Heterogeneous Landscape International Research Experience for - - PowerPoint PPT Presentation

IRES 2016: Exploring Patterns of Biodiversity in Heterogeneous Landscape

International Research Experience for Students

UNIVERSITY OF SWAZILAND

Balancing Biodiversity and Agriculture Is heterogeneity the answer?

Heterogeneity Hypothesis

Low High Biodiversity

What about biodiversity & landscape heterogeneity?

Components of Landscape Heterogeneity

Fahrig et al. 2011

Low Composition Low Configuration High Composition High Configuration High Composition Low Configuration Low Composition High Configuration

Objectives

• 1. Fine or Broad Scale
• 2. Landscape composition or configuration

Testing the landscape heterogeneity hypothesis

Agriculture Riparian/Forest Closed savanna Communal lands Open savanna Water

2 km

Low Composition Low Configuration High Composition Low Configuration High Composition High Configuration

Testing the landscape heterogeneity hypothesis

Agriculture Riparian/Forest Closed savanna Communal lands Open savanna Water

2 km

Low Composition Low Configuration High Composition Low Configuration High Composition High Configuration

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15 Study Sites

Biodiversity sampling across multiple taxonomic groups

500 m 50 m

Vegetation structural heterogeneity

The alternative or complementary hypothesis for explaining patterns of diversity

Tree height & Cover Grass biomass Shrub cover

Landscapes of biodiversity

• Indicators of environmental

disturbance (Cole et al. 2002)

• Respond rapidly to

environmental change (Murphy et al. 1990)

• Correlate strongly with

vertebrate and invertebrate diversity (Pearson and Cassola 1992)

Land Use, Vegetation, and Beetle Diversity:

What are the questions to ask?

https://www.illovosugar.co.za/UserContent/images/News-Articles/Pg26b.png

• Land use types
• Configuration
• Scale
• Average Structure
• Structure Variance
• Scale

Land Use: Vegetation:

Study Methods:

Aerial View

• Beetles sorted by plot

and by morphospecies

• 75 plots, 9 traps per plot
• 4 traps with meat, 5 traps

without

Dun Beetle Trap: Massimiliano Bisceglie and Yen Yi Tan

Total Findings:

1687 beetles representing 43 species were captured 69 of 75 plots had at least 1 beetle Morphospecies 2 was the most common beetle (n = 709) Six species had only 1 beetle, and 23 had under 10 beetles Maximum beetles per plot: 105 Maximum of one species: 89

Results: Land Use Impacts on Species Richness

• Vegetation negligible
• Amount of agriculture

within 2km of the site

Within 2km Within 2km

• Amount of savanna

within 2km of the site Important: Land use types

• Configuration negligible

• No dung in agriculture
• Potential effects from

pesticides

• Inability to move through

large patches of agriculture

• Displays the need for large

reserves, distance from agriculture to maintain biodiversity

Avian Responses to Landscape Heterogeneity

Alison Ke, UC Berkeley

alisonke@berkeley.edu

Why study birds?

• Diverse
• Sensitive to the

environment

• Mobile

White-bellied Sunbird Dark-capped Bulbul Red-faced Mousebird

Does landscape heterogeneity drive bird species diversity?

Prediction: Yes Alternative: Land-use drives bird diversity

Sampling Birds

2755 individuals 83 species

–4 endemic –2 near-endemic

After 320 point counts:

Landscape composition drives diversity

Species Diversity Land Cover Diversity Species Diversity Proportion of Agriculture

Land-use drives diversity

Habitat Heterogeneity Hypothesis

✓

Land-use Hypothesis ✓

Take Home

Effect of agriculture Landscape scale response

Proportion of Agriculture Species Diversity .25

?

Species Response to Heterogeneity at Different Scales

Celine Carneiro IRES 2016

Focal Species

Black-backed Jackal Large-spotted Genet 15 – 20 km2 2 – 5 km2

What scale of heterogeneity is most influential on

• ccurrence?
• Predictions:

1) Landscape-level heterogeneity Jackal presence edge agriculture 2) Fine-scale heterogeneity Genet presence canopy cover and shrub cover

Sampling

• 1 baited camera, 2 unbaited cameras

Results

• 7 out of 15 grids
• 13 out of 75 plots
• 14 out of 15 grids
• 42 out of 75 plots

Black-backed Jackal Large-spotted Genet

5 5.1 5.2 5.3 5.4 5.5 5.6 5.7 5.8

Patch Cohesion Present Absent

0.5 1 1.5 2 2.5 3 3.5

Grass biomass Present Absent

Species respond to heterogeneity at different scales

What does it mean?

Small Mammal Diversity in the Lowveld of Swaziland

University of Florida Savanna Research Center Nicole Jennings

Introduction

Small mammals are useful for studying habitat heterogeneity.

• Important ecological roles
• Indicators of biodiversity
• Highly mobile
• Short generation times

Saccostomus campestris (Pouched Mouse) Gerbilliscus leucogaster (Bush Veld Gerbil)

Questions & Predictions

 How is diversity affected by vegetation structure at the fine scale?  Prediction: grass biomass and shrub cover is most influential  Is diversity affected at the broad scale?  Prediction: different land cover types influence diversity

Steatomys pratensis (Fat mouse)

Methods

• 5 plots per grid
• 20 Sherman traps per plot
• 4 trap nights per grid
• Measurements
• Ear tagging

Summary Statistics

19 11 10 6 4 1 1 2 4 6 8 10 12 14 16 18 20

Number of Individuals Species Name Abundance of Each Species

 Total of 7,200 trap nights  52 individuals captured

 Low sample size

 Drought effects

Results

0.5 1 1.5 2 2.5 3 3.5 500 1000 1500 2000 2500

Species Richness Variation in Canopy Cover Species Richness Change to Variance in Canopy Cover

 Increase in variance of canopy cover  increase in species diversity

Why?

 Species diversity not affected at landscape scale

Take Home Message

 Heterogeneity is an important factor for small mammal diversity

• Why at these scales?

 Low sample size Drought

Grid Level Example

1 = Highest canopy layer diversity ; species diversity 5 = Lowest canopy layer diversity; species diversity

Birds Ants Beetles Carnivores Rodents Fine Broad

Fine scale vs broad scale heterogeneity?

Different taxa respond at different scales

Birds Ants Beetles Carnivores Rodents Comp Config

Landscape compositional vs configurational heterogeneity?

Compositional heterogeneity most influential, but again varied responses

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IRES in the future: 2017 & 2018

IRES 2016

“Put me ahead in accomplishing my goals as an ecologist” “Very educational and amazing experience”

Thank you and Questions?

UNIVERSITY OF SWAZILAND

Enthusiastic field crews! Max & Yinny for photos!