Recent work proposes that passive directed dispersal (PDD) occurs when tracking resources leads animal vectors to sites that favor plant establishment. For example, wildland fire can attract seed-dispersing animals via the magnet effect while generating the environmental conditions that benefit common animal-dispersed plants. To test the hypothesis that frequent fire results in PDD in pine savanna, we first documented the effect of frequent fire on common bird-dispersed plants by measuring relative plant abundance and per-individual fruit production in a long-term replicated fire experiment. Focal plants occurred more frequently and produced more fruit per plant in plots burned biennially compared to plots that had been unburned for six decades. We then used a crossover Before-After Control-Impact (BACI) experiment to measure the responses of birds and bird-dispersed seed rain after fire. Despite fire increasing seed dispersal distance, the magnet effect of fire resulted in more seeds of focal plant taxa arriving in recent burns than in areas burned 1-2 years prior. Collectively, these results suggest that wildland fire promotes PDD. Given that fire is a globally pervasive process in terrestrial ecosystems, PDD may be an important mechanism shaping plant communities.

Investigators

David S. Mason
The Jones Center at Ichauway

Kevin M. Robertson
Tall Timbers Research Station

Phillip G. Hahn
Entomology and Nematology Department
University of Florida

Emilio M. Bruna
Wildlife Ecology and Conservation
University of Florida

John L. Willis
Southern Research Station
USDA Forest Service

Marcus A. Lashley
Wildlife Ecology and Conservation
University of Florida

Sampling information

The experiments and sampling occurred between 2020–2022 at Tall Timbers Research Station in Tallahassee, Florida. USA.

Sharing and Accessing Information

Please contact the primary author (david.mason@jonesctr.org) for advice or further context.

Methodology

README: Data from: Fire enables passive directed dispersal by birds

Description of data and file structure

This data comprises ten spreadsheets related to passive directed dispersal by birds after fire across two distinct experimental frameworks. The first subset of data (1–3) characterizes vegetation and fruit production within a long-term fire-frequency experiment. The second subset (4–10) focuses on bird-mediated seed dispersal at artificial perches above seed traps in a second experiment embedded within a frequent-fire landscape. Some gaps exist due to environmental and technical constraints, including severe weather and intermittent game camera malfunctions. These brief periods of missing data are denoted as NA within the spreadsheets.

Clean data files

File name	Description
Long-term-veg-focal-trials.csv	Presence/absence for focal taxa on vegetation transects experiment 1(long-term fire frequency / fire exclusion)
Long-term-veg-focal-counts.csv	Counts for focal taxa on vegetation transectsexperiment 1(long-term fire frequency / fire exclusion)
Fruit-availability-survey.csv	Fruit counts for focal taxa in experiment 1(long-term fire frequency / fire exclusion)
1_Birds-annual.csv	Annual counts of seed-dispersing birds on artificial perches. Data from game cameras in experiment 2 (magnet effect)
3_Birds-scat.csv	Binomial detection of defecation events on artificial perches for individual observations of seed-dispersing birds. Data from game cameras in experiment 2 (magnet effect)
4_Perch-availability.csv	Distance, species, and foliage status of three nearest lower midstory perches
3_TT-seed-removal.csv	Results of seed addition trials at seed traps
4_TT-fruit-survey.csv	1 m fruit transects for presence/absence of focal taxa at seed traps
10_TT-seeds-species-annual.csv	Raw and adjusted annual seed totals for each species at each trap

Data specific information for:

Long-term-veg-focal-trials.csv

Variable	Values	Units	Explanation
PLOT	DRAINAGE, NB66, UNBURN, W2A, W2B, W2C, W75	Categorical	Locations of plant surveys (n = 7)
TREATMENT	CONTROL, FIRE	Categorical	Sites burned biennially or remain fire-excluded (~60 years of no fire)
TRANSECT	DRAINAGE.1, DRAINAGE.2, DRAINAGE.3, NB66.1, NB66.2, NB66.3, NB66.4, Unburned.1, Unburned.2, Unburned.3, Unburned.4, Unburned.5, Unburned.6, W2A.1, W2A.2, W2A.3, W2A.4, W2A.5, W2A.6, W2B.1, W2B.2, W2B.3, W2B.4, W2B.5, W2B.6, W2C.1, W2C.2, W2C.3, W2C.4, W2C.5, W2C.6, W75.1, W75.2, W75.3	Categorical	Individual 30 m transects (1 m intercept) inside each location (n = 33)
SPECIES	CAAM2, RHCO, RUBUS	Categorical	Focal species: CAAM2 = Callicarpa americana, RHCO = Rhus copallinum, and RUBUS = Rubus sp.
SUCCESS	0–8	Integer	Number of plants that are focal taxa
FAILURE	0–57	Integer	Number of plants that are not focal taxa
TOTAL	0–57	Integer	Total number of plants in transect

Data specific information for:

Long-term-veg-focal-counts.csv

Variable	Values	Units	Explanation
PLOT	DRAINAGE, NB66, UNBURN, W2A, W2B, W2C, W75	Categorical	Locations of plant surveys (n = 7)
TREATMENT	CONTROL, FIRE	Categorical	Sites burned biennially or remain fire-excluded (~60 years of no fire)
TRANSECT	DRAINAGE.1, DRAINAGE.2, DRAINAGE.3, NB66.1, NB66.2, NB66.3, NB66.4, Unburned.1, Unburned.2, Unburned.3, Unburned.4, Unburned.5, Unburned.6, W2A.1, W2A.2, W2A.3, W2A.4, W2A.5, W2A.6, W2B.1, W2B.2, W2B.3, W2B.4, W2B.5, W2B.6, W2C.1, W2C.2, W2C.3, W2C.4, W2C.5, W2C.6, W75.1, W75.2, W75.3	Categorical	Individual 30 m transects (1 m intercept) inside each location (n = 33)
SPECIES	CAAM2, RHCO, RUBUS	Categorical	Focal species: CAAM2 = Callicarpa americana, RHCO = Rhus copallinum, and RUBUS = Rubus sp.
DETECTIONS	0–8	Integer	Total number of focal taxa detections in transect

Data specific information for:

Fruit-availability-survey.csv

Variable	Values	Units	Explanation
DATE	10/4/2022–7/3/2024	Month/Day/Year
PLOT	DRAINAGE, NB66, UNBURN, W2A, W2B, W2C, W75		Locations of fruit surveys (n = 7)
TREATMENT	CONTROL, FIRE	Categorical	Sites burned biennially or remain fire-excluded (~60 years of no fire)
SPECIES	CAAM2, RHCO, RUBUS	Categorical	Focal species: CAAM2 = Callicarpa americana, RHCO = Rhus copallinum, and RUBUS = Rubus sp.
FRUIT	0–1,376	Integer	# of fruit on individual plant
NOTE			Used to cross-reference site names

Data specific information for:

1_Birds-annual.csv

Variable	Values	Units	Explanation
SITE	1, 4, 6, 7, 8, 17	Categorical	Sites consisting of paired plots (n = 6)
BURN.YR	B,C	Categorical	Identifies plots within sites by which year they were burned. B = first year, C = second year
TRAP	A, B, C	Categorical	Identifier for traps within paired plots (n = 3 per plot, n = 6 per site)
BURN	Y, N	Categorical	Y is < 1 year since fire, N is 1-2 years since fire
DETECTIONS	4–495	Integer	Number of annual bird observations at individual trap

Data specific information for:

3_Birds-scat.csv

Variable	Values	Units	Explanation
SITE	1, 4, 6, 7, 8, 17	Categorical	Sites consisting of paired plots (n = 6)
BURN.YR	B,C	Categorical	Identifies plots within sites by which year they were burned. B = first year, C = second year
TRAP	A, B, C	Categorical	Identifier for traps within paired plots (n = 3 per plot, n = 6 per site)
BURN	Y, N	Binary	Y is < 1 year since fire, N is 1-2 years since fire
DATE.TIME	4/15/20 17:18– 3/24/22 11:20	Month/Day/Year HH:MM	Date and time of bird observation
DATE	4/15/20–3/24/22	Month/Day/Year	Date of bird observation
SPECIES	American crow, American goldfinch, American robin, Bachman's sparrow, Blue jay, Blue-gray gnatcatcher, Brown thrasher, Brown-headed cowbird, Brown-headed nuthatch, Carolina chickadee, Carolina wren, Chipping sparrow, Common yellowthroat, Downy woodpecker, Eastern bluebird, Eastern kingbird, Eastern phoebe, Eastern towhee, Eastern wood-pewee, Grackle, Gray catbird, Great crested flycatcher, Hairy woodpecker, House finch, House wren, Indigo bunting, Mourning dove, Northern bobwhite, Northern cardinal, Northern flicker, Northern mockingbird, Orchard oriole, Passerellidae sparrow sp., Red-bellied woodpecker, Red-eyed vireo, Red-headed woodpecker, Red-winged blackbird, Rose-breasted grosbeak, Setophaga sp., Summer tanager, Tufted titmouse, Unknown finch, Unknown passerine, Unknown songbird, Unknown sparrow, Unknown thrush, Unknown woodpecker, Unknown wren, White-crowned sparrow, Yellow-billed cuckoo, Yellow-breasted chat, Yellow-throated vireo	Categorical	Taxon of bird observation
SCAT	0/1	Binary	Indicates whether a defecation event is observed for the bird

Data specific information for:

4_Perch-availability.csv

Variable	Values	Units	Explanation
DATE	9/5/21–2/20/22	Month/Day/Year	Date of sample
SITE	1, 4, 6, 7, 8, 17	Categorical	Sites consisting of paired plots (n = 6)
BURN.YEAR	B, C	Categorical	Identifies plots within sites by which year they were burned. B = first year, C = second year
TRAP	A, B, C	Categorical	Identifier for traps within paired plots (n = 3 per plot, n = 6 per site)
DISTANCE	0.89–10.22	Meters	Distance between seed trap and nearest artificial perch (n = 3 per trap)
SPECIES	CAAM, CACO, LIST, MYCE, PINUS, PRSE, QUERCUS, RHUS, UNKNOWN	Categorical	Taxon of measured perch (CAAM = Callicarpa americana, CACO = Carya cordiformis, LIST = Liquidambar styraciflua, MYCE = Myrica cerifera, PINUS = Pinus spp., PRSE = Prunus serotina, QUERCUS = Quercus spp., RHUS, = Rhus copallinum, UNKNOWN = unidentified species)
FOLIAGE	Y, N	Binary	Does the perch have foliage?
NOTES			Includes additional details on foliage, taxon, and NA status

Data specific information for:

3_TT-seed-removal.csv

Variable	Values	Units	Explanation
TRIAL	1–6	Categorical	Individual seed removal trials (sequential)
START.DATE	4/6/20–7/5/20	Month/Day/Year	Trial start date
END.DATE	5/4/20–7/26/20	Month/Day/Year	Trial end date
SITE	1, 4, 6, 7, 8, 17	Categorical	Sites consisting of paired plots (n = 6)
BURN.YR	B, C	Categorical	Identifies plots within sites by which year they were burned. B = first year, C = second year
TRAP	A, B, C	Categorical	Identifier for traps within paired plots (n = 3 per plot, n = 6 per site)
SPECIES	SIAL, HEAN, CAAN	Categorical	Species of seeds in trial (SIAL = Sinapsis alba, HEAN = Helianthus annuus, CAAN = Capsicum annuum)
START.SEEDS	10	Integer	Number of seeds for each species at the start of the trial
END.SEEDS	0–10	Integer	Number of seeds for each species at the end of the trial
NOTES			Additional notes on individual trials
SEEDS.RM	0–10	Integer	Number of seeds for each species lost during the trial
INTERVAL	2020-04-06—2020-05-04 / 2020-07-05—2020-07-26	Interval	Date range for each trial
TRIAL.LENGTH	6–28	Integer	Duration of each trial (days)
SEEDS.RM.RATE	0–1.33	Decimal	Seeds lost per day
SEEDS.RM.PROP	0.0–1.0	Decimal	Proportion of seeds lost

