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Full-Text Articles in Forest Sciences

Effects Of A Prescribed Burn On Tree- And Herb-Layer Vegetation In A Post Oak (Quercus Stellata) Dominated Flatwoods, Rebecca W. Dolan Jun 2010

Effects Of A Prescribed Burn On Tree- And Herb-Layer Vegetation In A Post Oak (Quercus Stellata) Dominated Flatwoods, Rebecca W. Dolan

Rebecca W. Dolan

Post oak flatwoods are an unusual plant community type dominated by even-aged and uniformly sized post oaks (Quercus stellata) growing along level terraces of the Ohio River. Historical evidence exists that fire may play a role in the maintenance of the open canopy and poorly-developed understory characteristic of this community type (Dolan and Menges. 1989). The results of summer vegetation surveys taken yearly from 1989 to 1992 in a post oak flatwoods in southwestern Indiana that was subjected to a prescribed bum in the spring of 1989 are reported in this paper. The objective of the study was to determine …


Effects Of A Prescribed Burn On Tree- And Herb-Layer Vegetation In A Post Oak (Quercus Stellata) Dominated Flatwoods, Rebecca W. Dolan Jun 2010

Effects Of A Prescribed Burn On Tree- And Herb-Layer Vegetation In A Post Oak (Quercus Stellata) Dominated Flatwoods, Rebecca W. Dolan

Rebecca W. Dolan

Post oak flatwoods are an unusual plant community type dominated by even-aged and uniformly sized post oaks (Quercus stellata) growing along level terraces of the Ohio River. Historical evidence exists that fire may play a role in the maintenance of the open canopy and poorly-developed understory characteristic of this community type (Dolan and Menges. 1989). The results of summer vegetation surveys taken yearly from 1989 to 1992 in a post oak flatwoods in southwestern Indiana that was subjected to a prescribed bum in the spring of 1989 are reported in this paper. The objective of the study was to determine …


Effects Of A Prescribed Burn On Tree- And Herb-Layer Vegetation In A Post Oak (Quercus Stellata) Dominated Flatwoods, Rebecca W. Dolan Jun 2010

Effects Of A Prescribed Burn On Tree- And Herb-Layer Vegetation In A Post Oak (Quercus Stellata) Dominated Flatwoods, Rebecca W. Dolan

Rebecca W. Dolan

Post oak flatwoods are an unusual plant community type dominated by even-aged and uniformly sized post oaks (Quercus stellata) growing along level terraces of the Ohio River. Historical evidence exists that fire may play a role in the maintenance of the open canopy and poorly-developed understory characteristic of this community type (Dolan and Menges. 1989). The results of summer vegetation surveys taken yearly from 1989 to 1992 in a post oak flatwoods in southwestern Indiana that was subjected to a prescribed bum in the spring of 1989 are reported in this paper. The objective of the study was to determine …


Capturing Genetic Variation During Ecological Restorations: An Example From Kankakee Sands In Indiana, Rebecca W. Dolan, Deborah L. Marr, Andrew Schnabel Apr 2010

Capturing Genetic Variation During Ecological Restorations: An Example From Kankakee Sands In Indiana, Rebecca W. Dolan, Deborah L. Marr, Andrew Schnabel

Rebecca W. Dolan

Genetic variation in populations, both natural and restored, is usually considered crucial for response to short term environmental stresses and for long term evolutionary change. To have the best chance of successful long-term survival, restored populations should reflect the extant variation found in remnants, but restored sites may suffer from genetic bottlenecks as a result of founder effects. Kankakee Sands is a large-scale restoration being conducted by The Nature Conservancy (TNC) in northwestern Indiana. Our goal was to test for loss of genetic variation in restored plant populations by comparing them with TNC’s seed source nursery and with local remnant …


Capturing Genetic Variation During Ecological Restorations: An Example From Kankakee Sands In Indiana, Rebecca W. Dolan, Deborah L. Marr, Andrew Schnabel Apr 2010

Capturing Genetic Variation During Ecological Restorations: An Example From Kankakee Sands In Indiana, Rebecca W. Dolan, Deborah L. Marr, Andrew Schnabel

Rebecca W. Dolan

Genetic variation in populations, both natural and restored, is usually considered crucial for response to short term environmental stresses and for long term evolutionary change. To have the best chance of successful long-term survival, restored populations should reflect the extant variation found in remnants, but restored sites may suffer from genetic bottlenecks as a result of founder effects. Kankakee Sands is a large-scale restoration being conducted by The Nature Conservancy (TNC) in northwestern Indiana. Our goal was to test for loss of genetic variation in restored plant populations by comparing them with TNC’s seed source nursery and with local remnant …


