# Presentation: 829985

## Effects of fire, extreme weather, and anthropogenic disturbance on avian biodiversity in the United States

**Anna M. Pidgeon1, Chad Rittenhouse1, Thomas Albright1,****Volker C. Radeloff1, Curtis H. Flather2, Jeffrey G. Masek3****Roger B. Hammer4, Murray K. Clayton5, and Susan I. Stewart6**
- 1Department of Forest Ecology and Management, University of Wisconsin-Madison, Wisconsin 2U.S.Forest Service Rocky Mountain Research Station, Fort Collins, Colorado 3NASA Goddard Flight Center, Greenbelt, Maryland 4Department of Sociology, Oregon State University, Corvallis, Oregon
- 5Department of Statistics, University of Wisconsin-Madison, Madison, Wisconsin6U.S.Forest Service Northern Research Station, Evanston, Illinois

## Introduction

- Biodiversity can change substantially within one decade with no obvious pattern of increase or decrease
- How much doeslocal disturbanceaffect biodiversity?

**North American Breeding Bird Survey**

**Avian species richness change 1990 – 2000**

## Objectives

**Our overarching goal is to measure and predict the effects of disturbance on avian biodiversity***** ***
- Objectives:
- Understand the effects of extreme weather (i.e., hurricanes and tornadoes, heat waves, and droughts), on avian biodiversity;
- Understand the effects of fire on avian biodiversity
- Understand the effects of human disturbance (i.e., specifically clearcuts, fragmentation) on avian biodiversity; and
- Test hypotheses regarding the effects of disturbance on bird species richness, similarity, and the abundance of selected common and rare species.

## Remote sensing data

## Remote sensing data

## Year 1 focus: Hurricanes and Drought

- Hurricanes
- cause substantial changes in local forest vegetation and thus bird habitat
- forecast to increase with sea surface warming
- regional scale effects on avian biodiversity unclear

**Notes:**
in the southern or eastern US, on average at least 1 major hurricane (defined as Cat 3 or higher) makes landfall each year and 15 have since 1995.  Hurricanes may have direct effects on avian populations via mortality as well as indirect effects through alteration of vegetation, which may affect avian species diversity at local scales.  However, it is not clear whether those effects are evident at regional scales as well. [Transition to next slide] We ask two questions: 1) Does bird species diversity change in areas affected by hurricanes compared to unaffected areas?  And 2) Is the change in diversity consistent among species and regions? 

## Hurricanes

- Does bird species richness change in areas affected by hurricanes?
- Are changes consistent
-      among guilds?

**Notes:**
We ask two questions: 1) 2).  For data on bird species richness we used the north american bbs.  BBS survey routes are shown here.  Birds are surveyed on these routes once eacd year by a comptetent volunteer.  They are aout 40 km long, and a total of 50, 3 minute counts are conducted.  

## Breeding Bird Guilds

- Habitat type
- Shrubland
- Woodland
- Nest location
- On or near ground
- Midstory or canopy

- Nest type
- Cavity
- Open cup
- Migratory status
- Resident
- Short distance
- Neotropical migrant

**Notes:**
Define guilds. BE SURE TO STATE OUR EXPECTATION: “WE EXPECTED SHRUBLAND RICHNESS WOULD INCREASE DUE TO THE CANOPY-OPENING EFFECTS OF HURRICANES IN FORESTED AREAS”

## Landsat Time Series

-  Annual or** **biennial images
-   from 1984 – 2005
-  Data from North American  Forest Dynamics Project
-  Selected 5 scenes with  major hurricane events

**Notes:**
Change figure to be the 5 focal scenes, 2 in Gulf, 3 on East Coast.  Explain the LTSS and how disturbance was obtained.

We looked for routes that had experienced hurricanes either near or intersecting the route, and for which there existed a LTSS.  .  

## d1

*d**1*

*d**2*

**Notes:**
For each BBS route, we calculated the distance from the route center to the hurricane center path, the distance from the route center to the coast.  We also calculated the proportion of each land cover class, and the mean and std. deviation of NDVI within a 19.7 km radius of the route center for each year/image in the LTSS

## Disturbed Forest

-         -5      -4       -3       -2      -1      +1     +2      +3      +4      +5

**Notes:**
Explain model showing that period (time), distance to hurricane, were significant predictors of the amount of disturbance within each scene. State that we used period as a proxy for disturbance so we could specifically look for a hurricane effect above and beyond the background disturbance.

