scholarly journals Maintenance of long-term experiments for unique insights into forest growth dynamics and trends: review and perspectives

2018 ◽  
Vol 138 (1) ◽  
pp. 165-185 ◽  
Author(s):  
Hans Pretzsch ◽  
Miren del Río ◽  
Peter Biber ◽  
Catia Arcangeli ◽  
Kamil Bielak ◽  
...  
Keyword(s):  
Growth Dynamics ◽  
Forest Growth ◽  
Long Term Experiments

Calibration of methods for soil and diagnostic plant analysis in the Hungarian National Fertilization Long-term Trials. I. Comparison of soil P tests for agronomic purposes in the soils of long-term experiments

2011 ◽  
Vol 60 (2) ◽  
pp. 343-358
Author(s):  
Péter Csathó ◽  
Marianna Magyar ◽  
Erzsébet Osztoics ◽  
Katalin Debreczeni ◽  
Katalin Sárdi
Keyword(s):  
Plant Analysis ◽  
Soil P ◽  
Olsen P ◽  
Long Term Experiments ◽  
Soil P Tests

A szabadföldi trágyázási (tartam)kísérletek eredményeit talaj-, illetve diagnosztikai célú növényvizsgálatok segítségével tudjuk kiterjeszteni, általánosítani – figyelembe véve természetesen a kiterjesztés korlátait is. Célszerűnek láttuk ezen túl a talaj könnyen oldható tápelem-, közöttük P-tartalmát is meghatározni a hazánkban hivatalosan elfogadott AL- (ammónium-laktátos) módszer mellett az Európai Unióban és Észak-Amerikában alkalmazott P-tesztekkel is (CaCl2-, H2O-, Olsen-, Bray1-, LE-, Mehlich3- stb.) a hazai OMTK kísérletek talajmintáiban. A kísérleti helyek talajtulajdonságaiban megnyilvánuló jelentős különbségek lehetőséget adnak rá, hogy a talaj P-teszteket – és a növényi P-felvételt – jellegzetes hazai talajokon, sokszor szélsőséges talajparaméterek mellett vizsgáljuk. Az egyes P-szintek között a 28 év átlagában mintegy évi 50 kg P2O5·ha-1volt a különbség. A P0-szinten mért P-tartalmak jól jelezték az egyes kísérleti helyek talajának eltérő P-ellátottságát, illetve, közvetve, fizikai féleségében, pH és mészállapotában meglévő különbségeket. A P2-szinten – a hazai talajokra, P-igényes növényekre a hazai szabadföldi P-trágyázási tartamkísérleti adatbázisban talált összefüggésekre alapozott – új AL-P határértékek szerint csupán a bicsérdi csernozjom barna erdőtalajon nem javult a P-ellátottság legalább a „jó” szintig. Vizsgálataink megerősítették az AL-módszer függőségét a CaCO3-tartalomtól: a Mehlich3 módszerrel való összefüggésben a karbonátmentes és a karbonátos talajok csoportja erőteljesen elkülönült egymástól. Az AL-P korrekció elvégzése, azaz az AL-P értékeknek egy standard talajtulajdonság-sorra való konvertálása (KA: 36; pH(KCl): 6,8; CaCO3: 0,1%) látványosan csökkentette az AL-módszernek a talaj CaCO3-tartalmától való függőségét. Az AL-P és Olsen-P, valamint a korrigált AL-P és Olsen-P tartalmak összehasonlításában ugynakkor ugyanez az összefüggés nem volt állapítható, ami arra utal, hogy az Olsen módszer bizonyos fokig szintén pH- és mészállapot függő. Kísérleti eredményeink megerősítették a Sarkadi-féle AL-P korrekciós modell helytálló voltát. Fenti megállapításunkat ugyanakkor a növényi P-tartalmakkal való összefüggéseknek is igazolniuk kell. Szükséges tehát a talajvizsgálati eredményeknek a diagnosztikai célú növényvizsgálatokkal, valamint a terméseredményekkel való összevetése. A tartamkísérletek talajai lehetőséget nyújtanak a környezetvédelmi célú P-vizsgálatok értékelésére, a talaj P-feltöltöttsége környezeti kockázatának becslésére. Ezekkel a kérdésekkel a cikksorozat további részeiben kívánunk foglalkozni.

