Ecological Archives E096-173-A1

Sarah L. Amundrud and Diane S. Srivastava. 2015. Drought sensitivity predicts habitat size sensitivity in an aquatic ecosystem. Ecology 96:16671675. http://dx.doi.org/10.1890/14-1828.1

Appendix A. The size distribution of surveyed bromeliads in relation to insect occurrences.

Table A1. Frequency of occurrence, body size, and habitat size components for bromeliad insect larvae. FG represents functional group (P: predator; D: detritivore; F: filter feeder); abd represents total abundance over all surveyed bromeliads; mass (mg) represents maximum dry mass of insect larvae. meanobs represents observed mean bromeliad size of occurrence; meannull represents mean bromeliad size of occurrence expected from random species assembly; SDnull represents standard deviation of expected mean bromeliad size obtained from randomization (resampled 10,000 x). From these three components, we calculated habitat size sensitivity indices (Z) and their associated p values (p).

Bromeliad insect larvae

Habitat size of occurrence

Taxon

FG

abd

mass (mg)

meanobs

meannull

SDnull

Z

p

Mecistogaster modesta

P

121

12.29

476.39

370.67

18.37

5.75

<0.001

Tanypodinae

P

221

0.04

360.82

350.14

12.49

0.86

0.392

Ceratopogonidae

P

184

0.04

358.08

356.01

14.06

0.15

0.883

Tipulidae

D

1529

5.50

315.12

314.53

4.31

0.14

0.891

Scirtidae

D

4627

1.07

314.42

308.87

2.57

2.15

0.031

Polypedilum sp.

D

4579

0.04

338.72

308.91

2.61

11.41

<0.001

Orthocladiinae

D

1382

0.03

319.28

315.39

4.49

0.87

0.386

Anopheles spp.

F

152

1.29

346.23

362.51

15.8

-1.03

0.303

Culex spp.

F

188

0.48

458.11

355.30

14.04

7.32

<0.001

Wyeomyia spp.

F

377

1.29

279.38

335.61

8.92

-6.30

<0.001

 

FigA1

Fig. A1. Natural and surveyed size distribution of forest bromeliads. Gray histogram represents density of randomly sampled forest bromeliads (> 15 cm in diameter) per hectare obtained from data originally published in Melnychuk and Srivastava (2002). These bromeliads have a mean water holding capacity of 65.55 mL (± 54.96 SD, n = 215), and were sampled over an area of 1984.5 m². Black histogram represents density of bromeliads from the survey in the current study. These bromeliads have a mean water holding capacity of 305.20 mL (± 286.61 SD, n = 68). Bars of black histogram are slim to improve clarity. * indicates that the natural density in this size class was greater than zero but less than 5/ha, the detection limit of the bromeliad survey in Melnychuk and Srivastava (2002). Note that frequency is on a log-scale.


 

Literature cited

Melnychuk, M. C., and D. S. Srivastava. 2002. Abundance and vertical distribution of a bromeliad-dwelling zygopteran larva, Mecistogaster modesta, in a Costa Rican rainforest (Odonata: Pseudostigmatidae). International Journal of Odonatology 5:81–97.


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