complex-these won’t benefit from conservation plantings • Intermediate-this is the level that benefits most from conservation plantings
Landscape-ecosystem service hypothesis • This states that Arthropod Mediated Ecosystem Services (AMES) are unlikely to be enhanced by adding resources in highly simplified landscapes, because species pools are too impoverished to respond • Additional resources will increase AMES in landscapes of intermediate complexity, where the ecosystem will have a positive response to management
Conclusions • Landscape Changes • Agriculture • Profit Maximization • Yield • Production practices • Pesticides • Herbicides • Pesticides • Urban • Expansion
Conclusions • Conservation Programs • FSA • State Acres for Wildlife (SAFE) • NRCS • NRCS-managed Conservation Security Program • Plant Species • Native • Large flowers • Perennial
Conclusions • Beneficiaries • Ag producers • Crop yield • quality • Society • Environmental concerns