scholarly journals Reaching Natural Growth: The Significance of Light and Temperature Fluctuations in Plant Performance in Indoor Growth Facilities

Plants ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1312
Author(s):  
Camilo Chiang ◽  
Daniel Bånkestad ◽  
Günter Hoch

Recommendations for near-natural plant growth under indoor conditions have been described without considering environmental fluctuations, which might have important consequences for researchers and plant producers when comparing results from indoor facilities with natural ecosystems or production. Previous authors proposed that differences in temperature, light quantity, and the lack of their variation are sources of deviations between indoor and outdoor experiments. Here, we investigated the effect of fluctuating light, temperature, and humidity in an indoor environment on plant performance. Seven plant species from different functional plant types were grown outdoors during summer and spring. The same species were then grown in indoor growth chambers under different scenarios of climate complexity in terms of fluctuations of temperature, air humidity, and light: (1) fixed night and day conditions, (2) daily sinusoidal changes, and (3) variable conditions tracking the climate records from the field trials. In each scenario, the average of the environmental variables was the same as in the respective field trial. Productivity-, gas exchange-, and leaf pigment-traits were measured in all plants at the end of the experiments. The plant trait responses were highly dependent on species and treatment, but general trends were observed. The variable condition yielded lower biomass compared to the fixed and sinusoidal conditions, together with a higher specific leaf area and increased chlorophyll concentrations. A principal component analysis (PCA) across all plant traits in response to climatic conditions suggested that at least a sinusoidal fluctuation is recommended for a more natural-like plant performance in indoor growth facilities. However, prevailing significant differences for several traits between field- and indoor-grown plants even under variable climates indicate that additional factors other than those controllable in standard phytotrons (e.g., wind speed and direction, leaf and soil temperature) can still significantly bias plant performance in indoor facilities.

Plants ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1273
Author(s):  
Camilo Chiang ◽  
Daniel Bånkestad ◽  
Günter Hoch

To transfer experimental findings in plant research to natural ecosystems it is imperative to reach near to natural-like plant performance. Previous studies propose differences in temperature and light quantity as main sources of deviations between indoor and outdoor plant growth. With increasing implementation of light emitting diodes (LED) in plant growth facilities, light quality is yet another factor that can be optimised to prevent unnatural plant performance. We investigated the effects of different wavelength combinations in phytotrons (i.e., indoor growth chambers) on plant growth and physiology in seven different plant species from different plant functional types (herbs, grasses and trees). The results from these experiments were compared against a previous field trial with the same set of species. While different proportions of blue (B) and red (R) light were applied in the phytotrons, the mean environmental conditions (photoperiod, total radiation, red to far red ratio and day/night temperature and air humidity) from the field trial were used in the phytotrons in order to assess which wavelength combinations result in the most natural-like plant performance. Different plant traits and physiological parameters, including biomass productivity, specific leaf area (SLA), leaf pigmentation, photosynthesis under a standardised light, and the respective growing light and chlorophyll fluorescence, were measured at the end of each treatment. The exposure to different B percentages induced species-specific dose response reactions for most of the analysed parameters. Compared with intermediate B light treatments (25 and/or 35% B light), extreme R or B light enriched treatments (6% and 62% of B respectively) significantly affected the height, biomass, biomass allocation, chlorophyll content, and photosynthesis parameters, differently among species. Principal component analyses (PCA) confirmed that 6% and 62% B light quality combinations induce more extreme plant performance in most cases, indicating that light quality needs to be adjusted to mitigate unnatural plant responses under indoor conditions.


HortScience ◽  
2015 ◽  
Vol 50 (9) ◽  
pp. 1301-1308 ◽  
Author(s):  
Lori Hoagland ◽  
John Navazio ◽  
Jared Zystro ◽  
Ian Kaplan ◽  
Jose Gomez Vargas ◽  
...  

Local production of organic tomatoes marketed directly to consumers is growing rapidly in the U.S. Midwest. Growers serving this market need cultivars that are well adapted to local climatic conditions, are competitive under organic management, and have end-use quality characteristics desired by their customers. Participatory plant breeding is a powerful, cost-effective approach with potential to engage growers in development of new cultivars optimally adapted to organic farming systems. To initiate a participatory breeding program for organic tomatoes an online grower survey was conducted to identify key plant traits, and a diverse set of tomato germplasm was evaluated under organic management to better understand horticultural constraints and identify adapted germplasm for further development. Tomato growers rated flavor as their top breeding priority, followed by disease resistance with late blight (LB) (Phytophthora infestans), early blight (EB) (Alternaria solani), and septoria leaf spot (SLS) (Septoria lycopersici) identified as the most problematic diseases. In field trials, foliar diseases were problematic in both years, though many entries exhibited partial resistance. Differences among entries in resistance to insect pests such as hornworms (Manduca sexta) were also observed. Yield varied widely among entries with some of the F1 hybrids and heirloom cultivars performing well despite significant disease pressure. Overall, we identified existing cultivars and F1 hybrids with potential to meet the immediate needs of Midwest organic tomato growers, and segregating breeding populations for further selection to be conducted on working organic farms.


