Avian Diversity in a Temperate Tree-based Intercropping System from inception to now (28 years 1995, 2014)

Transcription

1 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

2 Outline of Presentation Disclaimer! Introduction Materials and Methods Results Discussion Conclusions

3 Disclaimer Red- Shouldered Hawk Kestrel Saw-whet Owl Young Great- Horned Owl Al Gordon, 1939

4 Young great horned owls, 1949

5 Introduction Bridget Stutchbury York University, Mississauga, ON

6 Scarlet tanager 6

7 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

8 Wood Thrush L. Elliot Early haying is problematic Birds per route Bobolink Marie Read

9 Wilson s Warbler R. Royse Breeding Overwintering

10 Low Reproductive Success in Forest Fragments Brown-headed cowbird brood parasite

11 Tropical Deforestation Southern Mexico

12 Losing Out In southern Mexico, young Wood Thrush cannot compete for forest-interior territories Living in forest edges or scrub - decreases winter survival

13 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

14 g sunrise sunset Light loggers (geolocators) tells us the timing of sunrise and sunset at the bird s location

15 Spring Migration: 25 Apr : home! Only 13 days from Brazil!! And, only 8 d of actual flight! 24 Apr Apr April 17 Apr 14 Apr 12 Apr 1000 km

16 Migration Routes: Trans-Gulf overwintered in good habitat 29 Apr 3 May return 27Apr 22 Apr 1 Nov 21 Apr 500 km

17 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

18 Winter Habitat and Shade Coffee Traditional Shade Coffee: Agroforestry Moderate/Low Shade Coffee: Sun Coffee:

19 Shade-grown farms boost biodiversity by providing a haven for migratory birds Environmental Research Web, July, 2010

20 Materials and Methods Study Site University of Guelph Agroforestry Research Station 143 o 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

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22 Leave area 2-year old black walnut

23 The University of Guelph Agroforestry Research Station 10 tree species 6 soil types 2 row widths 3 annual crops 4 replications RCBD 8 years

24 11 years

25 13 years

26 Short Rotation Willow (25,000 stems ha-1) 20 years

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28 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

29 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

30 a b c d e

31 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

32 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

33 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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35 For those of you who routinely read your old N.A. Agroforestry Conference Proceedings: Williams, P. A., H. Koblents and A. M. Gordon 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

36 Site Individuals Species Individuals Species Intercropping Old Field Monocrop Willow Old Growth Total

37 23 years

38 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

39 Number of Species Species Richness

40 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

41 Red-tailed hawk Moles, mice and voles in leave area

42 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

43 Conservation Value Conservation Value

44 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

45 Species found in intercropped field 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.

46 Species Unique to 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.

47 Species New in 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.

48 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

49 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

50 Literature Cited Nuttle, T., A. Leidolf, L.W. Burger, Jr., and B. Loiselle Assessing conservation value of bird communities with Partners in Flightbased ranks. The Auk 120: Ralph, C.J., S. Droege, and J.R. Sauer 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 Recommendations for an international standard for a mapping method in bird census work. Aud. Field Notes 24: Saunders, S Birds: the farmer s friends. OAC Review 21: Small, E The new Noah s Ark: beautiful and useful species only. Part 1. Biodiversity conservation issues and priorities. Biodiversity 12:

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52 Diversity Shannon-Wiener Diversity

53 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

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