scholarly journals A new mechanistic understanding of ecophysiological patterns in a widespread alpine dwarf shrub – Refining climate-growth relationships

2021 ◽  
Author(s):  
Svenja Dobbert ◽  
Roland Pape ◽  
Jörg Löffler
Keyword(s):  
Thermal Conditions ◽  
Frost Damage ◽  
Growth Patterns ◽  
Environmental Data ◽  
Annual Growth ◽  
Dwarf Shrub ◽  
Environmental Drivers ◽  
Growth Responses ◽  
Evergreen Species ◽  
Early Season

Abstract. Considering the recent widespread greening associated with dwarf shrubs in arctic and alpine ecosystems, further understanding of how these shrubs respond to environmental conditions is of crucial importance. Here we present novel insights and propose a new method to monitor shrub growth, using high-precision point dendrometers. We analyzed intra- and inter-annual growth patterns of a common evergreen species (Empetrum nigrum ssp. hermaphroditum) by measuring its hourly radial stem variability at a micrometer scale over four successive years on exposed ridge positions and along a steep elevational gradient. With the same temporal resolution, we collected near-ground micro-environmental data and identified environmental drivers controlling growth behaviour. Overall, we found high inter-plant variability in growth-defining parameters, but high similarities in growth responses to the micro-environment. Early-season radial growth in spring exhibited high sensitivity to winter thermal conditions and prolonged ground-freezing in spring, suggesting that the evergreen species E. hermaphroditum remains photosynthetically active during the snow-free period, which increases carbohydrate accumulation for early season physiological activities. We discovered a phase of radial stem shrinkage during the winter months, which can be attributed to an active cell water reduction to protect the plant from frost damage. We present the first fine-scale intra-annual growth curves for an alpine dwarf shrub and identify soil moisture availability and winter freezing conditions as the main drivers of radial stem variability, thus forwarding the ongoing debate on the functional mechanisms of greening and browning in arctic and alpine regions.

Dendrometer measurements of arctic-alpine dwarf shrubs and micro-environmental drivers of plant growth - Dataset from long-term alpine ecosystem research in central Norway

Erdkunde ◽  
2021 ◽  
Author(s):  
Jörg Löffler ◽  
Svenja Dobbert ◽  
Roland Pape ◽  
Dirk Wundram
Keyword(s):  
Root Zone ◽  
Monitoring Program ◽  
Growth Patterns ◽  
Environmental Data ◽  
Environmental Drivers ◽  
Horizontal Distance ◽  
Ecosystem Research ◽  
Alpine Ecosystem ◽  
Vegetation Shifts

Here, we present fine-scale measurements of stem diameter variation from three common arctic-alpine dwarf-shrub species monitored in two mountain regions of Central Norway. All three species (Betula nana, Empetrum nigrum ssp. hermaphroditum, and Phyllodoce caerulea) are abundant within the studied regions and highly important contributors to potential future arctic-alpine vegetation shifts. A profound understanding of their radial growth patterns therefore has the potential to yield crucial information regarding climate-growth relations within these ecosystems. We used high-resolution dendrometers (type DRO) to monitor 120 specimens, taking measurements near the shoot base of one major horizontal stem. Along with the shrub growth measurements, we measured on-site micro-environmental data at each studied site, including shoot zone and root zone temperatures as well as soil moisture. All data were recorded at an hourly scale and are presented as daily mean values. The monitoring period spanned five full years (2015 - 2019), with additional data from 2014 and 2020. Data were collected within one of the most continental climate regions of Europe, the Vågå/Innlandet region, and in the oceanic climate region Geiranger/Møre og Romsdal, spanning a steep climate gradient over just ~100 km horizontal distance. Both study regions are characterized by steep elevational gradients and highly heterogeneous micro-topography. The studied sites were chosen to represent these natural conditions using the transect principle. The collection of our original data is subject of our long-term alpine ecosystem monitoring program since 1991, from which numerous publications function as the basis for a recent project on the use of dendrometer data in alpine ecosystem studies.

MARINE BIOGENIC CARBONATES AND RADIOCARBON—A RETROSPECTIVE ON SHELLS AND CORALS WITH AN OUTLOOK ON CHALLENGES AND OPPORTUNITIES

Radiocarbon ◽  
2021 ◽  
pp. 1-16
Author(s):  
Susanne Lindauer ◽  
Carla S Hadden ◽  
Kita Macario ◽  
Thomas P Guilderson
Keyword(s):  
Calcium Carbonate ◽  
Inorganic Carbon ◽  
Dissolved Inorganic Carbon ◽  
Growth Patterns ◽  
Annual Growth ◽  
Environmental Research ◽  
Climate Research ◽  
Marine Carbonates ◽  
Challenges And Opportunities ◽  
Biogenic Carbonates

ABSTRACT Many organisms living in the ocean create tests, shells, or related physical structures of calcium carbonate (CaCO3). As this is most often from dissolved inorganic carbon, using organisms that create calcium carbonate structures for climate research and dating purposes requires knowledge of the origin of carbon that is incorporated. Here, we give a short overview of research on marine carbonates over the last 60 years, especially that based on shell and coral samples. Both shells and corals exhibit annual growth patterns, like trees, and therefore offer possibilities for yearly resolution of past radiocarbon (14C) variations. We concentrate on their evolution in 14C dating including difficulties in determining reservoir ages as well as the possibilities they offer for archaeological dating, oceanography, calibration purposes as well as environmental research in general.

