scholarly journals Relative changes of resource use efficiencies and their responses to environmental factors in Artemisia ordosica during growing season

2019 ◽  
Vol 43 (10) ◽  
pp. 889-898
Author(s):  
Xin-Hao LI ◽  
Hui-Juan YAN ◽  
Teng-Zhou WEI ◽  
Wen-Jun ZHOU ◽  
Xin JIA ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Resource Use ◽  
Growing Season ◽  
Artemisia Ordosica

scholarly journals Constraint of soil moisture on CO<sub>2</sub> efflux from tundra lichen, moss, and tussock in Council, Alaska, using a hierarchical Bayesian model

2014 ◽  
Vol 11 (19) ◽  
pp. 5567-5579 ◽  
Author(s):  
Y. Kim ◽  
K. Nishina ◽  
N. Chae ◽  
S. J. Park ◽  
Y. J. Yoon ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Environmental Factors ◽  
Soil Temperature ◽  
Co2 Emission ◽  
Emission Rate ◽  
Growing Season ◽  
The Arctic ◽  
Co2 Efflux ◽  
Growing Seasons ◽  
Tundra Ecosystem

Abstract. The tundra ecosystem is quite vulnerable to drastic climate change in the Arctic, and the quantification of carbon dynamics is of significant importance regarding thawing permafrost, changes to the snow-covered period and snow and shrub community extent, and the decline of sea ice in the Arctic. Here, CO2 efflux measurements using a manual chamber system within a 40 m × 40 m (5 m interval; 81 total points) plot were conducted within dominant tundra vegetation on the Seward Peninsula of Alaska, during the growing seasons of 2011 and 2012, for the assessment of driving parameters of CO2 efflux. We applied a hierarchical Bayesian (HB) model – a function of soil temperature, soil moisture, vegetation type, and thaw depth – to quantify the effects of environmental factors on CO2 efflux and to estimate growing season CO2 emissions. Our results showed that average CO2 efflux in 2011 was 1.4 times higher than in 2012, resulting from the distinct difference in soil moisture between the 2 years. Tussock-dominated CO2 efflux is 1.4 to 2.3 times higher than those measured in lichen and moss communities, revealing tussock as a significant CO2 source in the Arctic, with a wide area distribution on the circumpolar scale. CO2 efflux followed soil temperature nearly exponentially from both the observed data and the posterior medians of the HB model. This reveals that soil temperature regulates the seasonal variation of CO2 efflux and that soil moisture contributes to the interannual variation of CO2 efflux for the two growing seasons in question. Obvious changes in soil moisture during the growing seasons of 2011 and 2012 resulted in an explicit difference between CO2 effluxes – 742 and 539 g CO2 m−2 period−1 for 2011 and 2012, respectively, suggesting the 2012 CO2 emission rate was reduced to 27% (95% credible interval: 17–36%) of the 2011 emission, due to higher soil moisture from severe rain. The estimated growing season CO2 emission rate ranged from 0.86 Mg CO2 in 2012 to 1.20 Mg CO2 in 2011 within a 40 m × 40 m plot, corresponding to 86 and 80% of annual CO2 emission rates within the western Alaska tundra ecosystem, estimated from the temperature dependence of CO2 efflux. Therefore, this HB model can be readily applied to observed CO2 efflux, as it demands only four environmental factors and can also be effective for quantitatively assessing the driving parameters of CO2 efflux.

scholarly journals Responses of pea (Pisum sativum L.) to the rising atmospheric concentration of carbon-dioxide

2017 ◽  
pp. 185-188
Author(s):  
András Tamás ◽  
Ágnes Törő ◽  
Tamás Rátonyi ◽  
Endre Harsányi
Keyword(s):  
Carbon Dioxide ◽  
Environmental Factors ◽  
Atmospheric Carbon Dioxide ◽  
Photosynthetic Apparatus ◽  
Carbon Dioxide Concentration ◽  
Growing Season ◽  
Atmospheric Concentration ◽  
Pisum Sativum L ◽  
Key Factor ◽  
Carbon Dioxide Levels