## Woodland Guild

| Effect | Estimate ± SE | Pr > F |
| --- | --- | --- |
| Intercept
Period
Distance to Hurricane
Log(avgNDVI)
Log(stdNDVI)
Proportion Forest | 160.91 ± 55.15

0.088 ± 0.028
23.52 ± 6.19
-61.56 ± 20.07
24.11 ± 4.88 | 
0.0704
0.0029
0.0002
0.0028
<.0001 |

## Mean Richness of Woodland Guild

-         -5       -4       -3       -2       -1       +1      +2      +3      +4      +5

**Notes:**
We expected Woodland Guild species richness would decrease following a hurricane due to loss of forest structure.  Instead, we found no discernable pattern posthurricane.

## Species Nesting On or Near the Ground

| Effect | Estimate ± SE | Pr > F |
| --- | --- | --- |
| Intercept
Period
Distance to Hurricane
Log(avgNDVI)
Log(stdNDVI)
Proportion NonForest
Proportion Forest
Proportion Water | 88.48 ± 38.67

0.037 ± 0.014
14.22 ± 4.99
-28.60 ± 11.53
25.14 ± 7.62
32.48 ± 8.43
18.63 ± 8.97 | 
0.0012
0.0096
0.0053
0.0148
0.0022
0.0004
0.0448 |

## Species Nesting On or Near the Ground

-         -5       -4       -3       -2       -1       +1      +2      +3      +4      +5

**Notes:**
We expected richness for species nesting on or near the ground to increase following a hurricane due to the increase in vegetation structure and productivity following forest canopy disturbance.  We found that richness was initially high 5 years before a hurricane, but lower and stable for all remaining periods.

##  Period (i.e. Hurricane) Effect for 4 of 9 Guilds

- Habitat type
- Shrubland
- Woodland
- Nest location
- On or near ground
- Midstory or canopy

- Nest type
- Cavity
- Open cup
- Migratory status
- Resident
- Short distance
- Neotropical migrant

## Conclusions – Hurricanes 

- Hurricane effects were statistically significant, but only when accounting for forest cover, and other habitat variables
- However, ***regional*** effects on avian richness were less than expected, and short in duration

## Year 1 focus: Hurricanes and Drought

- Droughts
- temporally and spatially diffuse
- frequency and severity may increase with climate change
- effect on birds not well understood

**Notes:**
in the southern or eastern US, on average at least 1 major hurricane (defined as Cat 3 or higher) makes landfall each year and 15 have since 1995.  Hurricanes may have direct effects on avian populations via mortality as well as indirect effects through alteration of vegetation, which may affect avian species diversity at local scales.  However, it is not clear whether those effects are evident at regional scales as well. [Transition to next slide] We ask two questions: 1) Does bird species diversity change in areas affected by hurricanes compared to unaffected areas?  And 2) Is the change in diversity consistent among species and regions? 

## Questions

- What indicator of the avian community is most responsive to drought?
- Which habitat and migratory guilds are most affected by drought?

## Drought metrics

**Standardized Precipitation Index (“rainfall”)**
- Interpolated from met. stations
- For specific time period & scale
- Scaled in terms of standard deviations from averages
**Standardized seasonal greenness (“greenness”)**
- Integrated growing season greenness from AVHRR NDVI
- Scaled in terms of standard deviations from averages

## rainfall

**Notes:**
Change drought.metric, SPI, and add white space on right side (move to left).

## Avian abundance most correlated with rainfall

- Similarity

**Notes:**
Double check why n changes.  Answ.  I think it is a typo on this figure.

## Grassland and water guilds most correlated with rainfall

## Neotropical migrants and residents are  correlated with greenness

**Notes:**
As greenness changes from year to year the birds respond to it right away

## Conclusions – Drought 

- Full year rainfall and greenness deviations were the most relevant measure of drought for birds
- Abundance more sensitive than richness or community similarity
- Water and grassland guild most related to rainfall deviations
- Among migratory guilds, resident species may be more robust to lower than average greenness.

## Conclusions – Overall 

- We need a better understanding of disturbance effects on biodiversity
- Extreme events may be more important than changes in average temperature and precipitation
- Our results show that disturbances are important predictors of avian biodiversity patterns
- However, effects are context and guild specific