Supporting information

1

Supporting information

2 3

Table S1. Details of the abbreviation used of field sites and the sampling dates

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Numbers, names and codes of the field sites in the Yucatan Peninsula at which bees were

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collected, with sampling date. Sites in which the pollination experiment was performed are

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highlighted using a pink background. Site numbers and codes correspond to those in Figures 1,

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S3 and S8. Site number

Sites names

Sites codes

Sampling date

1 Cepeda

Cepeda(2010)

2 Muna

Muna(2011)

22/Jul/2011

3 Tebek

Tebek(2010)

4/May/2010

4 Homun

Homun(2011)

28/Jun/2011

5 Toh

Toh(2010)

6 Motul

Motul(2010)

10/Jun/2010

7 Yobain

Yobain(2010)

11/Jun/2010

8 Buctzots

Buctzots(2011)

29/Jul/2011

9 TiziminA

TiziminA(2010)

30/May/2010

10 Tekal de Venegas A

TeVe(2011)

21/May/2011

11 Tekal de Venegas B

TeVeB(2010)

12 Moctezuma

Moctezuma(2011)

13 Rancho Alegre

RaAl(2011)

1/Jun/2011

14 Tizimin D (Santa Maria

TiziminD(2010)

5/Jun/2010

15 Tizimincen C

TiziminC(2010)

3/Jun/2010

16 TiziminB

TiziminB(2010)

1/Jun/2010

17 San Pedro Bacab

SPB(2011)

18 Tixcaltuyub

Tixcaltuyub(2011)

24/Jun/2011

19 Santa María

StaMaria(2011)

26/Jun/2011

20 Nenela C

NenelaC(2011)

14/Jun/2011

21 Timul A

TimulA(2011)

09/Jun/2011

22 Xaya

Xaya(2011)

5/Aug/2011

23 Tixmehuac

Tixmehuac(2011)

15/Jun/2011

24 Nenela A

NenelaA(2011)

9/May/2011

25 TahDziu B

TaDB(2011)

18/Jun/2011

1

19-20/May/2010

8-9/May/2010

15/Jun/2010 30/May/2011

31/May/2011

26 TahDziu A

TaDA(2011)

27 Ichmul

Ichmul(2010)

31/May/2010

28 Tekax A

TekaxA(2010)

2/May/2010

29 Tixcuytun A

TixcuytunA(2011)

30 Tekax B

TekaxB(2010)

31 Tixcuytun B

TixcuytunB(2011)

17/Jun/2011

32 Tixcuytun C

TixcuytunC(2011)

22/Jun/2011

33 Alfonso Caso

AC(2011)

34 Tzucabab C

TzucababC(2010)

9/Jun/-2010

35 Tzucabab B

TzucababB(2010)

24/May/2010

36 Yaxcopil

Yaxcopil(2011)

37 Becanchen

Becanchen(2010)

8 9

2

6/Jun/2011

7/Jun/2011 12-13/May/2010

13/May/2011

1/Aug/2011 8/Jun/2010

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Table S2. Relationships between land cover and the bee communities across sites.

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Spearman rank correlation coefficients of the relationship between either total bee abundance

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or bee species richness (combined pan trap and transect walk data) and land cover at different

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spatial scales from a site’s centre. Land cover is the proportion of land covered by:

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agricultural fallow land, home gardens and pasture (FGP); primary or secondary growth

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forest (Forest); cropland (Crops), comprising staples (maize, beans), cash crops (e.g. chilli)

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and orchards; and an overall index of the diversity of land cover (Lc-diversity) of all three

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land cover classes: FGP, Forest and Crops. The largest absolute correlation coefficient

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(positive or negative) of a row is given in bold.

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FGP Distance Abundance Richness (Chao-1)

200 0.04 -0.31

Distance class from the centre of a site (in m) 300 400 500 600 700 800 0.09 0.11 0.09 0.07 0.06 0.11 -0.28 -0.27 -0.28 -0.30 -0.31 -0.32

900 0.05 -0.32

1000 0.06 -0.30

900 0.03 0.21

1000 0.04 0.18

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Forest Distance Abundance Richness (Chao-1)

200 -0.25 0.05

Distance class from the centre of a site (in m) 300 400 500 600 700 800 -0.20 -0.13 -0.06 -0.01 0.03 -0.26 0.12 0.16 0.19 0.21 0.22 0.23

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Crop Distance Abundance Richness (Chao-1)

200 0.13 0.22

Distance class from the centre of a site (in m) 300 400 500 600 700 800 0.06 0.04 0.02 0.02 0.01 0.16 0.17 0.15 0.07 0.02 0.02 0.28

900 -0.01 0.01

1000 -0.02 0.03

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Lc-diversity Index Distance

200

300

400

500

600

700

800

900

1000

Abundance

-0.18

-0.32

-0.11

-0.03

0.04

0.06

0.06

0.03

0.04

0.03

0.20

0.15

0.19

0.20

0.20

0.19

0.20

0.20

Richness (Chao-1)

Distance class from the centre of a site (in m)

23

3

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Table S3. Relationships among land cover variables across sites.

