Grazing Ecology: Conservation Benefits of Ruminant Agriculture

Transcription

1 Animals in the Food System Conference Kellogg Biological Station Hicky Cners, Michigan November 2-4, 24 Michigan State University 312 Natural Resources Building East Lansing, MI

2 Abstract Conservation benefits animal agriculture begin with the role that fages play in soil erosion control and farm conservation planning, but they don t have to end there. Research in Wisconsin and other areas suggests that well-managed grazing can be used to control invasive weeds, reste oak savannas, enhance trout stream habitat, and provide high quality nesting cover f grassland birds. Many plant communities evolved with herbivy and are me productive when grazed. With an increased understanding the role ruminants play in ecological processes, we can use livestock grazing to help reste healthy functioning ecosystems in agricultural areas. Wellmanaged grazing can provide conservation benefits and a reasonable farm income on the same acre. Three key players need to come together to make this happen: the natural resources community, the agricultural research establishment, and farmers themselves. Currently, there are no economic drivers to bring attention and research dollars from the agricultural establishment. The natural resources community is not yet convinced that cattle grazing can be managed to benefit the environment. While there are many farmers with an interest in conservation, there are few with the knowledge and skill set they need to maximize the conservation benefits managed grazing. I believe that livestock grazing is critical to the long-term sustainability agriculture in the Nth Central region. Studying and documenting its potential f enhancing habitat is one way to help safeguard its long-term viability. Edits Note: This document contains the Powerpoint slides used by the presenter. If you wish to make this document larger on your computer screen to better view the slide detail, you may change the magnification by selecting the View menu, and then Zoom To. Select type in your desired magnification and then select OK. Animals in the Food System Conference November 2-4, 24 Michigan State University 2

3 With this presentation, I d like to highlight some the conservation opptunities we have when wking with grazing systems in the Nth Central and Ntheastern United States. I would also like to point out some challenges we have as well, but I think the benefits retaining livestock in our farming systems outweigh the risks. I ll be talking about some wk that we have done in Wisconsin, wk by my own colleagues and me, as well as other projects in the region. What we did in our research project was to wk toward overcoming some the challenges we face by bringing together not only researchers but also the farmers who need to adopt these systems and the environmentalists who have valid concerns about agriculture s environmental issues. I think we have a great opptunity to bring environmentalists into the grass farming movement, but there are some mindset barriers we need to overcome. We have been talking a lot today about management. I think everyone that we ve heard speak today emphasized the imptance management in keeping livestock agriculture strong and pritable. I would argue that the conventional wisdom on the detrimental aspects livestock agriculture is a result po management. It s certainly not the animals fault, and it s not a given that livestock agriculture has a negative impact on the environment. The problems we ve had are a result lack knowledge and lack attention to management skills. We can do a lot better. We can also provide evidence that animal Ruminant Agriculture and the Environment: agriculture has a key role to play in environmentally Highly erodable soils in in the the dairy belt belt Iowa sound agriculture in this region. This graph divides Iowa Michigan Michigan agricultural land in the Great Lakes States into Ohio Ohio Minnesota prime land with no erosion concerns, and two other Minnesota New New Yk Yk categies f which crop agriculture must be Pennsylvania Pennsylvania Wisconsin Wisconsin restricted because slope other erosion % % 2% 2% 4% 4% 6% 6% 8% 8% 1% 1% potentials. In this region, prime agricultural land is Class Class I I & II II Class Class III III & IV IV Class Class VI-VIII VI-VIII really a very small percentage the total amount the land area. A great deal our farmed land in the region, some 3 to 5%, is highly erodable and needs the protection that perennial fages provide. Our landscape includes 1 to 4% land in classes six through eight, which is basically unsuitable f annual row crops, but can possibly be safely used f pasture. Animals in the Food System Conference November 2-4, 24 Michigan State University 3

