Xylem anatomy needs to change, so that conductivity can stay the same: xylem adjustments across elevation and latitude in Nothofagus pumilio

Abstract Background and Aims Plants have the potential to adjust the configuration of their hydraulic system to maintain its function across spatial and temporal gradients. Species with wide environmental niches provide an ideal framework to assess intraspecific xylem adjustments to contrasting climates. We aimed to assess how xylem structure in the widespread species Nothofagus pumilio varies across combined gradients of temperature and moisture, and to what extent within-individual variation contributes to population responses across environmental gradients. Methods We characterized xylem configuration in branches of N. pumilio trees at five sites across an 18° latitudinal gradient in the Chilean Andes, sampling at four elevations per site. We measured vessel area, vessel density and the degree of vessel grouping. We also obtained vessel diameter distributions and estimated the xylem-specific hydraulic conductivity. Xylem traits were studied in the last five growth rings to account for within-individual variation. Key Results Xylem traits responded to changes in temperature and moisture, but also to their combination. Reductions in vessel diameter and increases in vessel density suggested increased safety levels with lower temperatures at higher elevation. Vessel grouping also increased under cold and dry conditions, but changes in vessel diameter distributions across the elevational gradient were site-specific. Interestingly, the estimated xylem-specific hydraulic conductivity remained constant across elevation and latitude, and an overwhelming proportion of the variance of xylem traits was due to within-individual responses to year-to-year climatic fluctuations, rather than to site conditions. Conclusions Despite conspicuous adjustments, xylem traits were coordinated to maintain a constant hydraulic function under a wide range of conditions. This, combined with the within-individual capacity for responding to year-to-year climatic variations, may have the potential to increase forest resilience against future environmental changes.

Download Full-text

Covariation in population trends and demography reveals targets for conservation action

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2020.2955 ◽

2021 ◽

Vol 288 (1946) ◽

pp. 20202955

Author(s):

Catriona A. Morrison ◽

Simon J. Butler ◽

Robert A. Robinson ◽

Jacquie A. Clark ◽

Juan Arizaga ◽

...

Keyword(s):

Large Scale ◽

Environmental Changes ◽

Local Population ◽

Survival Rates ◽

Population Trends ◽

Population Declines ◽

Conservation Action ◽

Local Conditions ◽

Widespread Species ◽

Wide Range

Wildlife conservation policies directed at common and widespread, but declining, species are difficult to design and implement effectively, as multiple environmental changes are likely to contribute to population declines. Conservation actions ultimately aim to influence demographic rates, but targeting actions towards feasible improvements in these is challenging in widespread species with ranges that encompass a wide range of environmental conditions. Across Europe, sharp declines in the abundance of migratory landbirds have driven international calls for action, but actions that could feasibly contribute to population recovery have yet to be identified. Targeted actions to improve conditions on poor-quality sites could be an effective approach, but only if local conditions consistently influence local demography and hence population trends. Using long-term measures of abundance and demography of breeding birds at survey sites across Europe, we show that co-occurring species with differing migration behaviours have similar directions of local population trends and magnitudes of productivity, but not survival rates. Targeted actions to boost local productivity within Europe, alongside large-scale (non-targeted) environmental protection across non-breeding ranges, could therefore help address the urgent need to halt migrant landbird declines. Such demographic routes to recovery are likely to be increasingly needed to address global wildlife declines.

Download Full-text

Paleoenvironments during the Rhaetian transgression and the colonization history of marine biota in the Fatric Unit (Western Carpathians)

Geologica Carpathica ◽

10.2478/geoca-2013-0003 ◽

2013 ◽

Vol 64 (1) ◽

pp. 39-62 ◽

Cited By ~ 4

Author(s):

Jozef Michalík ◽

Otília Lintnerová ◽

Patrycja Wójcik-Tabol ◽

Andrzej Gaździcki ◽

Jacek Grabowski ◽

...

