Abstract：
PREMISE OF THE STUDY:Elucidating the factors that determine the abundance and distribution of species remains a central goal of ecology. It is well recognized that genetic differences among individual species can affect the distribution and species interactions of dependent taxa, but the ecological effects of genetic differences on taxa of the same trophic level remain much less understood. Our goal was to test the hypothesis that differences between related overstory tree species and their hybrids can influence the understory plant community in wild settings. METHODS:We conducted vegetation surveys in a riparian community with the overstory dominated by Populus fremontii, P. angustifolia, and their natural hybrids (referred to as cross types) along the Weber River in north central Utah, USA. Understory diversity and community composition, as well as edaphic properties, were compared under individual trees. KEY RESULTS:Diversity metrics differ under the three different tree cross types such that a greater species richness, diversity, and cover of understory plants exist under the hybrids compared with either of the parental taxa (30-54%, 40-48%, and 35-74% greater, respectively). The community composition of the understory also varied by cross type, whereby additional understory plant species cluster with hybrids, not with parental species. CONCLUSIONS:Genetic composition dictated by hybridization in the overstory can play a role in structuring the associated understory plants in natural communities-where a hybridized overstory correlates with a species-rich understory-and thus can have cascading effects on community members of the same trophic level. The underlying mechanism requires further investigation.
journal_name
Am J Botjournal_title
American journal of botanyauthors
Adams RI,Goldberry S,Whitham TG,Zinkgraf MS,Dirzo Rdoi
10.3732/ajb.1100137subject
Has Abstractpub_date
2011-10-01 00:00:00pages
1623-32issue
10eissn
0002-9122issn
1537-2197pii
ajb.1100137journal_volume
98pub_type
杂志文章abstract：:Chrysothamnus nauseosus (Asteraceae) is a complex polymorphic shrub species widely distributed in western North America. In a study of 86 populations belonging to 15 subspecies, achene mass varied among populations over a sevenfold range. Achene mass was closely correlated with capitulum size at the subspecies level, ...
journal_title：American journal of botany
pub_type： 杂志文章
doi：
更新日期：1997-04-01 00:00:00
abstract：UNLABELLED:• PREMISE OF THE STUDY:The evolution of invasiveness has been extensively studied in natural ecosystems; however, far less is known about the evolution of agricultural invasiveness, despite the major economic impact of weeds on crop productivity. Examining the population structure of recently arisen weeds c...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.3732/ajb.1400064
更新日期：2014-10-01 00:00:00
abstract：:The possible pathways of origin of two recently arisen introgressant forms of Senecio vulgaris (i.e., var. hibernicus and York radiate groundsel) were investigated in experimental crosses between tetraploid S. vulgaris var. vulgaris and the normally diploid S. squalidus. Comparison of the morphology of synthesized hyb...
journal_title：American journal of botany
pub_type： 杂志文章
doi：
更新日期：2000-08-01 00:00:00
abstract：:Pedilanthus coalcomanensis was described from specimens collected by George B. Hinton in 1941 but was not collected again until 1999, when we found it in a tropical deciduous forest near Tehuantepec, in Chinicuila, Michoacán, Mexico. After analyzing Hinton's original collection notes, we concluded that this is the typ...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.3732/ajb.89.9.1485
更新日期：2002-09-01 00:00:00
abstract：:The relationship between pollen and progeny performance has been a subject of many studies but the evidence for pollen-tube growth rate as an indicator of progeny fitness is equivocal. We used an anemophilous tree, Betula pendula, to examine the relationship between pollen-tube growth rate and seed and seedling perfor...
journal_title：American journal of botany
pub_type： 杂志文章
doi：
更新日期：2001-05-01 00:00:00
abstract：:The origin of polyploid Bromus species of section Genea was investigated using molecular data. This group of annual species native from the Old-World is composed of three diploids, two tetraploids, one hexaploid, and one octoploid. Molecular cloning, sequencing, and phylogenetic analyses were performed on several acce...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.3732/ajb.95.4.454
更新日期：2008-04-01 00:00:00
abstract：:The FAD2-1 microsomal omega-6 desaturase gene contains a large intron ( approximately 1133 bp [base pairs]) in the 5' untranslated region that may participate in gene regulation and, in GOSSYPIUM:, is evolving at an evolutionary rate useful for elucidating recently diverged lineages. FAD2-1 is single copy in diploid G...
