knb-lter-sev.209.118417

Summary Information

Effects of Herbivores on Seed Banks of Grass and Shrublands at the Sevilleta National Wildlife Refuge, New Mexico (2004)

Creator:

Individual:

Terri Koontz

Organization:

SEV LTER

Physical Address:
Delivery Address:	Department of Biology, Castetter 167, University of New Mexico
City:	Albuquerque
Locality:	NM
Postal Code:	87131
Phone:	USA

Email:

tkoontz@sevilleta.unm.edu

System ID:

12632

Publication Date:

2011

Language:

english

Abstract:

Grazers and granivores have the potential to affect seed banks. Several studies have examined the impact of these herbivores on the aboveground vegetation, but few have looked at how they influence the seed bank. I asked whether both grazers and granivores alter the seed bank at the Sevilleta National Wildlife Refuge. Long-term experimental plots were installed in 1996 to exclude grazers and granivores from a grassland and shrubland. Soil samples were collected from these plots and seeds were germinated in a greenhouse. The grassland had significantly more species in its seed bank than the shrubland. Also, the seed bank composition differed significantly between the two sites. However, the number of species in the seed bank did not vary among herbivore treatments nor did total seed numbers vary among treatments at the grassland. At the shrubland, in contrast, plots that excluded both herbivores had fewer total seeds than control plots and plots where only grazers were excluded. Therefore, although herbivores play some role in the shrubland, herbivores do not reduce seed numbers at either site. Thus, seed bank size is not controlled by the consumption of seeds from these herbivores, but by some other factor (e.g. disturbance or abiotic events).

Keywords:
Keyword:	disturbance
Keyword Thesaurus:	Core Areas

Keywords:
Keyword:	herbivores
Keyword:	germination
Keyword:	soil
Keyword:	deserts
Keyword:	grasslands
Keyword:	seeds
Keyword:	vegetation
Keyword:	seed banks
Keyword Thesaurus:	LTER Controlled Vocabulary

Additional Information:

Additional Information on the Data Collection Period Soil samples were taken in mid March and October of 2004. Additional Study Area Information Study Area 1Study Area Name: Five Points Grass Core SiteStudy Area Location: Five Points is the general area which emcompasses the Black Grama Grassland (known as Five Points Grassland) and Creosote Core (Five Points Larrea) study sites and the transition between Chihuahuan Desert Scrub and Desert Grassland habitats. Both core sites are subject to intensive research activities, including measurements of NPP, phenology, pollinator diversity, and ground dwelling arthropod and rodent populations. There are drought rain-out shelters in both the Grassland and Creosote sites, as well as another set in the mixed ecotone with co-located ET Towers. The grassland Small Mammal Exclosure Study is located here, as well as many plots related to patch mapping and biotic transitions.Elevation: 1616 mVegetation: Desert Grassland habitat is ecotonal in nature and the Black Grama Core site is no exception, bordering Chihuahuan Desert Scrub at its southern boundary and Plains-Mesa Grassland at its northern, more mesic boundary. There is also a significant presence of shrubs, dominantly broom snakeweed (Gutierrezia sarothrae), along with less abundant fourwing saltbush (Atriplex canescens), Mormon tea (Ephedra torreyana), winterfat (Krascheninnikovia lanata), tree cholla (Opuntia imbricata), club cholla (O. clavata), desert pricklypear (O. phaeacantha), soapweed yucca (Yucca glauca), and what are presumed to be encroaching, yet sparsely distributed, creosotebush (Larrea tridentata). Characteristically, the dominant grass was black grama (Bouteloua eriopoda). Spike, sand, and mesa dropseed grasses (Sporobolus contractus, S. cryptandrus, S. flexuosus) and sand muhly (Muhlenbergia arenicola) could be considered co-dominant throughout, along with blue grama (B. gracilis) in a more mesic, shallow swale on the site. Notable forb species included trailing four o’clock (Allionia incarnata), horn loco milkvetch (Astragalus missouriensis), sawtooth spurge (Chamaesyce serrula), plains hiddenflower (Cryptantha crassisepala), blunt tansymustard (Descurania pinnata), wooly plaintain (Plantago patagonica), globemallow (Sphaeralcea wrightii), and mouse ear (Tidestromia lanuginosa).North Coordinate:34.3381South Coordinate:34.3381East Coordinate:106.717West Coordinate:106.717Study Area 2Study Area Name: Rio SaladoStudy Area Location: Rio Salado is about 3 km West I-25 just south of the Rio Salado. Site is accessed by taking San Acacia exit, going west and then taking the frontage road back north to the Sevilleta gate. After entering the refuge turn left after about .2 mi and take this road about 1.4 mi to a T in the road at the power lines. An earthen berm stops road travel here and the station is located about 300 m west on the blocked road.Elevation: 1503 mNorth Coordinate:34.296South Coordinate:0East Coordinate:0West Coordinate:106.9267