4 In other wds, if we want to have agriculture in this region, we need a fage-based agricultural system to conserve the soil. We just need to figure out how to manage it properly. Of course, there has also been discussion about how much federal money goes into the Ruminant Agriculture and the Environment: farm programs USDA spending on on soil soil conservation to promote conservation soils. Fages provide soil conservation benefits at little cost. If conservation is incpated into the farming system, if you can do conservation and pritable agriculture on the same acre, it is a much easier sell to farmers. A lot the wk we did looked at wildlife habitat Relationship between Fage Acres quality agricultural systems and how we can & Grassland Bird Populations promote wildlife benefits as well as soil conservation benefits. This graph shows changes in farmland cropping practices over the last fty so years. Gradually, we ve lost a lot acres fages in the region, and I have overlaid data Fages Fages Rowcrops 1 Rowcrops showing rapid declines in grassland bird 1 Western 5 1 Western 5 Meadowlark Meadowlark populations over the same period. This happens to be the western meadowlark populations in Wisconsin, but all grassland bird species are experiencing similar declines. You can see there is a parallel with the fage base in this region. Although there are several facts involved in these declines, this crelation tells us that it isn t agriculture in itself that has reduced habitat quality, it s the type agriculture we are doing. These birds were surviving quite well with the fage-based systems that we had up until the 196s in this area. Reversing the losses hay and pasture acres in the region can contribute to habitat quality f these species. Acres X 1 Acres X 1 # Birds/Survey # Birds/Survey Wking Landscapes Agricultural Conservation Goals: Goals: Goals: Goals: Incpating Can Can we we Utilizing habitat habitat value value find find a livestock into into pritable compromise grazing as as agricultural? a tool tool f f systems habitat habitat restation I guess the question I d like to pose to the group is: Can we create what we call a wking landscape that can provide the farmer with a reasonable income while also providing conservation benefits? Can we incpate habitat quality into a pritable agricultural system? And from the conservationist s perspective, can we use livestock grazing as a tool to improve the habitat f wildlife? Animals in the Food System Conference November 2-4, 24 Michigan State University 4

5 A good place to begin this discussion is to look at Co-Evolution agriculture as an ecosystem, which it certainly is. Ruminants & Cows are uniquely adapted to feed themselves by Grass grazing grass, and the grass plant has actually evolved to be grazed. They are both parts one ecosystem. We can look at the native prairies Nth America Ruminants as a model f in in the Ecosystem our agroecosystem. Current research suggests that the prairie was Climate Fire The Prairie maintained by early Native Americans who Ecosystem managed both fire and grazing f their own purposes and managed to maintain a healthy Early ecosystem in the process. Grazing Humans There is evidence that ecosystem processes occur in our temperate pastures that are similar in function to natural grasslands throughout the wld. Both temperate pastures and natural grasslands have herbives consuming a sizeable proption the plant biomass produced in any given year. Temperate pastures range from 5 to 75% consumed, while natural grasslands average 2 to 6% consumed by herbives, including about 25% consumed by underground invertebrates. Ruminants in in the Ecosystem Temperate Pastures 5 5 to to 75% 75% net net primary primary production production intensively intensively managed managed temperate temperate pastures pastures is is consumed consumed by by herbives. herbives. Natural Grasslands 2 2 to to 6% net net primary production natural grassland systems is is consumed by by vertebrate and and invertebrate herbives. (In (In both both systems, systems, up up to to 25% 25% consumption consumption is is by by underground underground invertebrates) invertebrates) Grassland Net Primary Productivity and Energy Capture Efficiency Kcal/m2 Kcal/m2 Grazed Grazed Ungrazed Ungrazed Above Above Ground Ground Below Below Ground Ground Adapted Adapted from from Sims Sims and and Singh, Singh, Net Net Production Production (Kcal/m2) (Kcal/m2) Grazed Grazed Ungrazed Ungrazed Efficiency Efficiency (%) (%) We also find when we look at natural grassland systems that those that are grazed are actually me productive in terms primary plant production - by 6-7% - than ungrazed, idle grasslands. So grazing plays an imptant role in renewing those grasses, allowing new growth, and promoting nutrient cycling. Animals in the Food System Conference November 2-4, 24 Michigan State University 5