Author(s):  
Tayeb Sitayeb ◽  
Ishak Belabbes

Abstract Landscape dynamics is the result of interactions between social systems and the environment, these systems evolving significantly over time. climatic conditions and biophysical phenomena are the main factors of landscape dynamics. Also, currently man is responsible for most changes affecting natural ecosystems. The objective of this work is to study the dynamics of a typical landscape of western Algeria in time and space, and to map the distribution of vegetation groups constitute the vegetation cover of this ecosystem. as well as using a method of monitoring the state of a fragile ecosystem by remote sensing to understand the processes of changes in this area. The steppe constitutes a large arid area, with little relief, covered with low and sparse vegetation. it lies between the annual isohyets of 100 to 400 mm, subjected to a very old human exploitation with an activity of extensive breeding of sheep, goats, and camels. Landsat satellite data were used to mapping vegetation groups in the Mecheria Steppe at a scale of 1: 300,000. Then, a comparison was made between the two maps obtained by a classification of Landsat-8 sensor Operational Land Imager (OLI) acquired on March 18, 2014, and Landsat-5 sensor Thematic Mapper (TM) acquired on April 25, 1987. The results obtained show the main changes affecting the natural distribution of steppe species, a strong change in land occupied by the Stipa tenacissima steppe with 65% of change, this steppe is replaced by Thymelaea microphylla, Salsola vermiculata, lygeum spartum and Peganum harmala steppe. an absence from the steppe Artemisia herba-alba that has also been replaced by the same previous steppes species. The groups with Quercus ilex and Juniperus phoenicea are characterized by a strong regression that was lost 60% of its global surface and transformed by steppe to stipa tenacissima and bare soil.


Forests ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 334
Author(s):  
Norbert Szymański ◽  
Sławomir Wilczyński

The present study identified the similarities and differences in the radial growth responses of 20 provenances of 51-year-old European larch (Larix decidua Mill.) trees from Poland to the climatic conditions at three provenance trials situated in the Polish lowlands (Siemianice), uplands (Bliżyn) and mountains (Krynica). A chronology of radial growth indices was developed for each of 60 European larch populations, which highlighted the interannual variations in the climate-mediated radial growth of their trees. With the aid of principal component, correlation and multiple regression analysis, supra-regional climatic elements were identified to which all the larch provenances reacted similarly at all three provenance trials. They increased the radial growth in years with a short, warm and precipitation-rich winter; a cool and humid summer and when high precipitation in late autumn of the previous year was noted. Moreover, other climatic elements were identified to which two groups of the larch provenances reacted differently at each provenance trial. In the lowland climate, the provenances reacted differently to temperature in November to December of the previous year and July and to precipitation in September. In the upland climate, the provenances differed in growth sensitivity to precipitation in October of the previous year and June–September. In the mountain climate, the provenances responded differently to temperature and precipitation in September of the previous year and to precipitation in February, June and September of the year of tree ring formation. The results imply that both climatic factors and origin (genotype), i.e., the genetic factor, mediate the climate–growth relationships of larch provenances.


2007 ◽  
Vol 37 (3) ◽  
pp. 515-522 ◽  
Author(s):  
Tore Skrøppa ◽  
Ketil Kohmann ◽  
Øystein Johnsen ◽  
Arne Steffenrem ◽  
Øyvind M. Edvardsen

We present results from early tests and field trials of offspring from two Norway spruce ( Picea abies (L.) Karst.) seed orchards containing clones that have been transferred from high altitudes to sea level and from northern to southern latitudes. Seedlings from seeds produced in the low-altitude seed orchard developed frost hardiness later at the end of the growth season, flushed later in field trials, and grew taller than seedlings from seeds produced in natural stands. They had the lowest mortality rate and the lowest frequency of injuries in the field trials. Similar results were observed in seedlings from seeds produced in the southern seed orchard. We found no adverse effects of the changed growth rhythm. Seedlings from two seed crops in the southern orchard, produced in years with a warm and a cold summer, had different annual growth rhythms. The results are explained mainly by the effects of the climatic conditions during the reproductive phase. Seed crops from different years in the same seed orchard may produce seedlings that perform as if they were from different provenances. It is argued that the effects of the climatic conditions during seed production must contribute to the variation among provenances of Norway spruce.


Forests ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 913
Author(s):  
Serajis Salekin ◽  
Cristian Higuera Catalán ◽  
Daniel Boczniewicz ◽  
Darius Phiri ◽  
Justin Morgenroth ◽  
...  