The atmospheric concentration of carbon dioxide increases from decade to decade in increasing pace. In 1957, atmospheric carbon dioxide levels were around 315 ppm, while in 2012 it amounted to 394.49 ppm concentration. In parallel, the global temperature is rising,which is projected to average 1.5–4.5 °C. The carbon dioxide concentration is a key factor – in interaction with the light – affects the plant's photosynthesis. Among the various factors significant interactions prevail: environmental factors affect - the growth and the development of plants, leaf area size and composition, the function of the photosynthetic apparatus, the duration of growing season.

scholarly journals Rainfall in growing season determines the size of an annual-dominated soil seed bank in a desert ecosystem

2020 ◽  
Author(s):  
Ya-Fei Shi ◽  
Zengru Wang ◽  
Bing-Xin Xu ◽  
Jian-Qiang Huo ◽  
Rui Hu ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Species Composition ◽  
Seed Bank ◽  
Soil Seed Bank ◽  
Growing Season ◽  
Seed Banks ◽  
Desert Ecosystem ◽  
Perennial Herb ◽  
Desert Ecosystems ◽  
Soil Seed Banks

Soil seed banks may offer great potential for restoring and maintaining desert ecosystems that have been degraded by climate change and anthropogenic disturbance. However, few studies have explored the annual dynamics in the composition and relative abundance of these soil seed banks. We conducted a long-term observational study to assess the effects of environmental factors (meteorology and microtopography) and aboveground vegetation on the soil seed bank of the Tengger Desert, China. The desert seed bank was dominated by annual herbs. We found that more rainfall in the growing season increased the number of seeds in the soil seed bank, and that quadrats at relatively higher elevations had fewer seeds. The species composition had more similarity in the seed bank than in the aboveground vegetation, though the seed bank and aboveground vegetation did change synchronously due to the rapid propagation of annuals. Together, our findings suggest that the combined effects of environmental factors and plant life forms determine the species composition and size of soil seed banks in deserts. Thus, if degraded desert ecosystems are left to regenerate naturally, the lack of shrub and perennial herb seeds could crucially limit their restoration. Human intervention and management may have to be applied to enhance the seed abundance of longer-lived lifeforms in degraded deserts.

Gigantism in tadpoles of the Neogene frogPalaeobatrachus

Paleobiology ◽  
2006 ◽  
Vol 32 (4) ◽  
pp. 666-675 ◽  
Author(s):  
Zbyněk Roček ◽  
Ronald Böttcher ◽  
Richard Wassersug
Keyword(s):  
Thyroid Gland ◽  
Environmental Factors ◽  
Growing Season ◽  
Tropical Species ◽  
Large Size ◽  
Ecological Features ◽  
Pathological Conditions ◽  
Seasonal Ponds ◽  
Pond Size ◽  
Pseudis Paradoxa

We describe three giant palaeobatrachid fossil tadpoles of the genusPalaeobatrachus(Nieuwkoop-Faber [NF] stages 60–64) from the Miocene of Randecker Maar, Germany. The largest was 150 mm at the beginning of metamorphosis (stage 60), whereas the smallest was 100 mm and approaching the end of metamorphosis (stage 64). In contrast, normal palaeobatrachid tadpoles and their pipid relatives, both extinct and extant, rarely exceed 60 mm in length. We review here both ecological and pathological conditions that are conducive to the development of gigantism in tadpoles. Tadpoles that lack a thyroid gland become exceptionally large and arrest development at early hindlimb stages (NF stages 53–56). However, the advanced metamorphic stages of the giantPalaeobatrachustadpoles indicate that they were able to metamorphose, and thus were not athyroid. Environmental factors—pond size and permanence, predators, duration of the growing season—may all contribute to tadpole gigantism in certain extant anuran species. We identify suites of ecological features that distinguish extant anurans with large tadpoles from high-latitude and high-altitude permanent lakes in temperate regions (e.g., certainRanaandTelmatobius) from tropical species, such asPseudis paradoxa, whose tadpoles normally achieve large size in temporary seasonal ponds. The paleoecology of Randecker Maar suggests thatPalaeobatrachustadpoles lived in a permanent semitropical lake, but one with few predators.