6 So we can think about grazing as a natural component healthy grasslands. Then the question becomes, can we manipulate livestock grazing to achieve resource management goals? Can we include it as a tool in the management toolbox? In contrast to fire, the tool choice f many grassland managers in this region, grazing is relatively selective. It is not necessarily better wse than other management tools, but can be used to accomplish different objectives. As a management tool, livestock grazing is is relatively selective Using Grazing to to Control Invasives species. Here s one example how we might use this tool. One the things we are looking at is to use grazing to control invasive plants. The species here is reed canary grass, which, if you are a grazier agronomist, is a productive pasture component. If you are a natural resource person, it is one the most invasive species we have to deal with in wetlands across the Midwest. Its growth creates a dense mat vegetation, and where it grows, it tends to smother out many native plant One the studies that we did looked at grazing Using along trout streams in southwestern Wisconsin. Grazing to to Control Invasives We studied four treatments: two buffer strip 8 Grazed 8 treatments, grassy and woody; a well-managed Grazed sites sites 7 had 7 had me me native native 6 rotational grazing system; and unrestricted 6 grasses grasses and Managed Grazing and Managed Grazing 5 sedges 5 sedges and Unrestricted Grazing and Unrestricted Grazing uncontrolled cattle access. As you can see in the less less reed 4 reed 4 canarygrass, canarygrass, 3 3 an center set bars the reed canary grass was the an invasive invasive 2 species 2 species in in riparian 1 riparian 1 dominant species in the grassy buffer strips at 4% areas areas and and wetlands. wetlands. All All Reed Reed Native Native the total compared to fewer than 5% f the Canarygrass Canarygrass grazed sites. The grazed sites had a significantly higher proption native sedges and rushes and other grass-like species (over 2% f well-managed grazing versus just over 1% f grassy buffer strips). This was because the cattle preferentially selected the reed canary grass over these other species, giving them a competitive edge. Percent Percent Plant Plant Canopy Canopy Animals in the Food System Conference November 2-4, 25 Michigan State University 6

7 Here s another example using grazing Scottish Highland Clear management to address conservation goals. This Oak Savanna one involves resting habitat structure. Oak Undergrowth savanna was once the most common grassland in Wisconsin; now it is our most endangered ecosystem. F ecosystems like the oak savanna, Trade f/balance: Trade f/balance: Reduce/eliminate shrub layer Reduce/eliminate shrub layer Maintaining gaining herd Maintaining gaining herd the structure is one the defining components weight weight Minimal impact on soil erosion Minimal impact on soil erosion the system. It is characterized by widely scattered Long-term Long-term Maintain grazing burning Maintain grazing burning Tree thinning Tree thinning large oak trees with shade-tolerant prairie species underneath. Many oak savannas have become overgrown over the decades. A study done by the University Wisconsin, Wisconsin DNR and several private livestock farmers used Scottish Highland, a browsing animal, to go into these overgrown oak savannas. We ve found that these Highland cattle will actually consume invasive species such as prickly ash and multifla rose and recreate the habitat structure characteristic the oak savanna. Here is one me example how livestock grazing Hned Lark Hned Lark 12 Upland Sandpiper 12 Upland Sandpiper Grasshopper Sparrow Grasshopper Sparrow Eastern Meadowlark can create a me favable habitat structure. 1 Eastern Meadowlark 1 Bobolink Bobolink Henslow's Sparrow Henslow's Sparrow 8 Sedge Wren These are some data from Missouri. We 8 Sedge Wren 6 6 mentioned grassland birds earlier. This most 4 4 rapidly declining group wildlife species in Nth 2 2 America is struggling as a result habitat loss. As - - 4" 4" 4" 4" - - 8" 8" 9" 9" " 12" >12" >12" Idle Idle Grazed we saw in a previous slide, they don t need prairie Grazed Vegetation Vegetation Height Height to survive and their populations were maintained on Grazing Modifies Grassland tame pastures and fages f many decades. Bird Habitat They don t really care if they have native plants to nest in; it s the habitat structure they are looking f. If you look across the vegetation heights in this chart, you can see that the majity these species actually prefer shter, grazed habitat to unharvested, idle grasslands. As you get up into the taller, idled grasslands like you would find in a CRP field, a lot those species will drop out. There are a few that need that tall, dense habitat, but most them are actually adapted to me structurally diverse grassland created by grazing burning. Total Total # # Birds Birds Animals in the Food System Conference November 2-4, 25 Michigan State University 7

