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Twelve northern desert shrub communities having the same macroclimate but differing habitats were studies. Arranged in order of decreasing production of live stems plus current growth, the communities were: (1) Sarcobatus vermiculatus (9,172 kg/ha), (2) Grayia spinosa (7,412 kg/ha), (3) Artemisia tridentata (5,474 kg/ha), (4) Chrysothamnus nauseosus (4,836 kg/ha), (5) Atriplex confertifolia (3,194 kg/ha), (6) Eurotia lanata (2,026 kg/ha), (7) Hilaria jamesii-Atriplex confertifolia (1,995 kg/ha), (8) Atriplex corrugata (1,949 kg/ha), (9) Chrysothamnus greenii filifolius (1,866 kg/ha), (10) Atriplex nuttallii (1,309 kg/ha), (11) Elymus salinus (865 kg/ha), and (12) Tetradymia spinosa (564 kg/ha). The communities were...
Detrended, modelled first leaf dates for 856 sites across North America for the period 1900–2008 are used to examine how the El Niño Southern Oscillation (ENSO) and the Pacific Decadal Oscillation (PDO) separately and together might influence the timing of spring. Although spring (mean March through April) ENSO and PDO signals are apparent in first leaf dates, the signals are not statistically significant (at a 95% confidence level (p < 0.05)) for most sites. The most significant ENSO/PDO signal in first leaf dates occurs for El Niño and positive PDO conditions. An analysis of the spatial distributions of first leaf dates for separate and combined ENSO/PDO conditions features a northwest–southeast dipole that is...
Categories: Publication; Types: Citation; Tags: ENSO, PDO, phenology, spring
Habitat loss and alteration from land use change, species invasion, and more recently, climate change have reduced biodiversity and ecosystem function worldwide. Habitat decisions have important implications to individual fitness as well as population dynamics and community structure. Resource limitation, predation, competition, and unfavorable abiotic conditions all have the potential to influence survival and future reproductive potential. Understanding how changes to ecosystem structure and function impact species and populations of conservation concern is essential for conservation delivery to be effective. Similar to many migratory species, shorebird populations are declining worldwide and declines may be related...
Abstract (from http://www.ncbi.nlm.nih.gov/pubmed/26022481): Premise of the study: Salt marshes are highly productive and valuable ecosystems, providing many services on which people depend. Spartina alterniflora Loisel (Poaceae) is a foundation species that builds and maintains salt marshes. Despite this species' importance, much of its basic reproductive biology is not well understood, including flowering phenology, seed production, and the effects of flowering on growth and biomass allocation. We sought to better understand these life history traits and use that knowledge to consider how this species may be affected by climate change. Methods: We examined temporal and spatial patterns in flowering and seed...
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Larrea tridentata is a xerophytic evergreen shrub, dominant in the arid regions of the southwestern United States. We examined relationships between gasexchange characteristics, plant and soil water relations, and growth responses of large versus small shrubs of L. tridentata over the course of a summer growing season in the Chihuahuan Desert of southern New Mexico, USA. The soil wetting front did not reach 0.6 m, and soils at depths of 0.6 and 0.9 m remained dry throughout the summer, suggesting that L. tridentata extracts water largely from soil near the surface. Surface soil layers (max) occurred in early summer (21.3 � mol m-2 s-1), when pre-dawn xylem water potential (XWP) reached ca. -1 MPa. Although both...
Seasonal dynamics of arbuscular mycorrhizal (AM) colonization of Sporobolus wrightii and AM fungal communities were assessed at four riparian sites in south-east Arizona which represented upper terrace or lower floodplain habitats and perennial or intermittent river reaches. Colonization was co-ordinated with growth/reproductive stages of plants at three sites with higher levels from February to May when plants were primarily vegetative and lower levels in September and December during seed set and onset of dormancy. Fifteen species of AM fungi were associated with S. wrightii, includingGlomus , Acaulospora, Paraglomus and Archaeospora species. Species richness ranged from 9 to 13 AM fungal species per site. Published...