Keyword(s):

Environmental Changes ◽

Rock Magnetism ◽

Arid Environment ◽

Geochemical Data ◽

Hypersaline Lake ◽

Physical Factors ◽

Marine Biota ◽

Bottom Part ◽

Climatic Fluctuations ◽

Wide Range

Abstract Terminal Triassic environmental changes are characterized by an integrated study of lithology, litho- and cyclostratigraphy, paleontology, mineralogy, geochemistry and rock magnetism in the Tatra Mts. The Carpathian Keuper sequence was deposited in an arid environment with only seasonal rivers, temporal lakes and swamps with scarce vegetation. Combination of a wide range of δ18O values (-0.7 to + 2.7) with negative δ13C values documents dolomite precipitation either from brackish or hypersaline lake water, or its derivation from pore water comparably to the Recent Coorong B-dolostone. Negative δ13C values indicate microbial C productivity. Rhaetian transgressive deposits with restricted Rhaetavicula fauna accumulated in nearshore swamps and lagoons. Associations of foraminifers, bivalves and sharks in the Zliechov Basin were controlled by physical factors. Bivalve mollusc biostromes were repetitively destroyed by storms, and temporary firm bottoms were colonized by oysters and burrowers. Subsequent black shale deposition recorded input of eolian dust. Bottom colonization by pachyodont bivalves, brachiopod and corals started much later, during highstand conditions. Facies evolution also revealed by geochemical data, C and O isotope curves reflect eustatic and climatic changes and help reconstruct the evolution of Rhaetian marine carbonate ramp. The Fatra Formation consists of 100 kyr eccentricity and 40 kyr obliquity cycles; much finer rhythmicity may record monsoonlike climatic fluctuations. Fluvial and eolian events were indicated by analysis of grain size and content of clastic quartz, concentrations of foraminiferal (Agathammina) tests in thin laminae indicates marine ingression events. Magnetic susceptibility (MS) variations reflect the distribution of authigenic and detrital constituents in the sequence. Increasing trend of MS correlates with the regressive Carpathian Keuper sequence and culminates within the bottom part of the Fatra Formation. Decreasing trend of MS is observed upwards the transgressive deposits of the Fatra Formation.

Download Full-text

Assessment of the Role of Different Soil Properties on Crust Strength by Linear Regression Models

Journal of AgriSearch ◽

10.21921/jas.v6i04.16895 ◽

2019 ◽

Vol 6 (04) ◽

Author(s):

MINAKSHI SERAWAT ◽

V K PHOGAT ◽

ANIL Abdul KAPOOR ◽

VIJAY KANT SINGH ◽

ASHA SERAWAT

Keyword(s):

Hydraulic Conductivity ◽

Soil Properties ◽

Crop Yields ◽

Modulus Of Rupture ◽

Silty Clay ◽

Linear Regression Models ◽

Wide Range ◽

Dispersion Ratio ◽

Crust Strength

Soil crust strength influences seedling emergence, penetration and morphology of plant roots, and, consequently, crop yields. A study was carried out to assess the role of different soil properties on crust strength atHisar, Haryana, India. The soil samples from 0-5 and 5-15 cm depths were collected from 21 locations from farmer’s fields, having a wide range of texture.Soil propertieswere evaluated in the laboratory and theirinfluence on the modulus of rupture (MOR), which is the measure of crust strength, was evaluated.The MOR of texturally different soils was significantly correlated with saturated hydraulic conductivity at both the depths. Dispersion ratio was found to decrease with an increase in fineness of the texture of soil and the lowest value was recorded in silty clay loam soil,which decreased with depth. The modulus of rupture was significantly negatively correlative with the dispersion ratio.There was no role of calcium carbonate in influencing the values of MOR of soils. Similarly,the influence of pH, EC and SAR of soil solution on MOR was non-significant.A perusal of thevalues of the correlations between MOR and different soil properties showed that the MOR of soils of Haryana are positively correlated with silt + clay (r = 0.805) followed by water-stable aggregates (r = 0.774), organic carbon (r = 0.738), silt (r = 0.711), mean weight diameter (r = 0.608) and clay (r = 0.593) while negatively correlated with dispersion ratio (r = - 0.872), sand (r = -0.801) and hydraulic conductivity (r = -0.752) of soils.