scholarly journals Shedding New Light on Mountainous Forest Growth: A Cross-Scale Evaluation of the Effects of Topographic Illumination Correction on 25 Years of Forest Cover Change across Nepal

2021 ◽  
Vol 13 (11) ◽  
pp. 2131
Author(s):  
Jamon Van Den Hoek ◽  
Alexander C. Smith ◽  
Kaspar Hurni ◽  
Sumeet Saksena ◽  
Jefferson Fox
Keyword(s):  
Remote Sensing ◽  
Geographic Distribution ◽  
Classification Accuracy ◽  
Forest Cover ◽  
Forest Growth ◽  
Forest Cover Change ◽  
Scale Evaluation ◽  
Beneficial Effects ◽  
Affect Detection

Accurate remote sensing of mountainous forest cover change is important for myriad social and ecological reasons, but is challenged by topographic and illumination conditions that can affect detection of forests. Several topographic illumination correction (TIC) approaches have been developed to mitigate these effects, but existing research has focused mostly on whether TIC improves forest cover classification accuracy and has usually found only marginal gains. However, the beneficial effects of TIC may go well beyond accuracy since TIC promises to improve detection of low illuminated forest cover and thereby normalize measurements of the amount, geographic distribution, and rate of forest cover change regardless of illumination. To assess the effects of TIC on the extent and geographic distribution of forest cover change, in addition to classification accuracy, we mapped forest cover across mountainous Nepal using a 25-year (1992–2016) gap-filled Landsat time series in two ways—with and without TIC (i.e., nonTIC)—and classified annual forest cover using a Random Forest classifier. We found that TIC modestly increased classifier accuracy and produced more conservative estimates of net forest cover change across Nepal (−5.2% from 1992–2016) TIC. TIC also resulted in a more even distribution of forest cover gain across Nepal with 3–5% more net gain and 4–6% more regenerated forest in the least illuminated regions. These results show that TIC helped to normalize forest cover change across varying illumination conditions with particular benefits for detecting mountainous forest cover gain. We encourage the use of TIC for satellite remote sensing detection of long-term mountainous forest cover change.

scholarly journals Can Long-Term Experiments Predict Real Field N and P Balance and System Sustainability? Results from Maize, Winter Wheat, and Soybean Trials Using Mineral and Organic Fertilisers

Agronomy ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1472
Author(s):  
Ilaria Piccoli ◽  
Felice Sartori ◽  
Riccardo Polese ◽  
Maurizio Borin ◽  
Antonio Berti
Keyword(s):  
Winter Wheat ◽  
Nutrient Balance ◽  
Environmental Indicators ◽  
Nutrient Loss ◽  
Real Field ◽  
Short Term ◽  
Organic Fertiliser ◽  
Long Term Experiments ◽  
P Balance

Agri-environmental indicators such as nutrient balance may play a key role in soil and water quality monitoring, although short-term experiments might be unable to capture the sustainability of cropping systems. Therefore, the objectives of this study are: (i) to evaluate the reliability of long-term experimental N and P balance estimates to predict real field (RF) (i.e., short-term transitory) conditions; and (ii) to compare the sustainability of short- and long-term experiments. The LTE-based predictions showed that crops are generally over-fertilised in RF conditions, particularly maize. Nutrient balance predictions based on the LTE data tended to be more optimistic than those observed under RF conditions, which are often characterised by lower outputs; in particular, 13, 44, and 47% lower yields were observed for winter wheat, maize, and soybean, respectively, under organic management. The graphical evaluation of N and P use efficiency demonstrated the benefit of adopting crop rotation practices and the risk of nutrient loss when liquid organic fertiliser was applied on a long-term basis. In conclusion, LTE predictions may depend upon specific RF conditions, representing potential N and P use efficiencies that, in RF, may be reduced by crop yield-limiting factors and the specific implemented crop sequence.