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This suite of datasets consists of phenology data on over 1000 species of plants and animals (2009-present) and data on lilacs and honeysuckles (1956-present), across the United States. The data were collected by citizen and professional observers, and archived and distributed by the USA National Phenology Network (www.usanpn.org). Protocols are available in Denny et al, 2014 and datum is WGS84. This collection represents a suite of three data products: 1) Status and Intensity Data (phenophase status records of presence or absence of the phenophase, as well as information about the intensity with which the phenophase was expressed for each individual plant or species of animal at a site, on each visit by an observer),...
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The USA National Phenology Network has available a series of gridded products enabling researchers to analyze daily Accumulated Growing Degree Days (AGDD) from 2016 through the current year. Heat accumulation is commonly used as a way of predicting the timing of phenological transitions in plants and animals. Products generated by the USA-NPN begin accumulation on January 1 and use either a 32F or 50F base temperature.
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It is well understood that plant phenology is sensitive to climate, however it is not so clear exactly how climate change might alter the spatial and temporal patterns of vegetation phenology. Satellite remote sensing offers a unique vantage point from which to observe phenological cycles across large regions. Although ubiquitous, cycles of green-up and brown-down are complex and exhibit great variability across space and time. Herbivore species such as elk, moose, and deer depend on the availability of herbaceous plants and deciduous shrubs for forage. These vegetation types are most nutritious for herbivores from early season to peak green-up, so characterizing vegetation cycles, or phenology, over the long term...
"Climate change is causing species to shift their phenology, or the timing of recurring life events such as migration and reproduction. This can potentially result in mismatches with food and habitat resources that negatively impact species and ecosystems. Numerous studies have evaluated phenological shifts in terrestrial species, particularly birds and plants, yet far fewer evaluations have been conducted for marine animals. This project sought to improve understanding of shifts in timing at the ecosystem-scale across the Gulf of Maine as well as by exploring marine species-specific case studies. Through stakeholder engagement and outreach across the Northeast region we formed an interdisciplinary working group...
Detrended, modelled first leaf dates for 856 sites across North America for the period 1900–2008 are used to examine how the El Niño Southern Oscillation (ENSO) and the Pacific Decadal Oscillation (PDO) separately and together might influence the timing of spring. Although spring (mean March through April) ENSO and PDO signals are apparent in first leaf dates, the signals are not statistically significant (at a 95% confidence level (p < 0.05)) for most sites. The most significant ENSO/PDO signal in first leaf dates occurs for El Niño and positive PDO conditions. An analysis of the spatial distributions of first leaf dates for separate and combined ENSO/PDO conditions features a northwest–southeast dipole that is...
Categories: Publication; Types: Citation; Tags: ENSO, PDO, phenology, spring
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The Green Wave Hypothesis posits that herbivore migration manifests in response to waves of spring green-up (i.e., green-wave surfing). Nonetheless, empirical support for the Green Wave Hypothesis is mixed, and a framework for understanding variation in surfing is lacking. In a population of migratory mule deer (Odocoileus hemionus), 31% surfed plant phenology in spring as well as a theoretically perfect surfer, and 98% surfed better than random. Green-wave surfing varied among individuals, and was unrelated to age or energetic state. Instead, the greenscape, which we define as the order, rate, and duration of green-up along migratory routes, was the primary factor influencing surfing. Our results indicate that...
Abstract (from http://onlinelibrary.wiley.com/doi/10.1111/gcb.12919/abstract;jsessionid=64EF530762E939D509B9B308CD377394.f03t04): Anthropogenic climate change has altered temperate forest phenology, but how these trends will play out in the future is controversial. We measured the effect of experimental warming of 0.6–5.0 °C on the phenology of a diverse suite of 11 plant species in the deciduous forest understory (Duke Forest, North Carolina, USA) in a relatively warm year (2011) and a colder year (2013). Our primary goal was to dissect how temperature affects timing of spring budburst, flowering, and autumn leaf coloring for functional groups with different growth habits, phenological niches, and xylem anatomy....
Assessments of the potential responses of animal species to climate change often rely on correlations between long-term average temperature or precipitation and species' occurrence or abundance. Such assessments do not account for the potential predictive capacity of either climate extremes and variability or the indirect effects of climate as mediated by plant phenology. By contrast, we projected responses of wildlife in desert grasslands of the southwestern United States to future climate means, extremes, and variability and changes in the timing and magnitude of primary productivity. We used historical climate data and remotely sensed phenology metrics to develop predictive models of climate-phenology relations...
