Tree-growth at the rear edge of a Nothofagus pumilio Andean forest from Northern Patagonia show different patterns and a decline in the common signal during the last century

2020 ◽  
Vol 475 ◽  
pp. 118426
Author(s):  
Hernán Serrano-León ◽  
Duncan A. Christie
Keyword(s):  
Tree Growth ◽  
Nothofagus Pumilio ◽  
Rear Edge ◽  
Northern Patagonia ◽  
The Common ◽  
Common Signal

Euclid and the art of wavelet estimation, Part II: Robust algorithm and field‐data examples

Geophysics ◽  
1997 ◽  
Vol 62 (6) ◽  
pp. 1939-1946 ◽  
Author(s):  
Eike Rietsch
Keyword(s):  
Field Data ◽  
Synthetic Data ◽  
Noise Resistance ◽  
Zero Eigenvalue ◽  
Seismic Line ◽  
Robust Algorithm ◽  
Seismic Wavelet ◽  
Time Zones ◽  
The Common ◽  
Common Signal

In this second part of a two‐part work, a more robust algorithm is derived and used for the estimation of the seismic wavelet as the common signal of two or more seismic traces. It is based on the properties of the eigenvectors with zero eigenvalue of a matrix derived in the first part, whose elements are the samples of the autocorrelation functions and crosscorrelation functions of these seismic traces for a number of lags. The noise resistance of this algorithm is illustrated by means of a synthetic‐data example and then demonstrated on field data. In one field‐data example, the so‐called Euclid wavelet is compared with one derived deterministically by means of an impedance log. The other example relates three quite different Euclid wavelets determined in three different time zones on a seismic line to one another by showing that their differences can be explained by absorption.

Tectonic influences on tree growth in northern Patagonia, Argentina: the roles of substrate stability and climatic variation

1995 ◽  
Vol 25 (10) ◽  
pp. 1684-1696 ◽  
Author(s):  
Thomas Kitzberger ◽  
Thomas T. Veblen ◽  
Ricardo Villalba
Keyword(s):  
Tree Ring ◽  
Tree Growth ◽  
Tree Mortality ◽  
Synergistic Effects ◽  
Climatic Variation ◽  
Growth Patterns ◽  
Great Earthquake ◽  
Northern Patagonia ◽  
South Central ◽  
Substrate Stability

In northern Patagonia, Argentina, we examined the influences of climatic variation and inter-site variation in substrate stability on the dendroecological effects of earthquakes. In association with the great earthquake in 1960 centered off the coast of nearby Valdivia, Chile, extensive tree mortality occurred in northern Patagonia in Nothofagusdombeyi–Austrocedruschilensis stands on unstable debris fans. To examine the effects of the 1960 and earlier earthquakes on tree growth, we developed tree-ring chronologies from samples of the surviving A. chilensis on unstable debris fan sites and at adjacent nonfan sites of more stable substrates. For controlling the effects of regional climatic variation, we also produced a tree-ring chronology from this species in a more distant and undisturbed stand. Strong variations in tree-growth patterns on fan sites were associated with the historically documented major seismic events of south central Chile that occurred in 1737, 1751, 1837, and 1960. Tree-ring chronologies from nonfan sites (i.e., sites of greater substrate stability) showed much less response to these earthquakes. On the fan sites, strong growth suppressions were associated with the former three earthquakes, whereas strong releases followed the 1960 earthquake. The difference in response is explained by the occurrence of the 1960 earthquake during a period of drought, which in combination with the violent shaking of the ground, resulted in extensive tree mortality followed by growth releases of the survivors. However, severe droughts in the absence of earthquakes also can produce tree mortality and subsequent release of the survivors. Consequently, the synergistic effects of climatic variation and earthquake events must be carefully considered in developing records of both climatic variation and earthquakes.

scholarly journals Mechanical harvesting of plums for processing with a continuously moving combine harvester

2012 ◽  
Vol 20 (1) ◽  
pp. 29-42 ◽  
Author(s):  
Augustyn Mika ◽  
Paweł Wawrzyńzak ◽  
Zbigniew Buler ◽  
Dorota Konopacka ◽  
Paweł Konopacki ◽  
...  
Keyword(s):  
Tree Growth ◽  
Training System ◽  
The Self ◽  
Prunus Domestica ◽  
Bud Formation ◽  
The Third ◽  
Combine Harvester ◽  
The Common ◽  
Training And Pruning

ABSTRACT Eleven plum cultivars (Prunus domestica L.) for processing grafted on semidwarf rootstock ‘Wangenheim Prune’ and vigorous rootstock ‘Myrobalan’ were densely planted (1000, 1250, 1666, 2500 trees ha-1) and trained to central leader spindle tree. A new training system was applied to obtain trees suitable for mechanical harvesting. The leader was not headed after planting and summer training procedures were performed in May/June. From the third year onwards, renewal pruning was carried out after fruit harvesting. The new training and pruning systems resulted in very fast tree growth, abundant branching, fruit bud formation on young wood and early bearing. The plum trees appeared to be suitable for hand and mechanical harvesting within 3 years from planting. The self propelled straddle combine harvester was able to harvest 2-3 tons of plums per hour compared to 30 kg with hand picking. Harvesting effectiveness was 90-95%. The quality of mechanically harvested plums was a little worse than of those hand picked, but fruits were suitable for processing. The ‘Common Prune’ and the prune type small plums were the most suitable fruit for mechanical harvesting.

