Table/Figure – Pesticides Research No. 127 2009 – Buffer zones for biodiversity of plants and arthropods: is there a compromise on width?

Buffer zones for biodiversity of plants and arthropods: is there a compromise on width?

Table 3.18. Summary of the analyses of covariance of Lepidoptera and Bombus in relation to flower and host plant abundance in period 3.

Order/
Family

Genus

Test results F_(ndf,ddf)^P¹ of fixed effects

Test results F_(ndf,ddf)^P¹ of covariates

Field²

Dist.³

Buffer⁴

Buffer×
Distance⁵

Temp.⁶

Day⁷

Tid(day)⁸

Tid×tid(day)⁹

Flowers in ¹⁰
hedge-bottom

Flow. hedge-b.× Flow. hedge-b.¹¹

Flowers
in field¹²

Host plants¹³

Host plants×
host plants¹¹

Lepidoptera

Pieris

4.12_{(3, 18.09)}^*

34.18_{(3, 14.28)}^***

11.43_{(4, 26.42)}^***

2.41_{(12, 45.74)}^*

16.76_{(1, 264.6)}^***

7.10_{(4, 259.2)}^***

10.81_{(4, 259.2)}^***

11.82_{(1, 14.44)}^**

3.18_{(1, 38.69)}^(P=0.08)

2.15_{(1, 36.31)}^NS

Apidae

Bombus

0.53_{(3, 3.231)}^NS

30.49_{(1, 3.149)}^*

1.77_{(4, 24.40)}^NS

2.57_{(4, 25.27)}^(P=0.06)

2.28_{(3, 137)}^(P=0.08)

4.72_{(4, 137)}^**

10.93_{(1, 9.89)}^**

4.05_{(1, 9.215)}^(P=0.07)

3.71_{(1, 8.09)}^(P=0.09)

¹^NSnot significant, ^*P < 0.05, ^**P < 0.01, ^***P < 0.001. F is the F-value, ndf and ddf is the numerator and denominator degree of freedom used for testing the significance.

²Effect of field (four fields were included in the experiment).

³ Effect of distance from field edge (sampling was carried out 0, 2, 5, 9 and 18 m from the field edge). For Bombus the distances 2 and 5 m only could be included in the analysis due to very few observations further away from the field edge.

⁴Effect of buffer width (0, 4, 6, 12 and 24 m).

⁵Effect of the combination of distance and buffer width (in total there were 4×5=20 combinations for Lepidoptera and 2×5=10 combinations for Bombus).

⁶ Effect of temperature (°C, mean temperature of the time interval of transect walks).

⁷Test for effect of sampling day (day was numbered relative to 1 July).

⁸Test for effect of sampling time within sampling days. (time was measured as hours after 12:00 (time before noon were negative).

⁹ Test for non-linear effect of sampling time within sampling days.

¹⁰The average number of thistle flowers (Cirsium spp. and Carduus spp.).

¹¹ Test for non-linear effect.

¹² The average number of flowers (All flowers).

¹³ The effect of host plants for Pieris butterflies (ground-cover ratio of the plants Brassica).