The relative importance of environmental factors on the interannual variability of carbon fluxes in the boreal forest

2020 ◽  
Author(s):  
Mariam El-Amine ◽  
Alexandre Roy ◽  
Pierre Legendre ◽  
Oliver Sonnentag
Keyword(s):  
Environmental Factors ◽  
Boreal Forest ◽  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Carbon Sink ◽  
Growing Season ◽  
Carbon Uptake ◽  
Net Ecosystem Productivity ◽  
Ecosystem Productivity ◽  
Environmental Controls

&lt;p&gt;As climate change will cause a more pronounced rise of air temperature in northern high latitudes than in other parts of the world, it is expected that the strength of the boreal forest carbon sink will be altered. To better understand and quantify these changes, we studied the influence of different environmental controls (e.g., air and soil temperatures, soil water content, photosynthetically active radiation, normalized difference vegetation index) on the timing of the start and end of the boreal forest growing season and the net carbon uptake period in Canada. The influence of these factors on the growing season carbon exchanges between the atmosphere and the boreal forest were also evaluated. There is a need to improve the understanding of the role of the length of the growing season and the net carbon uptake period on the strength of the boreal forest carbon sink, as an extension of these periods might not necessarily result in a stronger carbon sink if other environmental factors are not optimal for carbon sequestration or enhance respiration.&lt;/p&gt;&lt;p&gt;Here, we used 31 site-years of observation over three Canadian boreal forest stands: Eastern, Northern and Southern Old Black Spruce in Qu&amp;#233;bec, Manitoba and Saskatchewan, respectively. Redundancy analyses were used to highlight the environmental controls that correlate the most with the annual net ecosystem productivity and the start and end of the growing season and the net carbon uptake period. Preliminary results show that the timing at which the air temperature becomes positive correlates the most strongly with the start of the net carbon uptake period (r = 0.70, p &lt; 0.001) and the start of the growing season (r = 0.55, p &lt; 0.01). Although the increase of the normalized difference vegetation index also correlates with the start of these periods, a thorough examination of this result shows that the latter happens well before the former. No dependency between any environmental control and the end of the net carbon uptake period was identified. Also, the annual net ecosystem productivity is highly correlated with the length of the net carbon uptake period (r = 0.54, p &lt; 0.01). Other environmental controls such as annual precipitations, the mean annual soil temperature or the maximum yearly normalized difference vegetation index have a smaller impact on the annual net ecosystem productivity. By extending the dataset to include forest stands that represent a wider climate and permafrost variability, we will examine the generalizability of these results.&lt;/p&gt;

scholarly journals Functional composition and diversity of leaf traits in subalpine versus alpine vegetation in the Apennines

AoB Plants ◽  
2020 ◽  
Vol 12 (2) ◽  
Author(s):  
Angela Stanisci ◽  
Alessandro Bricca ◽  
Valentina Calabrese ◽  
Maurizio Cutini ◽  
Harald Pauli ◽  
...  
Keyword(s):  
Functional Diversity ◽  
Functional Traits ◽  
Resource Use ◽  
Leaf Traits ◽  
Growing Season ◽  
Plant Functional Traits ◽  
High Mountain ◽  
Maximum Height ◽  
Dry Matter Content ◽  
Functional Composition