Intellectual Rights:

Data Policies

This dataset is released to the public and may be freely downloaded. Please keep the designated Contact person informed of any plans to use the dataset. Consultation or collaboration with the original investigators is strongly encouraged. Publications and data products that make use of the dataset must include proper acknowledgement of the Sevilleta LTER. Datasets must be cited as in the example below. Muldavin, E. 2004. Sevilleta LTER Fertilizer NPP Study Dataset. Albuquerque, NM: Sevilleta Long Term Ecological Research Site Database: SEV155. (Date of download) A copy of any publications using these data must be supplied to the Sevilleta LTER Information Manager.

Distribution:

Online:
URL:	http://sev.lternet.edu/node/2438

Coverage:

Geographic Goverage:

Geographic Description:

Location: Five Points Black Grama is on the transition between Chihuahuan Desert Scrub and Desert Grassland habitat. The site is subject to intensive research activity, including assessments of net primary productivity, phenology, and pollinator diversity, amongst other projects. It is the site of the unburned black grama (GU) component of the Burn NPP study. On August 4, 2009, a lightning-initiated fire began on the Sevilleta National Wildlife Refuge. By August 5, 2009, the fire had reached the Five Points Black Grama site. Portions of this site were burned, but not the entirety. See individual projects for further information on the effects of the burn. Vegetation: The Five Points Black Grama site is ecotonal in nature, bordering Chihuahuan Desert Scrub at its southern extent and Plains-Mesa Grassland at its northern, more mesic boundary. Characteristically, the dominant grass is black grama (Bouteloua eriopoda).,

Bounding Coordinates:

West Bounding Coordinates:

-106.736

East Bounding Coordinates:

-106.736

North Bounding Coordinates:

34.3331

South Bounding Coordinates:

34.3331

Bounding Altitude:
Altitude Minimum:	1615
Altitude Maximum:	1615
Altitude Units:	meter

Temporal Coverage:

Date Range:

Begin Date:
Calendar Date:	2004-03-01

End Date:
Calendar Date:	2004-10-01

Maintenance Information:

Description:
Metadata entered in Microsoft Access. 26 May 2009. tk

Contact:

Position Title:

Information Manager

Organization:

LTER Network Office

Physical Address:
Delivery Address:	UNM Biology Department, MSC03-2020
Delivery Address:	1 University of New Mexico
City:	Albuquerque
Locality:	NM
Postal Code:	87131-0001
Phone:	USA

Phone:

505 277-2535

Phone:

505 277-2541

Email:

tech-support@lternet.edu

URL:

http://www.lternet.edu

Contact:

Individual:

Information Manager Sevilleta LTER

Organization:

SEV LTER

Physical Address:
Delivery Address:	1 University of New Mexico
City:	Albuquerque
Postal Code:	87131

Phone:

(505) 277-2109

Phone:

(505) 277.5355

Email:

data-use@sevilleta.unm.edu

Publication Place:

Sevilleta LTER

Method Step:

Description:

Collecting and Processing soil samples Soil samples were collected at each site for each treatment in both mid March and October in 2004 for a total of 720 samples(15 samples per treatment x 3 treatments per block x 4 blocks per site x 2 sites x 2 seasons). There are 30 points between vegetation subplots in each of the Small Mammal Exclosure Study plots. Fifteen of these points were randomly selected from each plot. Soil samples were taken using a square electrical box with dimensions of 10cm(length) x 10cm (width) x 2cm(depth). These soil samples were then stored in paper bags and labeled with a unique sample number, indicating the site, block, treatment, and sample point, using a sharpie marker. Soil samples were then taken to the University of New Mexicos greenhouse. Due to space constraints in the greenhouse, only half of the samples from each season could be censused at one time. Therefore, I randomly selected half of the samples from each plot for each census. Soil samples were spread in a thin layer over a soil mixture containing half sand and half Metromix 360 in 8 x 11 flats. Flats were arranged into eight blocks each containing one sample from each plot to minimize variance due to greenhouse location. Control flats of sand and Metromix 360(with no field soil) were also distributed in the eight blocks to account for any seeds that might have contaminated the sand. The samples were then watered using a sprinkler system three times a day for five-minute durations where the thermostat temperature ranged from 16 to 25 Celsius for seven weeks. All seedlings were counted and identified to species. These procedures were repeated for the remaining half of the soil samples for each season.

