Seasonal Movement of Nutrients in Plants of Differing Growth Form in an Alaskan Tundra Ecosystem: Implications for Herbivory

1980 ◽  
Vol 68 (1) ◽  
pp. 189 ◽  
Author(s):  
F. Stuart Chapin III ◽  
Douglas A. Johnson ◽  
Jay D. McKendrick
Keyword(s):  
Growth Form ◽  
Seasonal Movement ◽  
Tundra Ecosystem ◽  
Alaskan Tundra

Seasonal Changes in Carbon Fractions in Alaskan Tundra Plants of Differing Growth Form: Implications for Herbivory

1986 ◽  
Vol 74 (3) ◽  
pp. 707 ◽  
Author(s):  
F. S. Chapin III ◽  
J. D. McKendrick ◽  
D. A. Johnson
Keyword(s):  
Seasonal Changes ◽  
Growth Form ◽  
Carbon Fractions ◽  
Alaskan Tundra

scholarly journals Mechanistic Modeling of Microtopographic Impacts on CO 2 and CH 4 Fluxes in an Alaskan Tundra Ecosystem Using the CLM‐Microbe Model

2019 ◽  
Vol 11 (12) ◽  
pp. 4288-4304
Author(s):  
Yihui Wang ◽  
Fengming Yuan ◽  
Fenghui Yuan ◽  
Baohua Gu ◽  
Melanie S. Hahn ◽  
...  
Keyword(s):  
Mechanistic Modeling ◽  
Tundra Ecosystem ◽  
Alaskan Tundra

Seasonal diving and foraging behaviour of Eastern Canada-West Greenland bowhead whales

2020 ◽  
Vol 643 ◽  
pp. 197-217 ◽  
Author(s):  
SME Fortune ◽  
SH Ferguson ◽  
AW Trites ◽  
B LeBlanc ◽  
V LeMay ◽  
...  
Keyword(s):  
Climate Change ◽  
Late Summer ◽  
Calanoid Copepods ◽  
Eastern Canada ◽  
West Greenland ◽  
Bowhead Whales ◽  
Seasonal Movement ◽  
Dive Behaviour ◽  
Calanus Glacialis ◽  
Canada West

Climate change may affect the foraging success of bowhead whales Balaena mysticetus by altering the diversity and abundance of zooplankton species available as food. However, assessing climate-induced impacts first requires documenting feeding conditions under current environmental conditions. We collected seasonal movement and dive-behaviour data from 25 Eastern Canada-West Greenland bowheads instrumented with time-depth telemetry tags and used state-space models to examine whale movements and dive behaviours. Zooplankton samples were also collected in Cumberland Sound (CS) to determine species composition and biomass. We found that CS was used seasonally by 14 of the 25 tagged whales. Area-restricted movement was the dominant behaviour in CS, suggesting that the tagged whales allocated considerable time to feeding. Prey sampling data suggested that bowheads were exploiting energy-rich Arctic copepods such as Calanus glacialis and C. hyperboreus during summer. Dive behaviour changed seasonally in CS. Most notably, probable feeding dives were substantially shallower during spring and summer compared to fall and winter. These seasonal changes in dive depths likely reflect changes in the vertical distribution of calanoid copepods, which are known to suspend development and overwinter at depth during fall and winter when availability of their phytoplankton prey is presumed to be lower. Overall, CS appears to be an important year-round foraging habitat for bowheads, but is particularly important during the late summer and fall. Whether CS will remain a reliable feeding area for bowhead whales under climate change is not yet known.

Herbicide Tolerance Of Transgenic `Stevens' Cranberry Plants Depends on the Test Environment

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 517a-517
Author(s):  
Eric L. Zeldin ◽  
Rodney A. Serres ◽  
Brent H. McCown
Keyword(s):  
Growth Form ◽  
Herbicide Tolerance ◽  
Genetically Engineered ◽  
Shoot Tip ◽  
Test Environment ◽  
Growth Environment ◽  
Commercial Formulation ◽  
Tolerance Level ◽  
Delayed Growth ◽  
Significant Injury

`Stevens' cranberry was genetically engineered to confer tolerance to the broad spectrum herbicide glufosinate. Initially, herbicide tolerance was verified by spraying greenhouse plants with the commercial formulation Liberty. Although one transformant showed significant tolerance, the tolerance level was below that required to kill goldenrod, a common weed of cranberry beds. This transformant was propagated and the plants established outdoors in a coldframe, yielding a growth form more typical of field-grown plants than that of greenhouse-grown plants. These plants, as well as untransformed cranberry and goldenrod plants, were sprayed with various levels of the herbicide. The transformed plants were not killed at glufosinate concentrations up to 1000 ppm, although delayed growth did occur. Some runner tip injury was observed at 500 ppm as well as widespread shoot tip death at higher levels. The above-ground parts of goldenrod plants were killed at 400 ppm with significant injury at 200 ppm. Untransformed cranberry plants were killed at 300 ppm and had extensive tip death even at 100 ppm. Transformed cranberry plants with confirmed “field” tolerance were re-established in the greenhouse and new vegetative growth was forced. When these plants were sprayed with glufosinate, significant shoot tip injury was observed at levels as low as 100 ppm. The degree of herbicide tolerance of transformed cranberry appears to be modulated by the growth environment, which may affect the expression of the inserted genes or the physiological sensitivity of the impacted tissues.