Comparative Genetics Of Seven Plants Endemic To Florida’S Lake Wales Ridge, Eric S. Menges, Rebecca W. Dolan, Rebecca Yahr, Doria R. Gordan Apr 2010

Comparative Genetics Of Seven Plants Endemic To Florida’S Lake Wales Ridge, Eric S. Menges, Rebecca W. Dolan, Rebecca Yahr, Doria R. Gordan

Rebecca W. Dolan

Here we submit that mathematical tools used in population viability analysis can be used in conjunction with floristic and faunistic surveys to predict changes in biogeographic range. We illustrate our point by summarizing the results of a demographic study of Lobelia boykinii. In this study we used deterministic and stochastic matrix models to estimate the growth rate and to predict the time to extinction for three populations growing in the Carolina bays. The stochastic model better discriminated among the fates of the three populations. It predicted extinction for two populations in the next 25 years but no extinction of the …


Genetic Variation In Past And Current Landscapes: Conservation Implications Based On Six Endemic Florida Scrub Plants, Eric S. Menges, Rebecca W. Dolan, Robert Pickert, Rebecca Yahr, Doria R. Gordon Mar 2010

Genetic Variation In Past And Current Landscapes: Conservation Implications Based On Six Endemic Florida Scrub Plants, Eric S. Menges, Rebecca W. Dolan, Robert Pickert, Rebecca Yahr, Doria R. Gordon

Rebecca W. Dolan

If genetic variation is often positively correlated with population sizes and the presence of nearby populations and suitable habitats, landscape proxies could inform conservation decisions without genetic analyses. For six Florida scrub endemic plants (Dicerandra frutescens, Eryngium cuneifolium, Hypericum cumulicola, Liatris ohlingerae, Nolina brittoniana, and Warea carteri), we relate two measures of genetic variation, expected heterozygosity and alleles per polymorphic locus (APL), to population size and landscape variables. Presettlement areas were estimated based on soil preferences and GIS soils maps. Four species showed no genetic patterns related to population or landscape factors. The other two species showed significant but inconsistent …


The Rare, Serpentine Endemic Streptanthus Morrisonii (Brassicaceae) Species Complex, Revisited Using Isozyme Analysis, Rebecca W. Dolan Mar 2010

The Rare, Serpentine Endemic Streptanthus Morrisonii (Brassicaceae) Species Complex, Revisited Using Isozyme Analysis, Rebecca W. Dolan

Rebecca W. Dolan

The Streptanthus morrisonii (Brassicaceae) complex is a group of six narrowly-distributed obligate serpentine endemic taxa whose habitat is threatened by geothermal development. Isozyme analysis of this little-studied complex supports the delineation of two species, S. morrisonii and S. brachiatus, but is at odds with the treatment of two subspecies based on morphology. These results may be influenced by small sample sizes but genetic studies of other Streptanthus taxa have shown patterns of relatedness that often transgress subspecies boundaries based on morphology. The present study further shows that members of the S. morrisonii complex share high genetic identity values (mean = …


Population Genetic Structure In Nolina Brittoniana (Agavaceae), A Plant Endemic To The Central Ridges Of Florida, Rebecca W. Dolan, Rebecca Yahr, Eric S. Menges Mar 2010

Population Genetic Structure In Nolina Brittoniana (Agavaceae), A Plant Endemic To The Central Ridges Of Florida, Rebecca W. Dolan, Rebecca Yahr, Eric S. Menges

Rebecca W. Dolan

Nolina brittoniana is endemic to the central ridges of peninsular Florida. Its scrub and sandhill habitats have suffered extensive anthropogenic modification. Analysis of isozymes from populations throughout its range revealed less genetic variation than generally reported for endemic plants. Populations were well differentiated, with significant clines in allele frequency along the north-south axis of distribution. Pair-wise F-statistics calculated at four levels of population geographic substructure revealed that current and inferred historical habitat patches had similar genetic structure. We found no evidence of recent bottlenecks or changes in genetic structure due to habitat loss and fragmentation, consistent with populations having always …


The Effects Of Seed Size And Maternal Origin On The Distribution Of Individual Plant Size In Ludwigia Leptocarpa (Onagraceae), Rebecca W. Dolan Mar 2010

The Effects Of Seed Size And Maternal Origin On The Distribution Of Individual Plant Size In Ludwigia Leptocarpa (Onagraceae), Rebecca W. Dolan