Evaluation of a direct age estimation method for terminally molted male snow crab Chionoecetes opilio (Fabricius 1788) (Decapoda: Brachyura: Oregoniidae)

2020 ◽  
Vol 40 (5) ◽  
pp. 549-555
Author(s):  
April L Rebert ◽  
Gordon H Kruse ◽  
Joel B Webb ◽  
Sherry L Tamone ◽  
Dion Oxman ◽  
...  
Keyword(s):  
Fishery Management ◽  
Estimation Method ◽  
Growth Patterns ◽  
Annual Growth ◽  
Snow Crab ◽  
Gastric Mill ◽  
Age Composition ◽  
Thin Sections ◽  
Chionoecetes Opilio ◽  
Growth Increments

Abstract Recent research suggests that calcified eyestalks and gastric mill ossicles (stomach teeth) can be used to estimate the age of some crustacean species. Along with annual growth of the endocuticle, bipartite bands in the hard tissue are believed to reflect annual growth patterns (similar to fish scales or otoliths) that are retained through repeated molt cycles. Similar bands are observed in the zygocardiac ossicles of the gastric mill from the snow crab (Chionoecetes opilioFabricius 1788). If these bands reflect annual growth, they may be used to estimate age, which could enhance understanding growth, mortality, recruitment, and age composition and improve fishery management. While some studies show that the number of bands correlates to other estimates of age for C. opilio, little evidence suggests that bands accumulate annually as growth increments independent of molting. Male C. opilio terminally molt at maturity, after which they can survive for seven years or more. Shell condition, i.e., degree of wear and epibionts on their exoskeleton, is used here and by other carcinologists as a proxy for age subsequent to the terminal molt. We estimated band counts and endocuticle thickness from thin sections of the zygocardiac ossicle of terminally molted male C. opilio across a range of shell conditions from a wild, fished stock. We found no differences in band counts (P = 0.41) or endocuticle thickness (P = 0.13) across varying shell conditions and size. These results do not support the hypothesis that band counts can be used to estimate the age of this species after the terminal molt.

Example of the Effects of Early Season Frost Damage on Yield of Corn

Crop Science ◽  
1973 ◽  
Vol 13 (6) ◽  
pp. 760-761 ◽  
Author(s):  
D. C. Arny ◽  
C. D. Upper
Keyword(s):  
Frost Damage ◽  
Early Season

Growth performance of Alexandrium catenella from the Chilean fjords under different environmental drivers: plasticity as a response to a highly variable environment

2020 ◽  
Vol 42 (2) ◽  
pp. 119-134 ◽  
Author(s):  
Javier Paredes-Mella ◽  
Daniel Varela ◽  
Pamela Fernández ◽  
Oscar Espinoza-González
Keyword(s):  
Light Intensity ◽  
Growth Performance ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Optimal Growth ◽  
N:P Ratio ◽  
Environmental Drivers ◽  
Growth Responses ◽  
Variable Environment ◽  
Alexandrium Catenella

Abstract Alexandrium catenella, the main species associated with harmful algal blooms, has progressively increased its distribution through one of the most extensive and highly variable fjord systems in the world. In order to understand this successful expansion, we evaluated the effects of different salinities, light intensity, temperatures, nitrogen (N) forms and nitrogen/phosphate (N:P) ratio levels on the growth performance, using clones isolated from different locations across its wide geographic distribution. Results showed that the growth responses were plastic and, in some cases, different reaction norms among clones were observed. Despite plasticity, the optimal growth of A. catenella (i.e. highest growth rate and highest maximal cells density) was reached within a narrow thermal range (12–15°C), while salinity (20–30 PSU) and light intensity (20–120 μmol m−2 s−1) ranges were wider. These results are partially consistent with the highest cell densities recorded in the field. Furthermore, optimal growth was reached using reduced forms of nitrogen (i.e. urea and NH4+) and in unbalanced N:P ratios (18:1 and 30:1). These characteristics likely allow A. catenella to grow in highly variable environmental conditions and might partly explain the recent expansion of this species.

scholarly journals Improvement of Remote Sensing-Based Assessment of Defoliation of Pinus spp. Caused by Thaumetopoea Pityocampa Denis and Schiffermüller and Related Environmental Drivers in Southeastern Spain

2019 ◽  
Vol 11 (14) ◽  
pp. 1736 ◽  
Author(s):  
Pérez-Romero ◽  
Navarro-Cerrillo ◽  
Palacios-Rodriguez ◽  
Acosta ◽  
Mesas-Carrascosa
Keyword(s):  
Remote Sensing ◽  
Google Earth ◽  
Environmental Data ◽  
Environmental Drivers ◽  
Series Data ◽  
Model Parameters ◽  
Summer Drought ◽  
Southeastern Spain ◽  
Pinus Species ◽  
Pinus Spp