Download Full-text

Predictive modelling of soils’ hydraulic conductivity using artificial neural network and multiple linear regression

SN Applied Sciences ◽

10.1007/s42452-020-03974-7 ◽

2021 ◽

Vol 3 (2) ◽

Author(s):

Charles Gbenga Williams ◽

Oluwapelumi O. Ojuri

Keyword(s):

Neural Network ◽

Artificial Neural Network ◽

Hydraulic Conductivity ◽

Linear Regression ◽

Multiple Linear Regression ◽

Coarse Grained ◽

Soil Types ◽

Wide Range ◽

Artificial Neural ◽

Input Variables

AbstractAs a result of heterogeneity nature of soils and variation in its hydraulic conductivity over several orders of magnitude for various soil types from fine-grained to coarse-grained soils, predictive methods to estimate hydraulic conductivity of soils from properties considered more easily obtainable have now been given an appropriate consideration. This study evaluates the performance of artificial neural network (ANN) being one of the popular computational intelligence techniques in predicting hydraulic conductivity of wide range of soil types and compared with the traditional multiple linear regression (MLR). ANN and MLR models were developed using six input variables. Results revealed that only three input variables were statistically significant in MLR model development. Performance evaluations of the developed models using determination coefficient and mean square error show that the prediction capability of ANN is far better than MLR. In addition, comparative study with available existing models shows that the developed ANN and MLR in this study performed relatively better.

Download Full-text

Cytotype distribution and chloroplast phylogeography of the Actinidia chinensis complex

BMC Plant Biology ◽

10.1186/s12870-021-03099-y ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Zhi Wang ◽

Caihong Zhong ◽

Dawei Li ◽

Chunlin Yan ◽

Xiaohong Yao ◽

...

Keyword(s):

Environmental Changes ◽

Demographic History ◽

Wide Distribution ◽

Historical Demography ◽

Actinidia Chinensis ◽

Ecological Niche Models ◽

Subtropical China ◽

Modeling Tools ◽

Climatic Fluctuations ◽

Ploidy Levels

Abstract Background Plant phylogeographic studies of species in subtropical China have mainly focused on rare and endangered species, whereas few studies have been conducted on taxa with relatively wide distribution, especially polyploid species. We investigated the cytotype and haplotype distribution pattern of the Actinidia chinensis complex, a widespread geographically woody liana with variable ploidy in subtropical China comprising two varieties, with three chloroplast fragments DNA (ndhF-rpl132, rps16-trnQ and trnE-trnT). Macroevolutionary, microevolutionary and niche modeling tools were also combined to disentangle the origin and the demographic history of the species or cytotypes. Results The ploidy levels of 3338 individuals from 128 populations sampled throughout the species distribution range were estimated with flow cytometry. The widespread cytotypes were diploids followed by tetraploids and hexaploids, whereas triploids and octoploids occurred in a few populations. Thirty-one chloroplast haplotypes were detected. The genetic diversity and genetic structure were found to be high between varieties (or ploidy races) chinensis and deliciosa. Our results revealed that these two varieties inhabit significantly different climatic niche spaces. Ecological niche models (ENMs) indicate that all varieties’ ranges contracted during the Last Inter Glacial (LIG), and expanded eastward or northward during the Last Glacial Maximum (LGM). Conclusions Pliocene and Plio-Pleistocene climatic fluctuations and vicariance appear to have played key roles in shaping current population structure and historical demography in the A. chinensis complex. The polyploidization process also appears to have played an important role in the historical demography of the complex through improving their adaptability to environmental changes.