Abstract Mediterranean high mountain grasslands are shaped by climatic stress and understanding their functional adaptations can contribute to better understanding ecosystems’ response to global change. The present work analyses the plant functional traits of high-elevation grasslands growing in Mediterranean limestone mountains to explore, at the community level, the presence of different plant strategies for resource use (conservative vs. acquisitive) and functional diversity syndromes (convergent or divergent). Thus, we compared the functional composition and diversity of the above-ground traits related to resource acquisition strategies of subalpine and alpine calcareous grasslands in the central Apennines, a mountain region characterized by a dry-summer Mediterranean climate. We used georeferenced vegetation plots and field-measured plant functional traits (plant maximum height, specific leaf area and leaf dry matter content) for the dominant species of two characteristic vegetation types: the subalpine Sesleria juncifolia community and the alpine Silene acaulis community. Both communities are of particular conservation concern and are rich in endemic species for which plant functional traits are measured here for the first time. We analysed the functional composition and diversity using the community-weighted mean trait index and the functional diversity using Rao’s function, and we assessed how much the observed pattern deviated from a random distribution by calculating the respective standardized effect sizes. The results highlighted that an acquisitive resource use strategy and relatively higher functional diversity of leaf traits prevail in the alpine S. acaulis community, optimizing a rapid carbon gain, which would help overcome the constraints exerted by the short growing season. The divergent functional strategy underlines the co-occurrence of different leaf traits in the alpine grasslands, which shows good adaptation to a microhabitat-rich environment. Conversely, in the subalpine S. juncifolia grassland, a conservative resource use strategy and relatively lower functional diversity of the leaf traits are likely related to a high level resistance to aridity over a longer growing season. Our outcomes indicate the preadaptation strategy of the subalpine S. juncifolia grassland to shift upwards to the alpine zone that will become warmer and drier as a result of anthropogenic climate change.

scholarly journals Modeling Canopy Carbon and Water Fluxes Using a Multilayered Model over a Temperate Meadow in Inner Mongolia

2019 ◽  
Vol 14 (1) ◽  
pp. 141-154
Author(s):  
Nina Chen ◽  
Anzhi Wang ◽  
Juan An ◽  
Yushu Zhang ◽  
Ruipeng Ji ◽  
...  
Keyword(s):  
Stomatal Conductance ◽  
Environmental Factors ◽  
Vapor Pressure ◽  
Inner Mongolia ◽  
Saturated Vapor ◽  
Water Flux ◽  
Growing Season ◽  
Leaf Nitrogen ◽  
Leaf Nitrogen Content ◽  
Vegetation Characteristic

Abstract To incorporate canopy vertical structure in a process-based model over a temperate meadow, a multilayered model estimated canopy carbon flux (Fc) and water flux (LE) was applied by comparing with eddy covariance measurements in Inner Mongolia, China. Simulations of diurnal, seasonal CO2 and H2O fluxes and model sensitivity to parameters and variables were analyzed. The results showed that the model underestimated Fc and LE by about 0.6% and 5.0%, respectively. It was able to simulate the diurnal and seasonal variation of Fc and LE and performed well during the day and in the growing season, but poorly at night and early in the growing season. Fc was more sensitive to the leaf nitrogen content distribution coefficient and maximum catalytic activity of Rubisco, whereas LE showed greater sensitivity to the stomatal conductance parameter a1, empirical coefficient of stomatal response to saturated vapor pressure difference Vpds0, and minimum stomatal conductance of CO2gsc0. The response of Fc to environmental factors was ranked as air CO2 concentration (Ca) > air temperature (Ta) > photosynthetically active radiation (PAR) > soil water content (θsm) > vapor pressure deficit (VPD) > wind speed (u0). The response of LE to environmental factors was ranked as Ta > VPD > θsm> PAR> Ca> u0. The response of LE to vegetation characteristic parameters was greater than that of Fc.

scholarly journals Pengaruh Pemberian CO2 terhadap pH Air pada Pertumbuhan Caulerpa racemosa var. uvifera

2018 ◽  
Vol 21 (1) ◽  
pp. 17
Author(s):  
Nor Sa'adah ◽  
Sekar Widyaningsih
Keyword(s):  
Water Quality ◽  
Growth Rate ◽  
Environmental Factors ◽  
Specific Growth ◽  
Growing Season ◽  
Caulerpa Racemosa ◽  
Water Media ◽  
Water Ph ◽  
Wet Weight ◽  
The Impact