scholarly journals Development of single-cell-level microfluidic technology for long-term growth visualization of living cultures of Mycobacterium smegmatis

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Han Wang ◽  
Gloria M. Conover ◽  
Song-I Han ◽  
James C. Sacchettini ◽  
Arum Han
Keyword(s):  
Drug Treatment ◽  
Single Cell ◽  
Mycobacterium Smegmatis ◽  
Culture Media ◽  
Low Cost ◽  
Bacterial Pathogen ◽  
Growth Dynamics ◽  
Time Lapse ◽  
Cell Phenotype

AbstractAnalysis of growth and death kinetics at single-cell resolution is a key step in understanding the complexity of the nonreplicating growth phenotype of the bacterial pathogen Mycobacterium tuberculosis. Here, we developed a single-cell-resolution microfluidic mycobacterial culture device that allows time-lapse microscopy-based long-term phenotypic visualization of the live replication dynamics of mycobacteria. This technology was successfully applied to monitor the real-time growth dynamics of the fast-growing model strain Mycobacterium smegmatis (M. smegmatis) while subjected to drug treatment regimens during continuous culture for 48 h inside the microfluidic device. A clear morphological change leading to significant swelling at the poles of the bacterial membrane was observed during drug treatment. In addition, a small subpopulation of cells surviving treatment by frontline antibiotics was observed to recover and achieve robust replicative growth once regular culture media was provided, suggesting the possibility of identifying and isolating nonreplicative mycobacteria. This device is a simple, easy-to-use, and low-cost solution for studying the single-cell phenotype and growth dynamics of mycobacteria, especially during drug treatment.

The analysis of the results of a rotation experiment on the use of straw and fertilizers

1953 ◽  
Vol 43 (1) ◽  
pp. 77-88 ◽  
Author(s):  
H. D. Patterson
Keyword(s):  
Present Experiment ◽  
Treatment Effects ◽  
Standard Errors ◽  
Methods Of Analysis ◽  
Seasonal Factors ◽  
Long Term Experiments ◽  
The Mean ◽  
Linear Regressions

An experiment, designed to test different ways of using straw with fertilizers, and involving a three course rotation of crops, was carried out at Rothamsted between 1933 and 1951. The methods of analysis developed for this experiment are described in the present paper and demonstrated using yields of potatoes.Treatment effects of interest are given by the mean yields over all years and the linear regressions of yield on time. These estimates are straightforward but the evaluation of their errors is complicated by the existence of correlations due to the recurrence of treatments on the same plots. Further complications are introduced when, as frequently happens in long-term experiments, treatment effects show real variation from year to year. A method is given for estimating standard errors which include a contribution from this variation.The various relationships between yields and the uncontrolled seasonal factors can also be examined; in the present experiment there is some indication that the effects of treatments on yields of potatoes are influenced by the dates of planting.In other circumstances the analysis requires modifications, some of which are briefly considered.

Long-Term Experiments in Agricultural and Ecological Sciences.

1995 ◽  
Vol 32 (4) ◽  
pp. 888 ◽  
Author(s):  
A. D. Bradshaw ◽  
R. A. Leigh ◽  
A. E. Johnston
Keyword(s):  
Long Term Experiments

Long‐term growth dynamics of natural forests in Hokkaido, northern Japan

1999 ◽  
Vol 10 (6) ◽  
pp. 815-824 ◽  
Author(s):  
Kiyoshi Umeki ◽  
Kihachiro Kikuzawa
Keyword(s):  
Growth Dynamics ◽  
Natural Forests ◽  
Northern Japan

A Hybrid Broad-Band EEG Frequency Analyzer for Use in Long-Term Experiments

1973 ◽  
Vol BME-20 (1) ◽  
pp. 60-62 ◽  
Author(s):  
Robert W. Silverman ◽  
Donald J. Jenden ◽  
M. David Fairchild
Keyword(s):  
Broad Band ◽  
Long Term Experiments
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