Download Full-text

Identification of Putative Virulence Genes by DNA Methylation Studies in the Cereal Pathogen Fusarium graminearum

Cells ◽

10.3390/cells10051192 ◽

2021 ◽

Vol 10 (5) ◽

pp. 1192

Author(s):

Francesco Tini ◽

Giovanni Beccari ◽

Gianpiero Marconi ◽

Andrea Porceddu ◽

Micheal Sulyok ◽

...

Keyword(s):

Dna Methylation ◽

Fusarium Graminearum ◽

Environmental Changes ◽

Virulent Strain ◽

Fungal Virulence ◽

Wheat Seedlings ◽

Wide Range ◽

Conidia Production ◽

Natural Hosts

DNA methylation mediates organisms’ adaptations to environmental changes in a wide range of species. We investigated if a such a strategy is also adopted by Fusarium graminearum in regulating virulence toward its natural hosts. A virulent strain of this fungus was consecutively sub-cultured for 50 times (once a week) on potato dextrose agar. To assess the effect of subculturing on virulence, wheat seedlings and heads (cv. A416) were inoculated with subcultures (SC) 1, 23, and 50. SC50 was also used to re-infect (three times) wheat heads (SC50×3) to restore virulence. In vitro conidia production, colonies growth and secondary metabolites production were also determined for SC1, SC23, SC50, and SC50×3. Seedling stem base and head assays revealed a virulence decline of all subcultures, whereas virulence was restored in SC50×3. The same trend was observed in conidia production. The DNA isolated from SC50 and SC50×3 was subject to a methylation content-sensitive enzyme and double-digest, restriction-site-associated DNA technique (ddRAD-MCSeEd). DNA methylation analysis indicated 1024 genes, whose methylation levels changed in response to the inoculation on a healthy host after subculturing. Several of these genes are already known to be involved in virulence by functional analysis. These results demonstrate that the physiological shifts following sub-culturing have an impact on genomic DNA methylation levels and suggest that the ddRAD-MCSeEd approach can be an important tool for detecting genes potentially related to fungal virulence.

Download Full-text

Microglial Pruning: Relevance for Synaptic Dysfunction in Multiple Sclerosis and Related Experimental Models

Cells ◽

10.3390/cells10030686 ◽

2021 ◽

Vol 10 (3) ◽

pp. 686

Author(s):

Maria Concetta Geloso ◽

Nadia D’Ambrosi

Keyword(s):

Multiple Sclerosis ◽

Neuronal Death ◽

Environmental Changes ◽

Experimental Models ◽

Synaptic Dysfunction ◽

Synapse Elimination ◽

Neurodegenerative Process ◽

Immune Mediated ◽

Wide Range ◽

Demyelinating Lesions

Microglia, besides being able to react rapidly to a wide range of environmental changes, are also involved in shaping neuronal wiring. Indeed, they actively participate in the modulation of neuronal function by regulating the elimination (or “pruning”) of weaker synapses in both physiologic and pathologic processes. Mounting evidence supports their crucial role in early synaptic loss, which is emerging as a hallmark of several neurodegenerative diseases, including multiple sclerosis (MS) and its preclinical models. MS is an inflammatory, immune-mediated pathology of the white matter in which demyelinating lesions may cause secondary neuronal death. Nevertheless, primitive grey matter (GM) damage is emerging as an important contributor to patients’ long-term disability, since it has been associated with early and progressive cognitive decline (CD), which seriously worsens the quality of life of MS patients. Widespread synapse loss even in the absence of demyelination, axon degeneration and neuronal death has been demonstrated in different GM structures, thus raising the possibility that synaptic dysfunction could be an early and possibly independent event in the neurodegenerative process associated with MS. This review provides an overview of microglial-dependent synapse elimination in the neuroinflammatory process that underlies MS and its experimental models.

