Grazers, browsers, and fire influence the extent and spatial pattern of tree cover in the Serengeti

2009 ◽  
Vol 19 (1) ◽  
pp. 95-109 ◽  
Author(s):  
Ricardo M. Holdo ◽  
Robert D. Holt ◽  
John M. Fryxell
Keyword(s):  
Spatial Pattern ◽  
Tree Cover

scholarly journals Patterns of shrub abundance and relationships with other plant types within the forest–tundra ecotone in northern Canada

2018 ◽  
Vol 4 (4) ◽  
pp. 691-709 ◽  
Author(s):  
Karen A. Harper ◽  
Amanda A. Lavallee ◽  
Pavel Dodonov
Keyword(s):  
Wavelet Analysis ◽  
Spatial Pattern ◽  
Soil Ph ◽  
Environmental Variables ◽  
Generalized Least Squares ◽  
Tree Cover ◽  
Cascading Effects ◽  
Forest Tundra ◽  
Plant Groups ◽  
Tall Shrub

Throughout the forest–tundra ecotone where trees and tall shrubs are becoming more abundant, knowledge of associations between shrubs and surrounding vegetation could inform predictions of their changing relationships. We assessed shrubs in 1 m × 1 m contiguous quadrats along two ∼450 m transects across tundra and ecotone landscapes near Churchill, Canada to determine patterns in relation to lakeshore edges, soil pH, microtopography, and other plant groups. We used wavelet analysis to assess patterns and generalized least squares for relationships with environmental variables. Shrubs were taller and more diverse at edges, particularly in tundra. The ecotone was more complex than tundra with greater variation in tall shrub and tree cover, shrub height, and microtopography. Shrub richness was positively correlated with microtopography but exhibited no relationship with pH. Bivariate relationships of shrubs with other plant groups varied for different scales. In tundra, shrub richness was negatively correlated with graminoids, forbs, and moss, but positively correlated with lichens within 1 m; opposite relationships were found at 4–60 m scales. Relationships in the ecotone were reversed and more complex at different scales. As trees encroach in the tundra, the spatial pattern of shrubs will become more complex at a variety of scales, likely with cascading effects on other plant types.

scholarly journals Tree spatial pattern within the forest–tundra ecotone: a comparison of sites across CanadaThis article is a contribution to the series Tree recruitment, growth, and distribution at the circumpolar forest–tundra transition.

2011 ◽  
Vol 41 (3) ◽  
pp. 479-489 ◽  
Author(s):  
Karen A. Harper ◽  
Ryan K. Danby ◽  
Danielle L. De Fields ◽  
Keith P. Lewis ◽  
Andrew J. Trant ◽  
...  
Keyword(s):  
Climate Change ◽  
Spatial Pattern ◽  
Patch Size ◽  
Forest Tree ◽  
Tree Cover ◽  
Site Specific ◽  
Forest Tundra ◽  
Local Variance ◽  
Tree Spatial Pattern ◽  
Subarctic Forest

Although many studies have focused on factors influencing treeline advance with climate change, less consideration has been given to potential changes in tree spatial pattern across the forest–tundra ecotone. We investigated trends in spatial pattern across the forest–tundra ecotone and geographical variation in the Yukon, Manitoba, and Labrador, Canada. Tree cover was measured in contiguous quadrats along transects up to 100 m long located in Forest, Ecotone, and Tundra sections across the forest–tundra transition. Spatial patterns were analyzed using new local variance to estimate patch size and wavelet analysis to determine the scale and amount of aggregation. Compared with the Forest, tree cover in the Ecotone was less aggregated at most sites, with fewer smaller patches of trees. We found evidence that shorter trees may be clumped at some sites, perhaps due to shelter from the wind, and we found little support for regular spacing that would indicate competition. With climate change, trees in the Ecotone will likely become more aggregated as patches enlarge and new patches establish. However, results were site-specific, varying with aspect and the presence of krummholz (stunted trees); therefore, strategies for adaptation of communities to climate change in Canada’s subarctic forest would need to reflect these differences.

Spatial Pattern Discrimination in Rats

2003 ◽  
Author(s):  
Kelly A. Digian ◽  
Michael Brown
Keyword(s):  
Spatial Pattern ◽  
Pattern Discrimination

Visual cues and spatial pattern learning

2001 ◽  
Author(s):  
Michael F. Brown ◽  
Sue Yang ◽  
Kelly Digian
Keyword(s):  
Spatial Pattern ◽  
Visual Cues ◽  
Pattern Learning

Spatial Pattern of Water Quality on Coral Reef Area Around Kaledupa Island

Jurnal Segara ◽  
2016 ◽  
Vol 12 (2) ◽  
pp. 99
Author(s):  
Hadiwijaya Lesmana Salim ◽  
Dini Purbani ◽  
Agustin Rustam ◽  
Yulius Yulius ◽  
Devi Suryono ◽  
...  
Keyword(s):  
Water Quality ◽  
Coral Reef ◽  
Spatial Pattern ◽  
Reef Area ◽  
Coral Reef Area
Sign in / Sign up

Export Citation Format

Share Document