Avian Diversity in a Temperate Tree-based Intercropping System from inception to now (28 years 1995, 2014) North American Agroforesty Conference, Ames, Iowa, June, 2015 Sophie Gibbs 1, Hanita Koblents 2, Andrew M. Gordon 1,4, Naresh V. Thevathasan 1 and Peter A. Williams 3 1 School of Environmental Sciences, University of Guelph, Guelph, ON, Canada, N1G 2W1 2 City of Halifax, Halifax, NS, Canada, B3J 3A5 3 Williams and Associates, Rockwood, ON, Canada, N0B 2K0 4 Author for correspondence
Outline of Presentation Disclaimer! Introduction Materials and Methods Results Discussion Conclusions
Disclaimer Red- Shouldered Hawk Kestrel Saw-whet Owl Young Great- Horned Owl Al Gordon, 1939
Young great horned owls, 1949
Introduction Bridget Stutchbury York University, Mississauga, ON
Scarlet tanager 6
Disappearing Songbirds R. Royse Cerulean Warbler Marie Read Eastern Kingbird R. Royse Canada Warbler Marie Read Rose-breasted Grosbeak Lang Elliot Dickcissel Marie Read Painted Bunting
Wood Thrush 1965 1975 1985 1995 2005 L. Elliot Early haying is problematic Birds per route 7 6 5 4 3 2 Bobolink 1 0 1965 1965 1975 1985 1995 2005 Marie Read
Wilson s Warbler R. Royse Breeding Overwintering
Low Reproductive Success in Forest Fragments Brown-headed cowbird brood parasite
Tropical Deforestation 1967 1990 Southern Mexico
Losing Out In southern Mexico, young Wood Thrush cannot compete for forest-interior territories Living in forest edges or scrub - decreases winter survival
Losing Out In Jamaica young American Redstarts are forced into dry scrub, where there is little food In Mexico most young Hooded Warblers live as desperate floaters because there is not enough forest
2006 1.5g sunrise sunset Light loggers (geolocators) tells us the timing of sunrise and sunset at the bird s location
Spring Migration: 25 Apr : home! Only 13 days from Brazil!! And, only 8 d of actual flight! 24 Apr 21-23 Apr 18-20 April 17 Apr 14 Apr 12 Apr 1000 km
Migration Routes: Trans-Gulf overwintered in good habitat 29 Apr 3 May return 27Apr 22 Apr 1 Nov 21 Apr 500 km
Migration Routes: Round-Gulf overwintered in bad habitat 20 May 26 May return May 26 compare to May 3 18 May 19 May 28 Apr 1 May 30 Oct 27 Apr
Winter Habitat and Shade Coffee Traditional Shade Coffee: Agroforestry Moderate/Low Shade Coffee: Sun Coffee:
Shade-grown farms boost biodiversity by providing a haven for migratory birds Environmental Research Web, July, 2010
Materials and Methods Study Site University of Guelph Agroforestry Research Station 143 o 43 28 N Latitude, 80 o`12 32 W Longitude Established 1987, 30 ha Row spacing 12.5 m, 15 m Annual crops corn, bean, wheat, (willow) Tree species silver maple, white ash, hazelnut, white cedar, hybrid poplar, red oak, black locust, black walnut, Norway spruce Tree age (2015) 30 years
Leave area 2-year old black walnut
The University of Guelph Agroforestry Research Station 10 tree species 6 soil types 2 row widths 3 annual crops 4 replications RCBD 8 years
11 years
13 years
Short Rotation Willow (25,000 stems ha-1) 20 years
1995 Monitored sites - tree-based intercropping (30 ha) (with and without nesting boxes) - old field (10 ha) - monocropped corn (24 ha) Variable 80 m by 80 m square quadrats established Spot-mapping method (Robbins, 1970) Birds monitored mid-may to mid-july, 6:30-9:30 am Evidence of nesting noted
2014 Monitored sites - tree-based intercropping (30 ha) - old field (10 ha) - monocropped soybean (27 ha) - short rotation willow (17 ha) - old-growth hardwood forest (6ha) Point-count surveys - fixed location, within a 100 m radius Variable point count stations - minimum of 250 m between Birds monitored May July, 6:30-10:30
a b c d e
Shannon-Weiner Diversity Index (H ) where p i is the proportion of each species in the total species abundance (addresses both evenness, richness) Conservation Value Index (Nuttle et al., 2003) where s is the species richness, a i is the abundance and w i is the weighting factor species specific score determined by Partners in Flight, an international NGO
Differences in Methods 1995 to 2014 Square plots (1995) as opposed to circular plots Continuous rotation as opposed to a fixed number (3), therefore more surveys per plot (1995) Total area of plots was ~ 1/5 as much in 1995 Time spent surveying per unit area was similar in both 1995 and 2014
Results and Discussion 1995 (8 years after inception) Breeding birds: old field > intercropped > mono Foraging birds: intercropped > old field > mono Provision of nesting boxes in intercropped field allowed tree swallows and bluebirds to nest there
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For those of you who routinely read your old N.A. Agroforestry Conference Proceedings: Williams, P. A., H. Koblents and A. M. Gordon. 1995. Bird use of an intercropped corn and old field in southern Ontario, Canada. Proc. 4 th North American Agroforestry Conf., July 23-28, 1995, Boise, Idaho. p. 158-162.
