Combining data from state and national monitoring surveys to assess large-scale impacts of agricultural policy

Nusser, Sarah M.; Clark, William R.; Wang, Junyuan; Bogenschutz, Todd R.

doi:10.1198/108571104x4441

Cited by 6 publications

(13 citation statements)

References 11 publications

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“…Our projection matrix estimate is consistent with the annual rate of increase of 4% to 7% per year that we observed on roadside counts during 1990 to 1994 in the Kossuth and Palo Alto areas (T. Bogenschutz, unpublished data). The projection estimate is also similar to the 4% rate of increase from 1988 to 1995 that Nusser et al (2004) estimated from time series analyses of roadside counts throughout the Northern Row Cropland region of Iowa. Deterministic projections are known to be positively biased but have proven to be useful, even preferable to fully stochastic models, for understanding population behavior when sampling duration is limited or vital rates are highly variable (Doak et al 2005a).…”

Section: Discussionsupporting

confidence: 72%

Sensitivity Analyses of a Population Projection Model of Ring-Necked Pheasants

Clark¹,

Bogenschutz

Tessin

2008

J Wildl Manage

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A large literature exists on population dynamics of ring‐necked pheasant (Phasianus colchicus) in North America, but there has not been an attempt to formulate a matrix model nor a sensitivity analysis of the relationships between vital rates and population finite growth rate (Λ) that can be used to guide management. We summarized demographic data available from a 5‐year field study in Iowa, USA, collected in Kossuth County (low composition of perennial habitat) and Palo Alto County (high composition of perennial habitat) into a 2‐stage (young and adult) matrix projection model. We estimated Λ1 (the dominant eigenvalue of the deterministic matrix), the stable age distribution (ω), relative reproductive value vector (n̈), other demographic parameters, and Λiid, a bootstrap estimate of growth that includes interannual variation in life history parameters. We analyzed the relative importance of vital rates on population growth rate using sensitivity and elasticity of both matrix elements and lower‐level parameters such as winter survival and nest success. We first characterized general life history using averaged data from both areas and all years that yielded Λ1 = 1.086, and a stable stage distribution of. Minimum success of the initial nesting attempt (H1) that would maintain Λ ≥ 1 under average conditions was estimated to be 42%. Changes in Λ1 were most sensitive to survival of chicks during brood rearing (SB), followed in importance by survival during the subsequent winter (SW), followed by H1. We followed the general analyses with analyses that helped us to focus on the differences in the landscapes of northwest Iowa. Λiid was ≥1 in only 9% of simulations of data from Kossuth whereas estimated Λiid was ≥1 in 88% of simulations from Palo Alto. Our analyses of the relative importance and interactions between SB, SW, and total recruitment (M, including H1 and renesting), if combined with data more specific to a local area, would guide management aimed at affecting multiple life history stages whose relative importance will vary across the landscape.

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Section: Discussionsupporting

confidence: 72%

Sensitivity Analyses of a Population Projection Model of Ring-Necked Pheasants

Clark¹,

Bogenschutz

Tessin

2008

J Wildl Manage

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“…Riley () found county‐level August pheasant indices were positively related to Iowa CRP enrollments, with counties having the smallest proportion of non‐CRP grasslands showing the greatest response. Similarly, Nusser et al () found pheasant trends in Iowa responded positively to CRP only in regions with low initial perennial cover, but an effect was not detected in the statewide trend. Hiller et al () found evidence that a declining long‐term trend in Nebraska's statewide rural‐mail‐carrier–derived pheasant index became less severe after CRP enrollments began in 1986.…”

Section: Pheasant Responses To Ccpsmentioning

confidence: 87%

“…The large‐scale models of Nusser et al (), Nielson et al (), Jorgensen et al (), Pabian et al (), and Stuber et al () all suggest average pheasant abundance in a CCP enrollment can be influenced by the land cover of the surrounding landscape. We therefore recommend focusing enrolled acres within defined geographies and placing those “focus areas” in the most pheasant‐friendly landscapes available within a given state, assuming the primary management objective is to maximize population size.…”

