Agricultural biodiversity and associated services across rural-urban landscapes - field studies

A. Wenzel, I. Grass, T. Tscharntke

B01

Methodology1. Thirty-six farm sites

across two rural-urban

transects

a) Pollination studies on

important crops (lablab,

cucumber, chili)

b) Bird studies in dry and

rainy season

2. Pan-trapping of bees in

147 farm households of

the socioeconomic

survey

3. 30 lablab fields across

Bangalore for further

pollination studies

Phase I conclusions

Pollinator diversity along the rural-urban interface is threatened by high agrochemical input

Seasonality and farming decisions cause spatiotemporal dynamics in pollinator diversity and

pollination services that require more study

Ecosystem services provided by birds are possibly endangered by urbanization

ResultsPollination studies

Systematic review of 157 peer-reviewed articles:

major research deficit in crop pollination

in (sub)tropical cities under transition

Pollination enhances fruit and seed set

of lablab by 6.1% and 29.5%, respectively

Flower visitation to lablab not affected

by amount of impervious surface

High amounts of build-up may not

necessarily disrupt pollination services

Socioeconomic-ecological studies

Reduced bee abundance on farms

with high usage of agricultural inputs

Bird studies

Bird diversity decreases with urbanization

Functional shifts with urbanization

IntroductionWe investigated agricultural biodiversity and its potential to

provide local agriculture with the important ecosystem

services crop pollination and biological pest control along

rural-urban gradients.

CollaborationsA01 & A02: Intensification effects on crop production

B01 - modelling: Spatial simulation models of bee dynamics

C01 & C02: Landscape analyses, crop identity and upscaling

C03, C05 & B02: Socioeconomic-ecological studies

I-B01.1 & I-B01.2: Plant and insect diversity in Bangalore

Fig. 1: Variation in (a+b) bee abundance on agricultural fields of

147 households and (c+d) in bird diversity on 36 farm sites with

amount of impervious area in 500 m radius and number of local

agricultural inputs. Predictions at p < 0.05 are shown with 95% CI.

Fig. 2: Shifts in the functional composition of bird communities

across urbanization stages (CWM = community weighted mean).