scholarly journals A Case Study: Looking at the Effects of Fragmentation on Genetic Structure in Different Life History Stages of Old-Growth Mountain Hemlock (Tsuga mertensiana)

2006 ◽  
Vol 98 (1) ◽  
pp. 73-78 ◽  
Author(s):  
D. Ally ◽  
K. Ritland
Keyword(s):  
Life History ◽  
Genetic Structure ◽  
Old Growth ◽  
Life History Stages ◽  
Tsuga Mertensiana

Fine-scale structure within a Trillium maculatum (Liliaceae) population

Botany ◽  
2009 ◽  
Vol 87 (3) ◽  
pp. 223-230 ◽  
Author(s):  
Alana N. Walker ◽  
Stephanie A. Foré ◽  
Beverly Collins
Keyword(s):  
Genetic Diversity ◽  
Life History ◽  
Genetic Structure ◽  
Spatial Genetic Structure ◽  
Vegetative Reproduction ◽  
Flowering Plants ◽  
Life History Stages ◽  
Genetic Diversity And Structure ◽  
Random Expectation ◽  
Perennial Herbs

In long-lived ant-dispersed perennial herbs of mesic forests, interactions among fruiting plants, seed dispersal, and plant mortality over life-history stages can create demographic and genetic structure. We investigated whether there was nonrandom variation in the distributions of individuals and in genetic diversity within and among life-history stages of the forest herb Trillium maculatum Raf. (Liliaceae). In 2002 and 2004, all T. maculatum plants in a 5 m × 5 m plot (1572 and 1379 individuals, respectively) were mapped and classified as seedling, one-leaf, three-leaf nonflowering, or flowering. Spatial distributions of plants within and across life-history stages were tested against random expectation. Allozyme analysis of 262 individuals from three life-history stages was used to assess genetic diversity and structure in 2004. The number of seedlings and the proportion of one-leaf plants differed between years, but the proportions of three-leaf nonflowering and flowering plants remained the same. There was little evidence of vegetative reproduction, but heterozygosity was low and there was evidence of inbreeding. Seedlings were clumped around flowering plants at distances up to 50 cm and one-leaf plants were clumped at distances up to 100 cm. There were no apparent genetic differences among life-history stages, nor any apparent spatial genetic structure among all sampled individuals. These results, like those of other demographic and allozyme studies of Trillium species, can be explained by restricted dispersal and random mortality.

Fine-scale genetic structure of life history stages in the food-deceptive orchid Orchis purpurea

2006 ◽  
Vol 15 (10) ◽  
pp. 2801-2808 ◽  
Author(s):  
HANS JACQUEMYN ◽  
REIN BRYS ◽  
KATRIEN VANDEPITTE ◽  
OLIVIER HONNAY ◽  
ISABEL ROLDÁN-RUIZ
Keyword(s):  
Life History ◽  
Genetic Structure ◽  
Fine Scale ◽  
Life History Stages

scholarly journals A Mechanistic Framework for Understanding the Effects of Climate Change on the Link Between Flowering and Fruiting Phenology

2021 ◽  
Vol 9 ◽  
Author(s):  
Manette E. Sandor ◽  
Clare E. Aslan ◽  
Liba Pejchar ◽  
Judith L. Bronstein
Keyword(s):  
Climate Change ◽  
Life History ◽  
Plant Species ◽  
Species Interactions ◽  
Direct Consequence ◽  
Functional Link ◽  
Fruiting Phenology ◽  
Life History Stages ◽  
Large Numbers

Phenological shifts are a widely studied consequence of climate change. Little is known, however, about certain critical phenological events, nor about mechanistic links between shifts in different life-history stages of the same organism. Among angiosperms, flowering times have been observed to advance with climate change, but, whether fruiting times shift as a direct consequence of shifting flowering times, or respond differently or not at all to climate change, is poorly understood. Yet, shifts in fruiting could alter species interactions, including by disrupting seed dispersal mutualisms. In the absence of long-term data on fruiting phenology, but given extensive data on flowering, we argue that an understanding of whether flowering and fruiting are tightly linked or respond independently to environmental change can significantly advance our understanding of how fruiting phenologies will respond to warming climates. Through a case study of biotically and abiotically dispersed plants, we present evidence for a potential functional link between the timing of flowering and fruiting. We then propose general mechanisms for how flowering and fruiting life history stages could be functionally linked or independently driven by external factors, and we use our case study species and phenological responses to distinguish among proposed mechanisms in a real-world framework. Finally, we identify research directions that could elucidate which of these mechanisms drive the timing between subsequent life stages. Understanding how fruiting phenology is altered by climate change is essential for all plant species but is particularly critical to sustaining the large numbers of plant species that rely on animal-mediated dispersal, as well as the animals that rely on fruit for sustenance.

scholarly journals The movement ecology of seagrasses

2014 ◽  
Vol 281 (1795) ◽  
pp. 20140878 ◽  
Author(s):  
Kathryn McMahon ◽  
Kor-jent van Dijk ◽  
Leonardo Ruiz-Montoya ◽  
Gary A. Kendrick ◽  
Siegfried L. Krauss ◽  
...  
Keyword(s):  
Life History ◽  
Clonal Growth ◽  
Movement Ecology ◽  
Future Research ◽  
The Novel ◽  
Long Distance ◽  
Spatial And Temporal Scales ◽  
Life History Stages ◽  
Research Areas ◽  
Time Movement

A movement ecology framework is applied to enhance our understanding of the causes, mechanisms and consequences of movement in seagrasses: marine, clonal, flowering plants. Four life-history stages of seagrasses can move: pollen, sexual propagules, vegetative fragments and the spread of individuals through clonal growth. Movement occurs on the water surface, in the water column, on or in the sediment, via animal vectors and through spreading clones. A capacity for long-distance dispersal and demographic connectivity over multiple timeframes is the novel feature of the movement ecology of seagrasses with significant evolutionary and ecological consequences. The space–time movement footprint of different life-history stages varies. For example, the distance moved by reproductive propagules and vegetative expansion via clonal growth is similar, but the timescales range exponentially, from hours to months or centuries to millennia, respectively. Consequently, environmental factors and key traits that interact to influence movement also operate on vastly different spatial and temporal scales. Six key future research areas have been identified.

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