Section: Recommendations For Ccps and Associated Researchmentioning

confidence: 99%

Pheasant responses to U.S. cropland conversion programs: A review and recommendations

2018

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We describe ring-necked pheasant (Phasianus colchicus) habitat needs, historical U.S. cropland conversion programs (CCPs), research documenting pheasant responses to these programs, and make policy recommendations for programs to more efficiently elicit such responses. Cropland conversion program principles supported in the pheasant literature include establishment of an initial seeding, a multiyear contract structure, prohibition of mowing during the nesting season, promotion of forbs in seedings, provision of large-block enrollments options, and inclusion of midcontract management. These principles are compatible with the habitat needs of many other grassland bird species. We therefore recommend the Conservation Reserve Program (CRP) and any future CCPs retain these foundational aspects. Initial plantings of higher diversity seed mixes have become prioritized over time, but we note whatever increase in average habitat quality these standards achieved, it was not enough to prevent widespread pheasant declines following more severe statutory limitations on CRP acreage enrollments beginning in 2008, coupled with long-term declines in other habitat types (e.g., hay, pasture, small grains). When faced with a trade-off, we thus recommend emphasis of enrolled area over quality, provided enrolled herbaceous tracts provide adequate structure (!3 dm of 100% visual obstruction) and canopy cover components (>5% forbs and >5% bare ground). Efficiencies may also be gained by altering initial seeding rates, offsetting program costs using grazing income, allowing more discretion in the use of midcontract management, and prioritizing enrollments in focus areas. Individual states, U.S. Department of Agriculture, and bird conservation joint ventures should work cooperatively to share data and perform return-on-investment-oriented research at multiple spatial scales concerning the effects of CCPs on pheasants. Ó

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“…Given the concurrent loss of alternative reproductive habitats from 1987–1997 and the disturbance of roadsides and some CRP fields, the lack of a strong range‐wide increase in the Minnesota pheasant index is not surprising. Nusser et al (2004) also failed to find a strong range‐wide increase in Iowa, and Nielson et al (2006) reported a weak, negative population trend in nine states during 1987–2005. However, lack of a range‐wide increase should not be interpreted as evidence that the CRP did not have a positive effect on local pheasant populations.…”

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confidence: 99%

Using regional wildlife surveys to assess the CRP: scale and data-quality issues

Giudice

Haroldson

2007

J Field Ornithology

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Evidence that the Conservation Reserve Program (CRP) has resulted in large‐scale increases in populations of grassland birds is limited. Detecting large‐scale CRP effects is difficult because agricultural landscapes are complex, dynamic systems where many concurrent changes are occurring across space and time, and CRP is only one of many factors influencing wildlife populations. Trying to isolate and quantify the contribution of CRP to large‐scale population changes under these conditions is extremely difficult and tenuous. Data‐quality issues affecting many large‐scale monitoring programs exacerbate the problem. We use a case study of land‐use and pheasant‐monitoring data in Minnesota from 1974–1997 to illustrate these problems. In our example, roadside counts of Ring‐necked Pheasants (Phasianus colchicus) were correlated positively with percent of CRP grasslands within 1.6 km of survey routes, but the predicted change in mean pheasant counts (pre‐CRP vs. CRP) was negative in three of five regions despite the addition of up to 8% CRP grasslands. We also documented concurrent losses (1.8%–6.1% per year) of alternative reproductive habitats that apparently counteracted the positive association between pheasant counts and CRP abundance. These results illustrate the need for a more comprehensive evaluation of Farm Bill effects on wildlife, including commodity provisions that lead to conversion of pasture, hayland, and small grains to row crops.

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Combining data from state and national monitoring surveys to assess large-scale impacts of agricultural policy

Cited by 6 publications

References 11 publications

Sensitivity Analyses of a Population Projection Model of Ring-Necked Pheasants

Sensitivity Analyses of a Population Projection Model of Ring-Necked Pheasants

Pheasant responses to U.S. cropland conversion programs: A review and recommendations

Using regional wildlife surveys to assess the CRP: scale and data-quality issues

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