Abstract The Effect of CO2 on Water pH to Caulerpa racemosa var. uvifera GrowthAlthough in the growing season, seaweed type Caulerpa racemosa var. uvifera sometimes has not be found in the field due to environmental factors. So seaweed mariculture is urgently needed. This research was aimed to study the impact of  providing CO2 with different duration in the water media on the growth of C. racemosa var. uvifera. This research was used 5 treatments with 3 repetitions, namely: A (without CO2 as a control), B (providing CO2 for 6 hours per day), C (giving CO2 for 12 minutes per day), D (CO2 delivery, 18 minutes per day) and E (providing CO2 for 24 minutes per day). The observed data in the form of wet weight and water quality that were used as maintenance medium. The results showed that providing CO2 with different duration significantly affected (P <0.01) among treatments. The highest specific growth rate of C. racemosa var.uvifera was in the B (5.270 +0.022)% per day and the lowest in E (1.908 +0.069)% per day. The CO2 contents in treatment B ranged from 95.88 to 108.11 with a pH ranging from 7.0 to 8.4 and CO2 contents in treatment E was 382.87-412.08 with a pH ranging from 6.0 to 8.0.Keywods: Growth, CO2, pH, Caulerpa racemosa AbstrakRumput laut jenis Caulerpa racemosa var. uvifera walaupun sudah musimnya tumbuh kadang tidak ditemukan di perairan, karena kondisi lingkungan sangat mempengaruhi. Hal ini mengakibatkan produksi jenis tanaman tersebut langka, sehingga perlu dilakukan budidaya. Penelitian ini bertujuan untuk mengkaji pemberian CO2 yang berbeda terhadap pH media air pemeliharaan pada pertumbuhan C. racemosa var. uvifera. Penelitian ini menggunakan 5 perlakuan dengan 3 kali pengulangan, yaitu : A (tanpa CO2 sebagai kontrol), B (pemberian CO2 selama 6 menit per hari), C (pemberian CO2 selama 12 menit per hari), D (pemberian CO2,18 menit per hari) dan E (pemberian CO2 selama 24 menit per hari). Data yang diamati berupa berat basah dan kualitas air yang digunakan sebagai media pemeliharaan.  Hasil penelitian menunjukkan bahwa pemberian CO2 dengan lama waktu yang berbeda memberikan pengaruh yang sangat nyata (p<0,01) antar perlakuan. laju pertumbuhan spesifik C. racemosa var.uvifera tertinggi pada perlakuan B (5,270+0,022) % per hari dan terendah pada perlakuan E (1,908+0,069) % per hari. CO2 yang terkandung pada perlakuan B berkisar 95,88-103,11 dengan pH berkisar 7,0-8,4 dan CO2 pada perlakuan E sebesar 382,87-412,08 dengan pH berkisar 6,0-8,0. Kata kunci : Pertumbuhan, CO2, pH, Caulerpa racemosa

scholarly journals The source material in the creation of late-maturing variety of fiber-flax Fenix

2019 ◽  
pp. 36-39
Author(s):  
Elena Alexandrovna Trabyrova ◽  
Svetlana Mikhailovna Зуева ◽  
Sergey Mikhailovich Chekhalkov ◽  
Aminat Msostovna Konova ◽  
Anna Yurievna Gavrilova
Keyword(s):  
Environmental Factors ◽  
Linum Usitatissimum ◽  
Growing Season ◽  
Source Material ◽  
Standard Variety ◽  
Fiber Flax ◽  
Linum Usitatissimum L ◽  
Flax Seeds ◽  
Variety Testing ◽  
Flax Straw

In the comparative variety testing it was evaluated promising material of fiber-flax (Linum usitatissimum L.). The aim of the work was to identify the most valuable cultivar fiber-flax according to their  economic and biological characteristics, and adaptability to adverse environmental factors.  Valuable forms of fiber-flax on the main economically significant features were identified in the Smolensk region. The total length of the stem of A-11 and L-198 exceeded the standard S-108 by 8 - 10%. The duaration of the growing season in all studied varieties was 5 days longer than that of the standard variety.   L-198 exceeded the standard S-108, both in yield of flax straw and fiber content in the stem, the excess was 9 and 3%, respectively. The highest yield of flax seeds (0,58 t/ha) was also in L-198 (21% higher than in the standard). The yield of long fiber in the stem of this sample was 20,1%, which is 0,8% higher compared to the standard. The calculation of the economic efficiency of cultivation of the L-198 variety for fiber-flax seeds also showed its advantage over the S-108 standard.

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