journal_title：American journal of botany
pub_type： 杂志文章
doi：
更新日期：2001-01-01 00:00:00
abstract：:Detailed investigations on Lower Cretaceous Ephedra L. fossils (Gnetopsida) reveal morphological characters similar to those of extant Ephedra rhytidosperma Pachomova, including articulate branches with many fine longitudinal striations, a dichasial branching pattern, uni- or bi-ovulate cones with paired bracts, cones...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.3732/ajb.92.2.231
更新日期：2005-02-01 00:00:00
abstract：:Serpentine soils are a model system for the study of plant adaptation, speciation, and species interactions. Serpentine soil is an edaphically stressful, low productivity soil type that hosts stunted vegetation and a spectacular level of plant endemism. One of the first papers on serpentine plant endemism was by Arthu...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.3732/ajb.1300349
更新日期：2014-02-01 00:00:00
abstract：:Plant xylem must balance efficient delivery of water to the canopy against protection from air entry into the conduits via air-seeding. We investigated the relationship between tracheid allometry, end wall pitting, safety from air-seeding, and the hydraulic efficiency of conifer wood in order to better understand the ...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.3732/ajb.93.9.1265
更新日期：2006-09-01 00:00:00
abstract：:Paddy fields are one of the dominant anthropogenic sources of methane emission to the atmosphere, and the main passageway of methane from paddy soil is through the rice plant. However, the effect of aquatic weeds on methane emission from rice paddies has not been properly evaluated yet. Methane emission from weeded po...
journal_title：American journal of botany
pub_type： 杂志文章
doi：
更新日期：2001-06-01 00:00:00
abstract：PREMISE:The Eocene-Oligocene transition (EOT; 34-33 Ma) was marked by global cooling and increased seasonality and aridity, leading to a shift in North American floras from subtropical forests to deciduous hardwood forests similar to today. This shift is well documented taxonomically and biogeographically, but its ecol...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.1002/ajb2.1580
更新日期：2020-12-01 00:00:00
abstract：PREMISE OF THE STUDY:Koelreuteria (Sapindaceae) has four extant deciduous tree species, disjunctly distributed in eastern Asia and the Fiji Islands. While K. paniculata is widely cultivated, the biogeographic origin and evolutionary history of Koelreuteria remain unclear. METHODS:Fruits, pollen, wood, and leaves of cl...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.3732/ajb.1200415
更新日期：2013-02-01 00:00:00
abstract：PREMISE OF THE STUDY:While the effect of abiotic factors on leaf herbivory is well known, the relative importance of abiotic conditions influencing both mutualists and antagonists is less well understood. Species interactions could enhance or reduce the direct effects of abiotic factors, depending on how mutualists and...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.3732/ajb.1200460
更新日期：2013-04-01 00:00:00
abstract：PREMISE OF THE STUDY:Despite being highly fertile and occupying a large geographic region, the North American heartleaf bittercress (Cardamine cordifolia; Brassicaceae) has a puzzling triploid-like chromosome number (2n = 3x = 24). As most triploids are sterile, we embarked on a detailed analysis of the C. cordifolia g...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.3732/ajb.1500452
更新日期：2016-07-01 00:00:00
abstract：:In the southern Appalachian mountains a subcanopy species, Rhododendron maximum, inhibits the establishment and survival of canopy tree seedlings. One of the mechanisms by which seedlings could be inhibited is an allelopathic effect of decomposing litter or leachate from the canopy of R. maximum (R.m.) on seed germina...