Quality Control:

Description:
Data were visually assessed for any errors.

Data Table:

Entity Name:

sev209_seedbank_20111115.txt

Entity Description:

Terri Koontz seed bank study done at SMES sites

Object Name:

sev209_seedbank_20111115.txt

Data Format:

Text Format:

Number of Header Lines:

Number of Footer Lines:

Attribute Orientation:

column

Simple Delimited:
Field Delimiter:	,

Distribution:

Online:
URL:	https://pasta.lternet.edu/package/data/eml/knb-lter-sev/209/118417/7c7f4ad54e4c252a4cab46098ea75d7c

Coverage:

Temporal Coverage:
Calendar Date:	2011-11-15

Attribute List:

Attribute Name:

sample

Attribute Label:

sample

Attribute Definition:

The unique number of a sample.

Storage Type:

string

Measurement Scale:

Nominal:

Non Numeric Domain:

Text Domain:
Definition:	The unique number of a sample.

Attribute Name:

site

Attribute Label:

site

Attribute Definition:

The site at which data was collected.

Storage Type:

string

Measurement Scale:

Nominal:

Non Numeric Domain:

Enumerated Domain:

Code Definition:
Code:	C
Definition:	Rio Salado Creosote Site

Code Definition:
Code:	G
Definition:	Black Grama Site

Attribute Name:

Block

Attribute Label:

blk

Attribute Definition:

Number of block where data collected, ranging from 1 to 4

Storage Type:

string

Measurement Scale:

Nominal:

Non Numeric Domain:

Text Domain:
Definition:	Number of block where data collected, ranging from 1 to 4

Attribute Name:

trt

Attribute Label:

trt

Attribute Definition:

Plot treatment.

Storage Type:

string

Measurement Scale:

Nominal:

Non Numeric Domain:

Enumerated Domain:

Code Definition:
Code:	C
Definition:	Control

Code Definition:
Code:	L
Definition:	Lagomorph exclosure

Code Definition:
Code:	R
Definition:	Rodent and Lagomorph exclosure

Attribute Name:

season

Attribute Label:

season

Attribute Definition:

Season in which the data were collected

Storage Type:

string

Measurement Scale:

Nominal:

Non Numeric Domain:

Enumerated Domain:

Code Definition:
Code:	s
Definition:	spring

Code Definition:
Code:	f
Definition:	fall

Attribute Name:

germination time

Attribute Label:

ghtime

Attribute Definition:

soil samples from both spring and fall were separated into two germination times due to space constraints in the greenhouse

Storage Type:

string

Measurement Scale:

Nominal:

Non Numeric Domain:

Enumerated Domain:

Code Definition:
Code:	1
Definition:	first germination time

Code Definition:
Code:	2
Definition:	second germination time

Attribute Name:

species

Attribute Label:

species

Attribute Definition:

the species, total seed count of all species, or percent cover of different ground covers (litter, rock, etc.)

Storage Type:

string

Measurement Scale:

Nominal:

Non Numeric Domain:

Enumerated Domain:

Code Definition:
Code:	total
Definition:	total viable seeds that germinated

Code Definition:
Code:	litter
Definition:	the aboveground percent cover of litter in a 30 cm X 30 cm area

Code Definition:
Code:	gravel
Definition:	the aboveground percent cover of gravel in a 30 cm X 30 cm area

Code Definition:
Code:	rock
Definition:	the aboveground percent cover of rock in a 30 cm X 30 cm area. Rock was recorded instead of gravel when this physical variable was noticeably larger (approximately greater than 5 mm) than gravel.

Code Definition:
Code:	soil
Definition:	This is a calculated measurement where the remaining percent cover of the 30 cm x 30 cm area was designated as bare soil: soil

Code Definition:
Code:	canopy
Definition:	The above ground percent cover of vegetation that was not rooted in the sampling area (30 cm X 30 cm), but provided shade from overhanging vegetation.

Code Definition:
Code:	species
Definition:	Kartesz code

Attribute Name:

count

Attribute Label:

count

Attribute Definition:

seed counts for individual species

Measurement Scale:

Ratio:

Unit:

Standard Unit:

number

Precision:

Numeric Domain:
Number Type:	real