8 Effect Habitat Patch Size on on Grassland Birds % sites where species was observed Savannah Savannah Sparrow Sparrow Eastern Eastern Meadowlark Meadowlark Bobolink Bobolink < < 55 acres acres 55 to to acres acres > > acres acres The other issue f a lot these species is the size the habitat patch. That is where our grass-based farms can really fer a benefit in providing the acreage pasture grassland that these birds need. This graph shows that as the pasture gets bigger, me species and me breeding pairs will be attracted to nest there. We found that, contrary to conventional wisdom, the narrow crid habitat created by a buffer strip has little no value to most the declining grassland bird species. The usually less than five acre habitats provided by the buffers were populated primarily by red-winged blackbirds, while the declining species were found in the upland areas pastures adjacent to streams. Grassland Bird Use Buffers and Pastures # birds/survey # birds/survey 3 3 Grassland Species Declining Grassland Species Non-Grassland Species Grassland Species Declining Grassland Species Non-Grassland Species Streamside Upland Streamside Upland Streamside Upland Streamside Upland Streamside Upland Streamside Upland Continuous Rotational Grassy Buffer Making It is clear that grazed pasture can provide Compromises: appropriate habitat structure f grassland birds. Nest Survival What you need to look at, in addition to providing Tilled Tilled Cn Cn the appropriate structure and acreage, is No-till No-till Cn Cn Alfalfa management and how it impacts the species that Alfalfa Continuous Continuous Pastures Pastures you are wking with. Another study that we did to Rotational Rotational Pastures Pastures Idled assess the impact grazing management on Idled Paddocks Paddocks CRP CRP grassland bird nest survival found that rotational pastures will Total Total Nests Nests Estimated Estimated Nest Nest Survival Survival attract as Making Compromises: many birds as CRP fields, but the nest survival Creating a Nesting Refuge the number young produced on those pastures was about half what we got from the idled paddocks because the trampling and disturbances the nests. F this project, we Warm Warm Paddocks used a proposal by one the farmers we wked with. He wanted to try setting aside some acres in Cool Cool Paddocks the middle the pasture system as a refuge during the nesting season. Woods Woods Animals in the Food System Conference November 2-4, 24 Michigan State University 8

9 Rep 1 Rep 2 Seeded in 1998 Rep 1 Rep 2 Seeded in Acres Warm Pasture 28 Acres Warm Pasture Grazed by bison starting in 22. Grazed by bison starting in 22. Strips are solid stands : Strips are solid stands : Big (1 lb/a) Big (1 lb/a) Little (1 lb/a) Little (1 lb/a) Indiangrass (1 lb/a) Indiangrass (1 lb/a) Switchgrass (5 lb/a) Switchgrass (5 lb/a) Sideoats Grama (1 lb/a) Sideoats Grama (1 lb/a) Mixture 2 lb/a each Mixture 2 lb/a each (except switchgrass) (except switchgrass) In field #21 (17 a), each strip is In field #21 (17 a), each strip is 5 feet wide and 1 feet long. 5 feet wide and 1 feet long. In field #22 (11 a), each strip is In field #22 (11 a), each strip is 7 feet wide and 1 feet long. 7 feet wide and 1 feet long. Rep 3 Switchgrass Rep 3 Switchgrass Mixture Mixture Big Big Sideoats Grama Sideoats Grama Indiangrass Indiangrass Field #21 Field #21 N N Grazing Ecology: Conservation Benefits Ruminant Agriculture The best fages to use f these refuge areas are Warm Pastures and and the the Nesting the native warm season grass species. The Cool Cool seasons Native seasons Native grasses grasses ready ready to to graze Legumes graze Legumes challenge with our cool season pasture systems is Warm Warm seasons seasons Nesting Nesting that, when these cool season grasses are growing very quickly and we re rotating very rapidly through the paddocks is the same time that most the birds are nesting. Their peak nesting season occurs when we re returning to each paddock within Past Past peak peak nesting nesting two to three weeks, too sht an interval to allow a period period full nest cycle from construction to fledging. That is why we see such low nest survival. A refuge set aside area native grasses fits with this system. Native grasses mature me slowly and are not really ready to graze until most the birds are done nesting. April April May May June June July July August August September September October October November November This is an area on-going research. Jim Pease, a wildlife biologist at Iowa State, is looking at grassland bird response to a native/non-native grass pasture system, and there is some wk going on at Michigan State evaluating grazing management strategies with natives. This slide shows a study site in Wisconsin where we have planted strips the different native species and we are grazing across them to look at both animal preferences as well as the tolerance each grass species to grazing pressure. Using Native Prairie in in Grazing Systems Gegia Derrick/Jim Atten Farm Gegia Derrick/Jim Atten Farm Mixture Switchgrass Little Little Big Big Mixture Switchgrass Little Little Sideoats Grama Sideoats Grama Indiangrass Mixture Mixture Sideoats Grama Sideoats Grama Switchgrass Big Indiangrass Switchgrass Big Indiangrass Little Field #22 Little Field #22 Indiangrass Leftover seed Leftover seed Animals in the Food System Conference November 2-4, 24 Michigan State University 9