Rebecca W. Dolan

Seed size is normally distributed for many annual species, while mature plant size is frequently positively skewed. A study was conducted to determine the influence of seed size and the role of genetic differences in determining relative seedling size for Ludwigia leptocarpa. Seed size had a significant effect on percentage germination and time of seed germination but no effect on dry weight or leaf area of seedlings. Seed size and spacing had a significant effect on seedling dry weight for plants grown under competition, while relative day of emergence had no effect. Familial (genetic) differences were found in average seed …


Patterns Of Isozyme Variation In Relation To Population Size, Isolation, And Phytogeographic History In Royal Catchfly, Rebecca W. Dolan Mar 2010

Patterns Of Isozyme Variation In Relation To Population Size, Isolation, And Phytogeographic History In Royal Catchfly, Rebecca W. Dolan

Rebecca W. Dolan

The distribution of genetic variation within and among plant populations is influenced by both contemporary and historical factors. I used isozyme analysis of band phenotypes to examine genetic structure in the rare prairie forb Silene regia. Relationships between current-day population size, isolation, and phenotypic variation were assessed for 18 populations in two regions with differing postglacial history. Western populations from unglaciated southern Missouri and Arkansas were more genetically diverse based on the Shannon-Weaver index (H) and a polymorphic index than were more eastern populations. These differences may be due to loss of variation with repeated founding of new populations in …


Conservation Implications Of Genetic Variation In Three Rare Species Endemic To Florida Rosemary Scrub, Rebecca W. Dolan, Rebecca Yahr, Eric S. Menges, Matthew Halfhill Mar 2010

Conservation Implications Of Genetic Variation In Three Rare Species Endemic To Florida Rosemary Scrub, Rebecca W. Dolan, Rebecca Yahr, Eric S. Menges, Matthew Halfhill

Rebecca W. Dolan

Habitat conversion and fire suppression during the last 50 yr have greatly reduced and altered Florida scrub vegetation, resulting in threats to the persistence of its unique flora. As part of a larger conservation project, we investigated patterns of isozyme variation in three rare perennial scrub plants with overlapping ranges endemic to Florida rosemary scrub on the Lake Wales Ridge. All three species have low levels of genetic variation, comparable to or lower than those generally reported for rare plants with restricted geographic ranges. Liatris ohlingerae has more than twice the expected heterozygosity of the other two species, with little …


Conservation Implications Of Genetic Variation In Three Rare Species Endemic To Florida Rosemary Scrub, Rebecca W. Dolan, Rebecca Yahr, Eric S. Menges, Matthew Halfhill Mar 2010

Conservation Implications Of Genetic Variation In Three Rare Species Endemic To Florida Rosemary Scrub, Rebecca W. Dolan, Rebecca Yahr, Eric S. Menges, Matthew Halfhill

Rebecca W. Dolan

Habitat conversion and fire suppression during the last 50 yr have greatly reduced and altered Florida scrub vegetation, resulting in threats to the persistence of its unique flora. As part of a larger conservation project, we investigated patterns of isozyme variation in three rare perennial scrub plants with overlapping ranges endemic to Florida rosemary scrub on the Lake Wales Ridge. All three species have low levels of genetic variation, comparable to or lower than those generally reported for rare plants with restricted geographic ranges. Liatris ohlingerae has more than twice the expected heterozygosity of the other two species, with little …


Genetic Diversity And Reproductive Biology In Warea Carteri (Brassicaceae), A Narrowly Endemic Florida Scrub Annual, Margaret E.K. Evans, Rebecca W. Dolan, Eric S. Menges, Doria R. Gordon Mar 2010

Genetic Diversity And Reproductive Biology In Warea Carteri (Brassicaceae), A Narrowly Endemic Florida Scrub Annual, Margaret E.K. Evans, Rebecca W. Dolan, Eric S. Menges, Doria R. Gordon

Rebecca W. Dolan

Carter's mustard (Warea carteri) is an endangered, fire-stimulated annual endemic of the Lake Wales Ridge, Florida, USA. This species is characterized by seed banks and large fluctuations in plant numbers, with increases occurring in postdisturbance habitat. We investigated the mating system, patterns of isozyme variation, and effective population sizes of W. carteri to better understand its population biology and to comment on reserve designs and management proposals relevant to this species. Warea carteri is self-compatible and autogamous, and probably largely selfing. Measures of genetic variation in W. carteri were lower than values reported for species with similar ecological and life …