Form and Function of Mediterranean Shrublands

2018 ◽  
Author(s):  
Karen J. Esler ◽  
Anna L. Jacobsen ◽  
R. Brandon Pratt
Keyword(s):  
Convergent Evolution ◽  
Growth Form ◽  
Structure And Function ◽  
Adaptive Traits ◽  
Shrub Species ◽  
Leaf Type ◽  
Evergreen Shrub ◽  
Form And Function ◽  
Considerable Research ◽  
And Function

The archetypal shrub type that dominates most of the regions that experience mediterranean-type climate (MTC) is an evergreen shrub with thick and leathery leaves (sclerophyllous). The occurrence of large stands of such shrubs in all MTC regions led early biogeographers to hypothesize that the MTC selects for this growth form and leaf type and that this had led to convergent evolution (see Chapters 1 and 2). This hypothesis has received considerable research interest and continues to be examined. In this chapter we consider the structure and physiology of these archetypal MTC region shrub species and examine evidence for convergent evolution in their structure and function. We also assess the key adaptive traits that enable the shrub species that compose mediterranean-type vegetation (MTV) communities to thrive in MTC regions.

scholarly journals Integrating dark diversity and functional traits to enhance nature conservation of epiphytic lichens: a case study from Northern Italy

2021 ◽  
Author(s):  
Diego Pires Ferraz Trindade ◽  
Meelis Pärtel ◽  
Carlos Pérez Carmona ◽  
Tiina Randlane ◽  
Juri Nascimbene
Keyword(s):  
Climate Change ◽  
Nature Conservation ◽  
Functional Traits ◽  
Growth Form ◽  
Northern Italy ◽  
Epiphytic Lichens ◽  
Mountain Areas ◽  
High Elevations ◽  
Harsh Conditions

AbstractMountains provide a timely opportunity to examine the potential effects of climate change on biodiversity. However, nature conservation in mountain areas have mostly focused on the observed part of biodiversity, not revealing the suitable but absent species—dark diversity. Dark diversity allows calculating the community completeness, indicating whether sites should be restored (low completeness) or conserved (high completeness). Functional traits can be added, showing what groups should be focused on. Here we assessed changes in taxonomic and functional observed and dark diversity of epiphytic lichens along elevational transects in Northern Italy spruce forests. Eight transects (900–1900 m) were selected, resulting in 48 plots and 240 trees, in which lichens were sampled using four quadrats per tree (10 × 50 cm). Dark diversity was estimated based on species co-occurrence (Beals index). We considered functional traits related to growth form, photobiont type and reproductive strategy. Linear and Dirichlet regressions were used to examine changes in taxonomic metrics and functional traits along gradient. Our results showed that all taxonomic metrics increased with elevation and functional traits of lichens differed between observed and dark diversity. At low elevations, due to low completeness and harsh conditions, both restoration and conservation activities are needed, focusing on crustose species. Towards high elevations, conservation is more important to prevent species pool losses, focusing on macrolichens, lichens with Trentepohlia and sexual reproduction. Finally, dark diversity and functional traits provide a novel tool to enhance nature conservation, indicating particular threatened groups, creating windows of opportunities to protect species from both local and regional extinctions.

scholarly journals Within-Site Variability of Liana Wood Anatomical Traits: A Case Study in Laussat, French Guiana

Forests ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 523 ◽  
Author(s):  
Félicien Meunier ◽  
Sruthi M. Krishna Moorthy ◽  
Hannes P. T. De Deurwaerder ◽  
Robin Kreus ◽  
Jan Van den Bulcke ◽  
...  
Keyword(s):  
Specific Gravity ◽  
French Guiana ◽  
Growth Form ◽  
Vessel Diameter ◽  
Small Sample ◽  
Diameter Distribution ◽  
Hydraulic Architecture ◽  
Woody Vines ◽  
Wood Trait ◽  
The Individual

Research Highlights: We investigated the variability of vessel diameter distributions within the liana growth form among liana individuals originating from a single site in Laussat, French Guiana. Background and Objectives: Lianas (woody vines) are key components of tropical forests. Lianas are believed to be strong competitors for water, thanks to their presumed efficient vascular systems. However, unlike tropical trees, lianas are overlooked in field data collection. As a result, lianas are often referred to as a homogeneous growth form while little is known about the hydraulic architecture variation among liana individuals. Materials and Methods: We measured several wood hydraulic and structural traits (e.g., basic specific gravity, vessel area, and vessel diameter distribution) of 22 liana individuals in a single sandy site in Laussat, French Guiana. We compared the liana variability of these wood traits and the correlations among them with an existing liana pantropical dataset and two published datasets of trees originating from different, but species-rich, tropical sites. Results: Liana vessel diameter distribution and density were heterogeneous among individuals: there were two orders of magnitude difference between the smallest (4 µm) and the largest (494 µm) vessel diameters, a 50-fold difference existed between extreme vessel densities ranging from 1.8 to 89.3 vessels mm−2, the mean vessel diameter varied between 26 µm and 271 µm, and the individual theoretical stem hydraulic conductivity estimates ranged between 28 and 1041 kg m−1 s−1 MPa−1. Basic specific gravity varied between 0.26 and 0.61. Consequently, liana wood trait variability, even within a small sample, was comparable in magnitude with tree surveys from other tropical sites and the pantropical liana dataset. Conclusions: This study illustrates that even controlling for site and soil type, liana traits are heterogeneous and cannot be considered as a homogeneous growth form. Our results show that the liana hydraulic architecture heterogeneity across and within sites warrants further investigation in order to categorize lianas into functional groups in the same way as trees

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