10 Jun 21-Jun 19-Jul Jul Big Indiangrass Little Big Indiangrass Little Results: Crude Protein (%) Mix Mix Side Oats Switchgrass Grand Side Oats Switchgrass Grand Grama Average Grama Average The key to this wk is to keep both the conservation and production components in mind as we exple these systems. Our study includes fage nutritional quality evaluation the warm season grasses. As you can see from this graph, crude protein levels in the grasses vary among species and with grazing timing. We found that, f the most part, warm season grasses have adequate levels protein f most classes livestock other than lactating dairy cows. Another nutritional parameter imptance to livestock farmers is total digestible nutrients. F this component, all the species had adequate levels, even f high demand dairy cows. SW SW BB BB Range Range Lactating Lactating Dairy Dairy Beef, Beef, Sheep, Sheep, Non-Lactating Non-Lactating Dairy Dairy Results: Total Digestible Nutrients (%) Jun 21-Jun 19-Jul 19-Jul SW SW Lactating Lactating Dairy Dairy All All Other Other Livestock Livestock Big Indiangrass Little Big Indiangrass Little Mix Mix Side Oats Switchgrass Grand Side Oats Switchgrass Grand Grama Average Grama Average MX MX Range Range Improving Riparian & Aquatic Habitat Grassy Grassy Buffers Managed Buffers Managed Grazing Grazing Another project that I touched on briefly involved looking at well-managed grazing as a potential best management practice in riparian areas. As I mentioned befe, we looked at woody and grassy buffer strips, managed grazing, and unrestricted cattle access. Unrestricted Unrestricted Access Access Woody Woody Buffers Buffers Animals in the Food System Conference November 2-4, 24 Michigan State University 1

11 These graphs summarize our findings concerning the physical habitat created by the four treatments. We found that well-managed grazing provided protection from bank erosion equivalent to that grassy buffer strips and better than woody buffer strips. We also looked at in-stream habitat f fish and again found that managed, rotational grazing created habitat similar to grassy buffer strips and better than woody buffer strips. Improving Aquatic Habitat Bank Erosion Index: Aquatic Habitat Index: 9 Bank Erosion Index: 9 Aquatic Habitat Index: Higher values indicate 9 Higher values indicate greater Higher values indicate greater 8 Higher values indicate 8 greater soil loss. 8 habitat quality. greater soil loss. 8 habitat quality Unrestricted Grazing Managed Grazing Unrestricted Grazing Managed Grazing Unrestricted Grazing Managed Grazing Unrestricted Grazing Managed Grazing When we looked at the response the biological Fish Community: community to these habitat treatments, we saw a Index Biotic Integrity different response. The Index Biotic Integrity Unrestricted Grazing 9 Unrestricted Grazing (IBI) is a numerical scing system that fishery Managed Grazing 8 Managed Grazing biologists use to rate aquatic systems in terms fish community health. As this slide shows, although the managed grazing sites had similar habitat quality to the buffer strips, this didn t 1 1 translate into similarly healthy fish communities. The grassy buffer strips had significantly healthier fish communities than any the other treatments. It should be noted though, that even the grassy buffer sites rated only fair (3 on a 1 point scale). This result is not surprising if you look at the bigger picture a watershed. The health the biological community is going to be primarily determined by the overall health the watershed. We can collect data and analyze it in a way that accounts f treatment versus watershed influences. Animals in the Food System Conference November 2-4, 24 Michigan State University 11

