Competitive Effects and Responses Between Plant Species in a First-Year Old-Field Community

Ecology ◽  
1987 ◽  
Vol 68 (5) ◽  
pp. 1201-1210 ◽  
Author(s):  
T. E. Miller ◽  
P. A. Werner
Keyword(s):  
Plant Species ◽  
First Year ◽  
Old Field ◽  
Competitive Effects

Competitive Impacts of Means-Tested Vouchers on Public School Performance: Evidence from Louisiana

2021 ◽  
Vol 16 (1) ◽  
pp. 66-91 ◽  
Author(s):  
Anna J. Egalite ◽  
Jonathan N. Mills
Keyword(s):  
Public Schools ◽  
School Choice ◽  
Low Income ◽  
Private School ◽  
Fixed Effects ◽  
Policy Implications ◽  
First Year ◽  
Competitive Effects ◽  
Scholarship Program ◽  
Sudden Injection

Given the significant growth rate and geographic expansion of private school choice programs over the past two decades, it is important to examine how traditional public schools respond to the sudden injection of competition for students and resources. Although prior studies of this nature have been limited to Florida and Milwaukee, using multiple analytic strategies this paper examines the competitive impacts of the Louisiana Scholarship Program (LSP) to determine its achievement impacts on students in affected public schools. Serving 4,954 students in its first year of statewide expansion, this targeted school voucher program provides public funds for low-income students in low-performing public schools to enroll in participating private schools across the state of Louisiana. Using (1) a school fixed effects approach and (2) a regression discontinuity framework to examine the achievement impacts of the LSP on students in affected public schools, this competitive effects analysis reveals neutral to positive impacts that are small in magnitude. Policy implications are discussed.

scholarly journals Plant community diversity and composition provide little resistance to Juniperus encroachment

Botany ◽  
2008 ◽  
Vol 86 (12) ◽  
pp. 1416-1426 ◽  
Author(s):  
Amy C. Ganguli ◽  
David M. Engle ◽  
Paul M. Mayer ◽  
Eric C. Hellgren
Keyword(s):  
Species Richness ◽  
Species Diversity ◽  
Species Composition ◽  
Plant Species ◽  
Plant Community ◽  
Tallgrass Prairie ◽  
Abiotic Factors ◽  
Community Diversity ◽  
Oak Forest ◽  
Old Field

Widespread encroachment of the fire-intolerant species Juniperus virginiana  L. into North American grasslands and savannahs where fire has largely been removed has prompted the need to identify mechanisms driving J. virginiana encroachment. We tested whether encroachment success of J. virginiana is related to plant species diversity and composition across three plant communities. We predicted J. virginiana encroachment success would (i) decrease with increasing diversity, and (ii) J. virginiana encroachment success would be unrelated to species composition. We simulated encroachment by planting J. virginiana seedlings in tallgrass prairie, old-field grassland, and upland oak forest. We used J. virginiana survival and growth as an index of encroachment success and evaluated success as a function of plant community traits (i.e., species richness, species diversity, and species composition). Our results indicated that J. virginiana encroachment success increased with increasing plant richness and diversity. Moreover, growth and survival of J. virginiana seedlings was associated with plant species composition only in the old-field grassland and upland oak forest. These results suggest that greater plant species richness and diversity provide little resistance to J. virginiana encroachment, and the results suggest resource availability and other biotic or abiotic factors are determinants of J. virginiana encroachment success.

Fine root growth and demographic responses to nutrient patches in four old-field plant species

Oecologia ◽  
1993 ◽  
Vol 95 (1) ◽  
pp. 61-64 ◽  
Author(s):  
Katherine L. Gross ◽  
Andrew Peters ◽  
Kurt S. Pregitzer
Keyword(s):  
Root Growth ◽  
Plant Species ◽  
Fine Root ◽  
Old Field ◽  
Nutrient Patches ◽  
Field Plant ◽  
Fine Root Growth ◽  
Demographic Responses

Spatial and temporal patterns of postdispersal seed predation

1991 ◽  
Vol 69 (2) ◽  
pp. 428-436 ◽  
Author(s):  
Christopher J. Whelan ◽  
Mary F. Willson ◽  
Charles A. Tuma ◽  
Isabel Souza-Pinto
Keyword(s):  
Plant Species ◽  
Seed Predation ◽  
Temporal Patterns ◽  
Spatial And Temporal Patterns ◽  
Old Field ◽  
Plant Recruitment ◽  
Seed Loss ◽  
Open Forest ◽  
Forest Plant Species ◽  
Diffuse Mutualism

We experimentally examined spatial and temporal patterns of postdispersal seed predation of vertebrate-dispersed plant species in temperate woodland and old-field habitats. Rodents were the principal predators. Rates of seed loss varied with microhabitat (near logs, tree trunks, and open forest floor), macrohabitat (old field, forest), plant species, year, and time of dispersal within a year. Levels of final mortality (= mortality at final census) did not vary with microhabitat or time of dispersal but did vary between macrohabitats, plant species, and years. The variability of our results (i) indicates the importance of dispersing many seeds into many different types of micro- and macro-habitats, (ii) supports the view of a diffuse mutualism between plants and their vertebrate dispersers, and (iii) suggests that to detect important trends in patterns of postdispersal seed predation, and ultimately plant recruitment, longer term studies are imperative. Key words: community structure, seed predation, rodents, plant populations, plant recruitment, vertebrate seed dispersal.

Sign in / Sign up

Export Citation Format

Share Document