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Two unique datasets on the abundance and morphology of the angel lichen moth (Cisthene angelus) in Grand Canyon, Arizona, USA were compiled to describe the phenology and life history of this common, but poorly known, species. The abundance data were collected from 2012 to 2013 through a collaboration with river runners in Grand Canyon National Park. These citizen scientists deployed light traps from their campsites for one hour each night of their expedition. Insects were preserved in ethanol on site, and returned to the Southwest Biological Science Center in Flagstaff, Arizona for analysis in the laboratory. A total of 2,437 light trap samples were sorted through, 903 of which contained C. angelus. In total, 73,841...
Impacts of long-term climate shifts on the dynamics of intact communities within species ranges are not well understood. Here, we show that warming and drying of the Southwestern United States over the last 25 years has corresponded to a shift in the species composition of Sonoran Desert winter annuals, paradoxically favoring species that germinate and grow best in cold temperatures. Winter rains have been arriving later in the season, during December rather than October, leading to the unexpected result that plants are germinating under colder temperatures, shifting community composition to favor slow growing, water-use efficient, cold-adapted species. Our results demonstrate how detailed ecophysiological knowledge...
Growth of vegetative and reproductive structures in Artemisia tridentata is temporally separated during the growing season; vegetative growth occurs during spring and early summer when soil moisture is most abundant, while reproductive growth occur during summer and fall when soil moisture may be limiting. Vegetative and reproductive structures may therefore exhibit contrasting efficiencies of resource acquisition and investment resulting from temporal differences in resource availability during their development. We examined the effect of water stress on growth, photosynthesis, and resource investment for vegetative and reproductive modules of Artemisia tridentata by applying supplemental water. No differences...
Directional climate change will have profound and lasting effects throughout society that are best understood through fundamental physical and biological processes. One such process is phenology: how the timing of recurring biological events is affected by biotic and abiotic forces. Phenology is an early and integrative indicator of climate change readily understood by nonspecialists. Phenology affects the planting, maturation, and harvesting of food and fiber; pollination; timing and magnitude of allergies and disease; recreation and tourism; water quantity and quality; and ecosystem function and resilience. Thus, phenology is the gateway to climatic effects on both managed and unmanaged ecosystems.
Categories: Publication; Types: Citation; Tags: biogeosciences, phenology
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This product consists of 29 datasets of tabular data and associated metadata for watershed characteristics of 1,530 study sites of the Surface Water Trends (SWT) project of the U.S. Geological Survey’s (USGS) National Water Quality Program (NWQP). The project is conducting national studies of trends in water quality of streams and rivers for periods ranging from 10 to 40 years, between 1972 and 2012. The data here include both static and time-series characteristics. Static data include primarily physical characteristics which have changed little over this period, such as geology, soils, and topography. Time-series data represent characteristics which may or may not have changed over time, such as land use, agricultural...
Categories: Data; Types: Citation; Tags: Atmospheric Deposition, Basin Morphology, Census of Agriculture, Conterminous US, Crop Practices, All tags...


map background search result map search result map Effects of plant size and water relations on gas exchange and growth of the desert shrub Larrea tridentata Phenology Observation Data Accumulated Growing Degree Days, Contiguous United States, 1981 - Current Year Angel Lichen Moth Abundance and Morphology Data, Grand Canyon, AZ, 2012 The Effects of Drought on Vegetation Phenology and Wildlife Watershed characteristics for study sites of the Surface Water Trends project, National Water Quality Program Daily Surfing Effects of plant size and water relations on gas exchange and growth of the desert shrub Larrea tridentata Angel Lichen Moth Abundance and Morphology Data, Grand Canyon, AZ, 2012 Daily Surfing The Effects of Drought on Vegetation Phenology and Wildlife Watershed characteristics for study sites of the Surface Water Trends project, National Water Quality Program Phenology Observation Data Accumulated Growing Degree Days, Contiguous United States, 1981 - Current Year