1995 2014 Site Individuals Species Individuals Species Intercropping 285 17 182 32 Old Field 70 7 174 27 Monocrop 8 4 142 23 Willow 56 15 Old Growth 48 21 Total 363 18 606 49
23 years
Increase in insect, bird and mammal populations compared to conventional agriculture Bird nests in willow plantations Beneficial insects feed on aphids Photos: R.Cardinael, Guelph, ON, 2009
Number of Species Species Richness 40 35 30 25 20 15 10 2014 1995 5 0
Species richness higher in 2014 than 1995 TBI site has grown Snags support woodpeckers Vertical structure supports raptors Old field site has grown Early and mid-successional habitat (chestnut-sided warbler, house wren) Monocropped soy: hedgerows, buildings, woodlot
Red-tailed hawk Moles, mice and voles in leave area
Conservation Value of a bird community depends on value judgement (Small et al., 2003) e.g. species-at-risk >> species of no concern e.g. non-native species << native species
Conservation Value Conservation Value 12 10 8 6 4 2014 1995 2 0
2014 sites similar, 1995 sites similar 1995 sites > 2014 sites?? Previously abundant species are now in decline e.g. old field sites: Bobolink, Eastern meadowlark
Species found in intercropped field 1995 2014 Savannah sparrow Chipping sparrow Song sparrow Indigo bunting Red-winged blackbird Tree swallow Horned Lark Eastern bluebird Killdeer Eastern kingbird Eastern meadowlark American robin Canada goose American crow Mourning dove American goldfinch European starling Red-tailed hawk Downy woodpecker Eastern phoebe Tree swallow American crow Black-capped chickadee Grey catbird Cedar waxwing Warbling vireo American redstart Common grackle European starling American goldfinch Song sparrow Savannah sparrow Eastern bluebird Northern flicker Least flycatcher Eastern wood peewee Northern rough-winged swallow Bluejay House wren American robin Red-eyed vireo Yellow warbler Red-winged blackbird Baltimore oriole Northern cardinal Indigo bunting Chipping sparrow Field sparrow Passerine spp.
Species Unique to 1995 1995 2014 Savannah sparrow Chipping sparrow Song sparrow Indigo bunting Red-winged blackbird Tree swallow Horned Lark Eastern bluebird Killdeer Eastern kingbird Eastern meadowlark American robin Canada goose American crow Mourning dove American goldfinch European starling Red-tailed hawk Downy woodpecker Eastern phoebe Tree swallow American crow Black-capped chickadee Grey catbird Cedar waxwing Warbling vireo American redstart Common grackle European starling American goldfinch Song sparrow Savannah sparrow Eastern bluebird Northern flicker Least flycatcher Eastern wood peewee Northern rough-winged swallow Bluejay House wren American robin Red-eyed vireo Yellow warbler Red-winged blackbird Baltimore oriole Northern cardinal Indigo bunting Chipping sparrow Field sparrow Passerine spp.
Species New in 2014 1995 2014 Savannah sparrow Chipping sparrow Song sparrow Indigo bunting Red-winged blackbird Tree swallow Horned Lark Eastern bluebird Killdeer Eastern kingbird Eastern meadowlark American robin Canada goose American crow Mourning dove American goldfinch European starling Red-tailed hawk Downy woodpecker Eastern phoebe Tree swallow American crow Black-capped chickadee Grey catbird Cedar waxwing Warbling vireo American redstart Common grackle European starling American goldfinch Song sparrow Savannah sparrow Eastern bluebird Northern flicker Least flycatcher Eastern wood peewee Northern rough-winged swallow Bluejay House wren American robin Red-eyed vireo Yellow warbler Red-winged blackbird Baltimore oriole Northern cardinal Indigo bunting Chipping sparrow Field sparrow Passerine spp.
Conclusions Adding a third dimension to a monocropped agroecosystem via trees provides habitat and food for birds leading to increased avian presence and diversity Intercropping at latitudes that correspond to the summer ranges of songbirds may be beneficial Modified tree architecture? e.g. Kirtland s warbler
Saunders (1909) Ontario Agricultural College Review, advised the farmer: set aside a prepared shrubbery for the breeders and create cavities for nesting to take full advantage of the benefits that the avian community can bring to agriculture
Literature Cited Nuttle, T., A. Leidolf, L.W. Burger, Jr., and B. Loiselle. 2003. Assessing conservation value of bird communities with Partners in Flightbased ranks. The Auk 120:541 549. Ralph, C.J., S. Droege, and J.R. Sauer. 1995. Managing and monitoring birds using point counts: standards and applications. U.S.D.A. For. Serv. Gen. Tech. Rept. PSW-GTR-149. Robbins, C. S. 1970. Recommendations for an international standard for a mapping method in bird census work. Aud. Field Notes 24:448-450. Saunders, S. 1909. Birds: the farmer s friends. OAC Review 21:723-726. Small, E. 2011. The new Noah s Ark: beautiful and useful species only. Part 1. Biodiversity conservation issues and priorities. Biodiversity 12:232 247.
Diversity Shannon-Wiener Diversity 3.5 3 2.5 2 1.5 1 2014 1995 0.5 0
Diversity generally lower in 1995 than 2014 Little difference between sites in 2014 All sites more similar in health than species richness would lead you to believe Willow field largest monocropped area with vertical structure, but no hedgerows