journal_title：American journal of botany
pub_type： 杂志文章
doi：
更新日期：1999-11-01 00:00:00
abstract：PREMISE OF THE STUDY:Conifers are an important living seed plant lineage with an extensive fossil record spanning more than 300 million years. The group therefore provides an excellent opportunity to explore congruence and conflict between dated molecular phylogenies and the fossil record. METHODS:We surveyed the curr...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.1002/ajb2.1143
更新日期：2018-09-01 00:00:00
abstract：:Seedling establishment is central to population maintenance for nonclonal plant species. Plants with low recruitment rates are expected to have high survival rates, and life history theory indicates there should be a single curve for the trade-off between recruitment and mortality that applies to most or all plant spe...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.3732/ajb.91.7.1147
更新日期：2004-07-01 00:00:00
abstract：:Leaf habit correlates with multiple physiological traits. Understanding ecophysiology is therefore dependent on knowledge of leaf habit. A variety of leaf habits exists within forest understory plant communities. Oxalis acetosella is one such understory plant and has long been considered a wintergreen, meaning that it...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.3732/ajb.91.9.1371
更新日期：2004-09-01 00:00:00
abstract：:We developed an improved cytological protocol for producing high quality, light microscope images of plant meiotic chromosomes. Because the technique works on species with small genomes and thick microsporocyte cell walls, it should be useful for studying the wild relatives of Arabidopsis and other eudicots with small...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.3732/ajb.94.12.2063
更新日期：2007-12-01 00:00:00
abstract：PREMISE:Woody plants with photosynthetic stems are common in the drylands of the world; however, we know little about the origin(s) and geographical distribution of photosynthetic stems. Therefore, we set to answer the following questions: (1) Is stem photosynthesis phylogenetically conserved? (2) Do green-stemmed and ...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.1002/ajb2.1572
更新日期：2020-12-06 00:00:00
abstract：:The last decade has witnessed a resurgence in the study of the evolution of plant development, combining investigations in systematics, developmental morphology, molecular developmental genetics, and molecular evolution. The integration of phylogenetic studies, structural analyses of fossil and extant taxa, and molecu...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.3732/ajb.91.10.1726
更新日期：2004-10-01 00:00:00
abstract：:In volume 97(2) of the American Journal of Botany (pp. 268-275), we published an article entitled "Structural, physiological, and stable carbon isotopic evidence that the enigmatic Paleozoic fossil Prototaxites formed from rolled liverwort mats". Here, we respond to a letter and a commentary on our article in the pres...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.3732/ajb.1000172
更新日期：2010-07-01 00:00:00
abstract：PREMISE OF THE STUDY:General relationships among functional traits have been identified across species, but the forces shaping these relationships remain largely unknown. Adopting an approach from evolutionary biology, we studied similarities and differences in intrapopulation trait correlations among locally co-occurr...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.1002/ajb2.1146
更新日期：2018-09-01 00:00:00
abstract：:We demonstrated that "orchid mycorrhiza," a specialized mycorrhizal type, appeared in the common ancestor of the largest plant family Orchidaceae and that the fungal partner shifted from Glomeromycota to a particular clade of Basidiomycota in association with this character evolution. Several unique mycorrhizal charac...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.3732/ajb.0900101
更新日期：2009-11-01 00:00:00
abstract：PREMISE OF THE STUDY:Anatomical and morphological features of Satanocrater were studied to test hypotheses of xeric adaptations in the genus, which is endemic to arid tropical Africa. These features, together with molecular data, were used to test the phylogenetic placement of Satanocrater within the large plant family...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.3732/ajb.1100354
更新日期：2012-06-01 00:00:00
abstract：:Because leaf pubescence of the desert shrub Encelia farinosa increases in response to drought and influences photosynthesis and transpiration, we hypothesized that differences in water availability across the range of this species may result in genetic differentiation for pubescence and associated productivity traits....
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.3732/ajb.90.10.1481
更新日期：2003-10-01 00:00:00
abstract：PREMISE OF THE STUDY:Microsatellite markers were developed for the dove tree, Davidia involucrata (Cornaceae), a Tertiary relict currently endemic to China, to investigate its population genetics and phylogeography. METHODS AND RESULTS:Using the Fast Isolation by AFLP of Sequences Containing repeats (FIASCO) protocol,...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.3732/ajb.1100414
更新日期：2012-03-01 00:00:00
abstract：:The desert moss Syntrichia caninervis exhibits one of the most skewed sex ratios in the plant kingdom, with female individuals far outnumbering male individuals (exceeding 14♀:1♂). The "cost of sex hypothesis" derives from allocational theory and predicts that the sex which is most expensive should be the rarer sex. T...
journal_title：American journal of botany
pub_type： 杂志文章
doi：
更新日期：2000-11-01 00:00:00
abstract：UNLABELLED:• PREMISE OF THE STUDY:Island plants are over-exploited and "under-explored." Understanding the reproductive biology of plants, especially rare species, is fundamental to clarifying their evolution, estimating potential for change, and for creating effective conservation plans. Clarification of sexual syste...
journal_title：American journal of botany
pub_type： 杂志文章
doi：10.3732/ajb.1400486
更新日期：2015-03-01 00:00:00