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Relationships among different classes of land cover in the landscape: agricultural fallow land,

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home gardens and pasture (FGP); primary or secondary growth forest (Forest); cropland

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(Crops), comprising staples (maize, beans), cash crops (e.g. chilli) and orchards; and an

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overall index of the diversity of land cover (Lc-diversity). In the lower left diagonal of the

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box, correlation coefficients are shown (significant coefficients are in bold) and, in the upper

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right diagonal, the corresponding significance (probability) after correction for multiple

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comparisons using the False Discovery Rate (FDR) approach (Holm 1979; Fox 2005).

32 33

Lc-

FGP

Forest

Crops

-

0.01

0.41

0.51

Forest

-0.69

-

0.34

0.98

Crop

-0.21

-0.16

-

0.01

-0.14

0.01

0.75

-

FGP

Lc-diversity Index

diversity

34 35

4

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Table S4. Statistical fit of the models of pollination success in relation to bee

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communities and land use across sites.

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Statistical fit of models relating pollination of chilli to bee communities and surrounding land

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use at 11 sites; 1) combined data (abundance and species richness of bees from pan traps and

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transect walks), 2) abundance and species richness of bees from transect walk data only, 3)

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abundance and species richness of bees from pan trap data only and 4) abundance of

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Lasioglossum sp. 1 and species richness of bees from all data (from pan traps and transect

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walks) combined. Model fit was evaluated using SEM (structural equation models) in AMOS

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v. 7.0 (Arbuckle 2006). Within each model we present the saturated model (with all possible

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hypothesized links, in which there are as many parameters estimated as degrees of freedom),

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and the second best fit model that corresponds to the Forest landscape variable in 1) and 2),

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Forest and FGP in 3) and FGP in 4), as well as, the independence (null) model, which

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assumes zero population covariance among the observed variables. For each of the three

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models, three fit indices are provided: the Akaike Information Criterion (AIC), the Root Mean

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Square Error of Approximation (RMSEA) and a Chi-square test (χ2). AIC†

RMSEA‡ χ2 (P value)§

1) Model using abundance of bees from combined data Independence (null) model

257.12

1.14

0.00

Best fit model FGP

256.24

0.00

0.54

Best fit model Forest

254.02

0.00

0.58

20.00

2.14

0.02

Saturated model

2) Model using bee abundance from transect walks Independence (null) model

257.41

1.23

0.00

Best fit model FGP

249.95

0.27

0.12


250.00

0.40

0.04

42.00

0.00

0.08

Saturated model

3) Model using bee abundance from pan traps Independence (null) model

252.27

1.30

0.00

Best fit model FGP

248.97

0.00

0.66


248.97

0.00

0.60

42.00

0.00

0.08

Saturated model

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4) Model using Lasioglossum sp. 1 abundance from combined data Independence (null) model

261.85

1.25

0.02

Best fit model FGP

249.90

0.00

0.72


251.52

0.00

0.70

42.00

0.00

0.02

Saturated model 51 52

† Lower AIC values indicate better fit;

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‡ RMSEA 5%) and widespread (>10 sites) and were used in

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further statistical analysis.

63 64

10

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Table S6. Canonical Correspondence Analysis of the relationships between bee

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communities and land use across sites.

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Results of the Canonical Correspondence Analysis (CCA) presented in Fig. S2 (supporting

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information), showing the percentage of variation explained by analysis of the relationships

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between bee diversity and three land use variables: agricultural fallow land, home gardens and

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pasture (FGP); primary or secondary growth forest (Forest); and crops (Crops). Inertia is a

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mean squared coefficient, which represents the total variability in species abundance with

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respect to the land use variables. Proportion represents the proportion of the variation explained

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by the data, calculated by subjecting the inertia matrix (variation of the species abundance with

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respect to the environment) to weighted regression. The constrained values represent the

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percentage of variation explained by the axes (i.e. environmental variables), in this case 14%.

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Here 100% represents over-fitting of the analysis and 0% represents poor explanation of the

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variation. However, an analysis with low constrained values still provides important

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information about the axes analyzed. ‘Unconstrained’ is the proportion of variation that has not

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been explained by the axes (i.e. environmental variables), in this case 86%. The final

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permutation test shows that the only variable that significantly explains the distribution of bee

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species is FGP.

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Inertia

Proportion

Rank

Total

6.04

1.00

Constrained

0.86

0.14

4.00

Unconstrained

5.18

0.87

32.00

Percentage of variation explained by the constrained axes. Eigenvalues for constrained axes: CCA1

CCA2

0.34

0.27

CCA3

CCA4

0.16

0.09

Eigenvalues for unconstrained axes: CA1

CA2

CA3

CA4

CA5

CA6

CA7

CA8

0.60

0.51

0.47

0.41

0.33

0.32

0.29

0.27

(we show only 8 of all 32 unconstrained eigenvalues) Permutation test for CCA under reduced model

FGP

DF

AIC

F

Pr(>F)

1

220.18

1.68

0.015 *

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Lc-diversity

1

220.22

1.64

0.075 .

Forest

1

220.28

1.58

0.095 .

Crops

1

220.54

1.32

0.255

Significance code: ‘*’ P0.40

Significant, but not after correction by FDR

rs>0.20

Non-significant, weak correlation

** = P|t|36 DF)

Abundance (total)~ Crops

Poisson

-0.13

0.03

-1.59

0.11

FGP

Poisson

0.10

0.02

1.19

0.23

Forest

Poisson

0.43

0.03

5.54