Data specific information for:

4_TT-fruit-survey.csv

Variable	Values	Units	Explanation
DATE	6/13/20–2/20/22	Month/Day/Year	Date of sample
SITE	1, 4, 6, 7, 8, 17	Categorical	Sites consisting of paired plots (n = 6)
BURN.YR	B, C	Categorical	B is < 1 year since fire, C is 1-2 years since fire
TRAP	A, B, C	Categorical	Identifier for traps within paired plots (n = 3 per plot, n = 6 per site)
DIRECTION	N, SE, SW	Categorical	Cardinal or subcardinal direction of fruit transect
DISTANCE	3–33	Integer	Meters from trap along the transect (1 m point intercept)
SPECIES	CAAM2, RHCO, RUBUS	Categorical	Focal taxa (CAAM2 = Callicarpa americana, RHUS = Rhus copallinum, RUBUS = Rubus sp.)
PLANT	0, 1	Binary	Was focal plant present at transect point?
FRUIT	0, 1	Binary	Was focal plant fruiting at transect point?

Data specific information for:

10_TT-seeds-species-annual.csv

Variable	Values	Units	Explanation
SITE	1, 4, 6, 7, 8, 17	Categorical	Sites consisting of paired plots (n = 6)
BURN.YR	B, C	Categorical	B is < 1 year since fire, C is 1-2 years since fire
TRAP	A, B, C	Categorical	Identifier for traps within paired plots (n = 3 per plot, n = 6 per site)
ID	1BA, 1BB, 1BC, 1CA, 1CB, 1CC, 4BA, 4BB, 4BC, 4CA, 4CB, 4CC, 6BA, 6BB, 6BC, 6CA, 6CB, 6CC, 7BA, 7BB, 7BC, 7CA, 7CB, 7CC, 8BA, 8BB, 8BC, 8CA, 8CB, 8CC, 17BA, 17BB, 17BC, 17CA, 17CB, 17CC	Categorical	Unique identifier for individual traps (n = 36)
UNIT	A, B, C, D, E, F, G, H, I, J, K, L	Categorical	Unique identifier for individual plots (n = 36)
BURN	Y/N	Binary	Y is < 1 year since fire, N is 1-2 years since fire
SPECIES	CAAM2, RHUS, RUBUS	Integer	Focal taxa (CAAM2 = Callicarpa americana, RHUS = Rhus copallinum, RUBUS = Rubus sp.)
RAW.SEEDS	0–1,090	Integer	Annual seed rain in individual traps for taxa
ADJ.RM	0–4,165	Integer	Annual seed rain in individual traps for taxa after adjusting for seed loss
ADJ.FRUIT	0–135,448	Integer	Annual seed rain in individual traps for taxa after adjusting for fruit availability
ADJ.SEEDS	0–517,412	Integer	Annual seed rain in individual traps for taxa after adjusting for seed loss and fruit availability

Fire promotes passive directed dispersal by birds

Data files

Abstract

Investigators

Sampling information

Sharing and Accessing Information

Methodology

README: Data from: Fire enables passive directed dispersal by birds

Description of data and file structure

Clean data files

Data specific information for:

Data specific information for:

Data specific information for:

Data specific information for:

Data specific information for:

Data specific information for:

Data specific information for:

Data specific information for:

Data specific information for:

Fire promotes passive directed dispersal by birds

Data files

Abstract

README: Fire enables passive directed dispersal by birds

Investigators

Sampling information

Sharing and Accessing Information

Methodology

README: Data from: Fire enables passive directed dispersal by birds

Description of data and file structure

Clean data files

Data specific information for:

Data specific information for:

Data specific information for:

Data specific information for:

Data specific information for:

Data specific information for:

Data specific information for:

Data specific information for:

Data specific information for:

Works referencing this dataset