12 Comparative Influence Local and Watershed facts Watershed Watershed Local Local Bank Bank Erosion Erosion Aquatic Aquatic Habitat Habitat Physical Attributes Trout Trout CPE CPE IBI IBI Sce Sce Biological Attributes By collecting data upstream the treatment sites, we were able to quantify the respective influences that both the treatment and the watershed had. As you can see, the physical attributes (e.g. bank erosion and aquatic habitat) are me readily affected by management, whereas the biological attributes, like the IBI, are me heavily influenced by the health the entire watershed. We can t expect to improve the overall health a watershed unless a majity stream miles are protected with best management practices In der to provide a significant conservation benefit on agricultural land, we need to think on a Connecting landscape scale. Biologists Laura and Dana the Dots: Jackson have outlined this notion in their recent Landscape book titled The Farm as Natural Habitat. This Scale slide depicts the notion the agricultural Opptunities landscape as a patchwk habitat types. As long as there are high quality habitat patches in From: From: Laura Laura Jackson & Dana high enough proptions, the ability the Dana Jackson, The The Farm Farm as as Natural Natural landscape to suppt wildlife and other Habitat Habitat conservation values is intact. As the landscape shifted over time, prairie hay and pasture was gradually displaced by row crops and other less beneficial crops. As the high quality patches became smaller and me isolated, their value declined. Only by using the perennial crops associated with livestock-based agricultural systems do we have the potential to reverse this trend without taking substantial acreages out active agriculture. When we wk on conservation and Conservation Goals environmental issues, we need to consider our Soil Soil Erosion Erosion Ecological Ecological Ecosystem Wildlife conservation goals. We have a range Wildlife Habitat Ecosystem Water Habitat Water Quality Quality Function Function Restation Restation Energy Energy Flow Sod Flow potential objectives f each farm parcel Sod Cover, Habitat Cover, Habitat Mineral Mineral Cycling Plant Cycling Plant & Necessary & Necessary Reduced Reduced Ag Structure Ag Structure Animal Features Animal Features Chemical Chemical Inputs Water Water Cycling Inputs Patch Patch size Cycling Biodiversity size Biodiversity Biodiversity land. Our options f a goal controlling soil Biodiversity Farm Farm Scale Scale Field Field Field Field Farm Farm Landscape Landscape Landscape erosion will be different from those f protecting Landscape Warm Warm Warm Warm A A Diverse Diverse Array Array Native Native local Appropriate local grassland birds, f example. We ll probably be Appropriate Cool Cool Cool Cool Plant Plant and and ecotypes ecotypes & Species & Species Animal Animal Species Species species species looking at different landscape scales and Compatible Compatible with with wellmanaged wellmanaged possibly different grassland types. Across all grazing? grazing? the potential conservation goals f agricultural land and/ grassland management, wellmanaged grazing is not only compatible but may be a valuable tool f maximizing conservation benefits. Animals in the Food System Conference November 2-4, 24 Michigan State University 12

13 It is a matter developing the proper management approaches and considering grazing behavis, modifications in stocking rate, rotation length, grazing residual, and seasonal timing. I would like to leave you with the point that while considering conservation goals on private land, we can t lose sight the fact that the farmer needs to be pritable in der to stay on the land. Management is is the key Livestock Livestock species species grazing grazing behavi behavi Flexibility Flexibility stocking stocking rate, rate, rotation rotation length, length, etc. etc. al al timing timing grazing grazing Post Post grazing grazing canopy canopy height height Pritability Pritability BisonRidge Ranch Gegia Gegia Derrick, Derrick, Propriet Propriet The The Landscape any any farm farm is is the the owner s ptrait himself Aldo Aldo Leopold Aldo Leopold talked a lot in his writings about a land ethic. I think a land ethic still exists among farmers. We just need to rekindle it and fuel it with good, ecologically sound infmation. Putting land management knowledge and skills in the hands a caring farmer is probably the most effective conservation investment we can make. A livestockbased system has the greatest potential f longterm economic, social, and environmental sustainability agriculture in the region. Animals in the Food System Conference November 2-4, 24 Michigan State University 13