Download Full-text

Enhancing the resilience of coupled human and natural systems of alpine rangelands on the Qinghai-Tibetan Plateau

The Rangeland Journal ◽

10.1071/rj14117 ◽

2015 ◽

Vol 37 (1) ◽

pp. i ◽

Cited By ~ 33

Author(s):

Shikui Dong ◽

Ruth Sherman

Keyword(s):

Tibetan Plateau ◽

Science Policy ◽

Sustainable Management ◽

Environmental Changes ◽

Policy Design ◽

Rangeland Management ◽

Special Issue ◽

Natural Systems ◽

Wide Range ◽

Science Policy Interface

This special issue covers a wide range of topics on the protection and sustainable management of alpine rangelands on the Qinghai-Tibetan Plateau (QTP), including Indigenous knowledge of sustainable rangeland management, science-policy interface for alpine rangeland biodiversity conservation, adaptations of local people to social and environmental changes and policy design for managing coupled human-natural systems of alpine rangelands.

Download Full-text

Determinants of valve gating in collecting lymphatic vessels from rat mesentery

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00133.2011 ◽

2011 ◽

Vol 301 (1) ◽

pp. H48-H60 ◽

Cited By ~ 91

Author(s):

Michael J. Davis ◽

Elaheh Rahbar ◽

Anatoliy A. Gashev ◽

David C. Zawieja ◽

James E. Moore

Keyword(s):

Pressure Gradient ◽

Muscle Tone ◽

Lymphatic Vessels ◽

Vessel Diameter ◽

Intraluminal Pressure ◽

Pressure Gradients ◽

Rat Mesentery ◽

Temporal Relationships ◽

Wide Range ◽

Valve Opening

Secondary lymphatic valves are essential for minimizing backflow of lymph and are presumed to gate passively according to the instantaneous trans-valve pressure gradient. We hypothesized that valve gating is also modulated by vessel distention, which could alter leaflet stiffness and coaptation. To test this hypothesis, we devised protocols to measure the small pressure gradients required to open or close lymphatic valves and determine if the gradients varied as a function of vessel diameter. Lymphatic vessels were isolated from rat mesentery, cannulated, and pressurized using a servo-control system. Detection of valve leaflet position simultaneously with diameter and intraluminal pressure changes in two-valve segments revealed the detailed temporal relationships between these parameters during the lymphatic contraction cycle. The timing of valve movements was similar to that of cardiac valves, but only when lymphatic vessel afterload was elevated. The pressure gradients required to open or close a valve were determined in one-valve segments during slow, ramp-wise pressure elevation, either from the input or output side of the valve. Tests were conducted over a wide range of baseline pressures (and thus diameters) in passive vessels as well as in vessels with two levels of imposed tone. Surprisingly, the pressure gradient required for valve closure varied >20-fold (0.1–2.2 cmH2O) as a passive vessel progressively distended. Similarly, the pressure gradient required for valve opening varied sixfold with vessel distention. Finally, our functional evidence supports the concept that lymphatic muscle tone exerts an indirect effect on valve gating.

Download Full-text

The Research and Application of Artificial Intelligence in the Field of Intelligent Robot

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.898.763 ◽

2014 ◽

Vol 898 ◽

pp. 763-766

Author(s):

Zhi Hao Li

Keyword(s):

Artificial Intelligence ◽

Environmental Changes ◽

Vision System ◽

Mineral Exploration ◽

Intelligent Robot ◽

Application Range ◽

Intelligent Robots ◽

External Data ◽

Wide Range ◽

Artificial Intelligence Application

The research and application of artificial intelligence has a very wide range in intelligent robot field. Intelligent robot can not only make use of artificial intelligence gain access to external data, information, (such as stereo vision system, face recognition and tracking, etc.), and then deal with it so as to exactly describe external environment, and complete a task independently, owing the ability of learning knowledge, but also have self-many kinds of artificial intelligence like judgment and decision making, processing capacity and so on. It can make corresponding decision according to environmental changes. Its application range is expanding. In deep sea exploration, star exploration, mineral exploration, heavy pollution, domestic service, entertainment clubs, health care and so on, the figure of intelligent robots artificial intelligence application can all be seen.

Download Full-text