scholarly journals Modulated oscillations in many dimensions

2013 ◽  
Vol 371 (1984) ◽  
pp. 20110551 ◽  
Author(s):  
S. C. Olhede
Keyword(s):  
Physical Oceanography ◽  
Time Varying ◽  
Signal Component ◽  
One Dimensional ◽  
The Common ◽  
The Difference ◽  
Common Signal ◽  
Multivariate Signals ◽  
Special Case ◽  
Signal Models

Modulated oscillations are described via their time-varying amplitude and frequency. For multivariate signals, there is structure in the signal beyond this local amplitude and frequency defined for each signal component, in turn describing the commonality of the components. The multivariate structure encodes how the common oscillation is present in each component signal. This structure will also be evolving. I review the special case of the representation of both bivariate and trivariate oscillations. Additionally, existing results on the general multivariate oscillation are covered. I discuss the difference between a model of a multivariate oscillation compared with other common signal models of phenomena observed in several channels, and how their properties are different. I show how for the multivariate signal the global dimensionality of the signal is built up from local one-dimensional contributions, and introduce the purely unidirectional signal, to quantify how any given signal is different from the closest such signal. I illustrate the properties of the derived representation of the multivariate signal with synthetic examples, and discuss the representation of data from observations in physical oceanography.

scholarly journals Nothofagus pumilio forest affected by recent tephra deposition in northern Patagonia. I- Environmental traits influencing seedling growth

2018 ◽  
pp. 0-0
Author(s):  
Denise. Moguilevsky ◽  
Natalia V. Fernández ◽  
Pablo E. Cornejo ◽  
Javier G. Puntieri ◽  
Sonia B. Fontenla
Keyword(s):  
Seedling Growth ◽  
Nothofagus Pumilio ◽  
Northern Patagonia

scholarly journals Ecology, molecules and colour: Multivariate species delimitation and conservation of Harlequin poison frogs

2016 ◽  
Author(s):  
Andres Posso-Terranova ◽  
Jose A. Andres
Keyword(s):  
Amplicon Sequencing ◽  
Gene Exchange ◽  
Multivariate Statistical Techniques ◽  
Isolated Populations ◽  
Multivariate Statistical ◽  
Poison Frogs ◽  
Genomic Complexity ◽  
The Common ◽  
Study Case ◽  
Common Signal

AbstractWe propose a iterative protocol for delimiting species under the generalized lineage concept (GLC) based on the multivariate clustering of morphological, ecological, and genetic data. Our rationale is that the resulting groups should correspond to evolutionarily independent metapopulation lineages because they reflect the common signal of different secondary defining properties (ecological and genetic distinctiveness, morphological diagnosability, etc.), implying the existence of barriers preventing or limiting gene exchange. We applied this method to study a group of highly endangered poison frogs, the Oophaga histrionica complex. In our study case, we use next generation targeted amplicon sequencing to obtain a robust genetic dataset that we then combined with patterns of morphological and ecological divergence. Our analyses revealed the existence of at least five different species in the histrionica complex (three of them new to science) occurring in very small isolated populations outside any protected areas. More broadly, our study exemplifies how transcriptome-based reduction of genomic complexity and multivariate statistical techniques can be integrated to successfully identify species and their boundaries.In memoriam“I propose that each species has a distinctive life history, which include a series of stages that correspond to some of the named species concepts”Richard G. Harrison1945-2016

scholarly journals A unified framework for dissecting the effects of common signals on functional and effective connectivity analyses: power, coherence, and Granger causality

2017 ◽  
Author(s):  
Dror Cohen ◽  
Naotsugu Tsuchiya
Keyword(s):  
Granger Causality ◽  
Effective Connectivity ◽  
Reference Electrode ◽  
Mathematical Framework ◽  
Connectivity Analysis ◽  
Unified Framework ◽  
Special Cases ◽  
Recorded Data ◽  
The Common ◽  
Common Signal

AbstractWhen analyzing neural data it is important to consider the limitations of the particular experimental setup. An enduring issue in the context of electrophysiology is the presence of common signals. For example a non-silent reference electrode adds a common signal across all recorded data and this adversely affects functional and effective connectivity analysis. To address the common signals problem, a number of methods have been proposed, but relatively few detailed investigations have been carried out. We address this gap by analyzing local field potentials recorded from the small brains of fruit flies. We conduct our analysis following a solid mathematical framework that allows us to make precise predictions regarding the nature of the common signals. We demonstrate how a framework that jointly analyzes power, coherence and quantities from the Granger causality framework allows us to detect and assess the nature of the common signals. Our analysis revealed substantial common signals in our data, in part due to a non-silent reference electrode. We further show that subtracting spatially adjacent signals (bipolar rereferencing) largely removes the effects of the common signals. However, in some special cases this operation itself introduces a common signal. The mathematical framework and analysis pipeline we present can readily be used by others to detect and assess the nature of the common signals in their data, thereby reducing the chance of misinterpreting the results of functional and effective connectivity analysis.

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