Taper functions are important tools for forest description, modelling, assessment, and management. A large number of studies have been conducted to develop and improve taper functions; however, few review studies have been dedicated to addressing their development and parameters. This review summarises the development of taper functions by considering their parameterisation, geographic and species-specific limitations, and applications. This study showed that there has been an increase in the number of studies of taper function and contemporary methods have been developed for the establishment of these functions. The reviewed studies also show that taper functions have been developed from simple equations in the early 1900s to complex functions in modern times. Early taper functions included polynomial, sigmoid, principal component analysis (PCA), and linear mixed functions, while contemporary machine learning (ML) approaches include artificial neural network (ANN) and random forest (RF). Further analysis of the published literature also shows that most of the studies of taper functions have been carried out in Europe and the Americas, meaning most taper equations are not specifically applicable to tropical tree species. Developing well-conditioned taper functions requires reducing the variation due to species, measurement techniques, and climatic conditions, among other factors. The information presented in this study is important for understanding and developing taper functions. Future studies can focus on developing better taper functions by incorporating emerging remote sensing and geospatial datasets, and using contemporary statistical approaches such as ANN and RF.


Paleobiology ◽  
10.1666/12030 ◽  
2013 ◽  
Vol 39 (2) ◽  
pp. 235-252 ◽  
Author(s):  
Cindy V. Looy

Within conifers, active abscission of complete penultimate branch systems is not common and has been described mainly from juveniles. Here I present evidence for the abscission of penultimate branch systems within early so-called walchian conifers—trees with a plagiotropic branching pattern. The specimens studied originate from a middle Early Permian gymnosperm-dominated flora within the middle Clear Fork Group of north-central Texas. Complete branch systems of three walchian conifer morphotypes are preserved; all have pronounced swellings and smooth separation faces at their bases. The source plants grew in a streamside habitat under seasonally dry climatic conditions. The evolution of active branch abscission appears to correspond to an increase in the size of conifers, and this combination potentially contributed to the restructuring of conifer-rich late Paleozoic landscapes. Moreover, trees shedding branch systems and producing abundant litter have the potential to affect the fire regime, which is a factor of evolutionary importance because wildfires must have been a source of frequent biotic disturbance throughout the hyperoxic Early Permian.


2019 ◽  
Author(s):  
Fons van der Plas ◽  
Thomas Schröder-Georgi ◽  
Alexandra Weigelt ◽  
Kathryn Barry ◽  
Sebastian Meyer ◽  
...  

ABSTRACTEarth is home to over 350,000 vascular plant species1 that differ in their traits in innumerable ways. Yet, a handful of functional traits can help explaining major differences among species in photosynthetic rate, growth rate, reproductive output and other aspects of plant performance2–6. A key challenge, coined “the Holy Grail” in ecology, is to upscale this understanding in order to predict how natural or anthropogenically driven changes in the identity and diversity of co-occurring plant species drive the functioning of ecosystems7, 8. Here, we analyze the extent to which 42 different ecosystem functions can be predicted by 41 plant traits in 78 experimentally manipulated grassland plots over 10 years. Despite the unprecedented number of traits analyzed, the average percentage of variation in ecosystem functioning that they jointly explained was only moderate (32.6%) within individual years, and even much lower (12.7%) across years. Most other studies linking ecosystem functioning to plant traits analyzed no more than six traits, and when including either only six random or the six most frequently studied traits in our analysis, the average percentage of explained variation in across-year ecosystem functioning dropped to 4.8%. Furthermore, different ecosystem functions were driven by different traits, with on average only 12.2% overlap in significant predictors. Thus, we did not find evidence for the existence of a small set of key traits able to explain variation in multiple ecosystem functions across years. Our results therefore suggest that there are strong limits in the extent to which we can predict the long-term functional consequences of the ongoing, rapid changes in the composition and diversity of plant communities that humanity is currently facing.


Helia ◽  
2004 ◽  
Vol 27 (41) ◽  
pp. 113-122 ◽  
Author(s):  
Sankar Maruthi ◽  
M. Vanaja ◽  
V. Maruthi ◽  
Raghuram Reddy ◽  
Murthy Narasimha

2004 ◽  
Vol 78 (1) ◽  
pp. 139-147 ◽  
Author(s):  
M. Zähner ◽  
L. Schrader ◽  
R. Hauser ◽  
M. Keck ◽  
W. Langhans ◽  
...  

AbstractThis study aimed to assess whether cows are able to cope with the range of climatic conditions they are exposed to in open stables on commercial farms in central Europe. On each of four farms, ten lactating cows were observed over a total of five weeks in winter, spring and summer. Based on continuous measurements of air temperature (–13·8 to 28·7ºC) and relative air humidity (0·26 to 0·99), a mean value of a temperature humidity index (THI) was calculated for each farm and each observation day for night and day.THI had significant effects on skin temperature and body surface temperature (infra-red thermography) both during night and day. Rectal temperature, duration of lying and cortisol concentration in the milk was significantly affected by THI during the day but not during the night. Heart rate and frequency of lying did not significantly covary with THI. Differences between farms and interactions between THI and farm were significant for most parameters. These results suggest that the climatic conditions during the day induced stronger thermoregulatory responses than the conditions during the night. Within the measured range of climatic conditions the cows were hardly exposed to severe cold or heat stress.


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