This study used Landsat temporal series to describe defoliation levels due to the Pine Processionary Moth (PPM) in Pinus forests of southeastern Andalusia (Spain), utilizing Google Earth Engine. A combination of remotely sensed data and field survey data was used to detect the defoliation levels of different Pinus spp. and the main environmental drivers of the defoliation due to the PPM. Four vegetation indexes were also calculated for remote sensing defoliation assessment, both inside the stand and in a 60-m buffer area. In the area of study, all Pinus species are affected by defoliation due to the PPM, with a cyclic behavior that has been increasing in frequency in recent years. Defoliation levels were practically equal for all species, with a high increase in defoliation levels 2 and 3 since 2014. The Moisture Stress Index (MSI) and Normalized Difference Infrared Index (NDII) exhibited similar overall (P < 0.001) accuracy in the assessment of defoliation due to the PPM. The synchronization of NDII-defoliation data had a similar pattern for all together and individual Pinus species, showing the ability of this index to adjust the model parameters based on the characteristics of specific defoliation levels. Using Landsat-based NDII-defoliation maps and interpolated environmental data, we have shown that the PPM defoliation in southeastern Spain is driven by the minimum temperature in February and the precipitation in June, March, September, and October. Therefore, the NDII-defoliation assessment seems to be a general index that can be applied to forests in other areas. The trends of NDII-defoliation related to environmental variables showed the importance of summer drought stress in the expansion of the PPM on Mediterranean Pinus species. Our results confirm the potential of Landsat time-series data in the assessment of PPM defoliation and the spatiotemporal patterns of the PPM; hence, these data are a powerful tool that can be used to develop a fully operational system for the monitoring of insect damage.

Climatic signal in annual growth variation of Norway spruce (Picea abies) along a transect from central Finland to the Arctic timberline

2000 ◽  
Vol 30 (5) ◽  
pp. 769-777 ◽  
Author(s):  
Harri Mäkinen ◽  
Pekka Nöjd ◽  
Kari Mielikäinen
Keyword(s):  
Picea Abies ◽  
Norway Spruce ◽  
Ring Width ◽  
Growth Patterns ◽  
The Arctic ◽  
Strongly Correlated ◽  
Growth Responses ◽  
Geographical Differences ◽  
Growth Variation ◽  
Temperature And Growth

Regional and temporal growth patterns of Norway spruce (Picea abies (L.) Karst.) were evaluated in 40 stands along a transect of over 500 km running from central Finland to the Arctic spruce timberline. Standard deviation of the ring-width series increased from south to north, but the geographical differences in mean sensitivity and first-order autocorrelation were small. The high degree of similarity in growth variation between stands indicated similar growth responses of trees to weather variation despite different environmental conditions along the transect. The most pronounced differences in the regional increment chronologies were found between the southernmost and northernmost stands. Growth variation was most strongly correlated with current June mean temperature, and correlation between growth and July temperature increased from south to north. In addition, negative correlation was observed between winter temperatures, particularly February temperature, and growth variation. Growth was more weakly correlated with precipitation than with temperature.

GROWTH RESPONSES OF SCOTS PINE (PINACEAE) TO ARTIFICIAL AND SAWFLY (HYMENOPTERA: DIPRIONIDAE) DEFOLIATION

1999 ◽  
Vol 131 (4) ◽  
pp. 455-463 ◽  
Author(s):  
Päivi Lyytikäinen-Saarenmaa
Keyword(s):  
Scots Pine ◽  
First Year ◽  
Growth Responses ◽  
Early Season ◽  
Late Season ◽  
Plant Parts ◽  
Biomass Loss ◽  
Growth Loss ◽  
Growth Differences ◽  
The Impact

AbstractThe influence of defoliation type (artificial versus natural), timing (early versus late), and intensity (25%, 50%, and 75% of needle mass removed) on leader growth of Scots pine, Pinus sylvestris (Linnaeus), was assessed for 2 years after treatment on an even-aged stand located in southeastern Finland. Trees were defoliated simultaneously, either artificially with a pair of scissors or naturally with larvae of Neodiprion sertifer (Geoffroy) and Diprion pini (Linnaeus) for the early- and late-season treatments, respectively. After 1 year, early-season artificial defoliation generally caused greater growth reduction than natural defoliation. Late-season defoliation yielded opposite results. Trees defoliated artificially in early-season treatments were significantly shorter than control trees irrespective of defoliation intensity, whereas those defoliated late in the season did not differ from controls, except at the highest intensity. Trees defoliated by sawflies, either early or late in the season, were significantly shorter than control trees only at the highest defoliation intensity. The pattern of growth loss in the second year appeared similar to that in the first year. The impact of defoliation was either prolonged neutral or negative, as no compensatory responses on height growth in Scots pine were observed. Timing of the treatment in relation to completion of leader growth, differences in defoliation types, alteration of the photosynthetic capacity due to biomass loss, and the functional role of plant parts defoliated may explain the results observed.

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