Inter-annual variation in growing season length of a tropical seasonal forest in northern Thailand

Yoshifuji, Natsuko; Kumagai, Tomo’omi; Tanaka, Katsunori; Tanaka, Nobuaki; Komatsu, Hirokazu; Suzuki, Masatoshi; Tantasirin, Chatchai

doi:10.1016/j.foreco.2006.04.013

Cited by 71 publications

(69 citation statements)

References 29 publications

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“…Dry season leaf senescence can cause confusion in forest change analysis which can lead to higher error frequently reported in deciduous classes [57][58][59]. Besides seasonal variation in reflectance increasing with forest deciduousness [60], there can also be considerable natural inter-annual variation linked to changing climate and variable rainfall patterns [61][62][63]. This presents a major challenge for methods that use ridged seasonal models as they often model a constant average seasonality, failing to capture the natural variation.…”

Section: Model Sensitivity To Forest Type and Seasonalitymentioning

confidence: 99%

Mapping Clearances in Tropical Dry Forests Using Breakpoints, Trend, and Seasonal Components from MODIS Time Series: Does Forest Type Matter?

et al. 2016

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Tropical environments present a unique challenge for optical time series analysis, primarily owing to fragmented data availability, persistent cloud cover and atmospheric aerosols. Additionally, little is known of whether the performance of time series change detection is affected by diverse forest types found in tropical dry regions. In this paper, we develop a methodology for mapping forest clearing in Southeast Asia using a study region characterised by heterogeneous forest types. Moderate Resolution Imaging Spectroradiometer (MODIS) time series are decomposed using Breaks For Additive Season and Trend (BFAST) and breakpoints, trend, and seasonal components are combined in a binomial probability model to distinguish between cleared and stable forest. We found that the addition of seasonality and trend information improves the change model performance compared to using breakpoints alone. We also demonstrate the value of considering forest type in disturbance mapping in comparison to the more common approach that combines all forest types into a single generalised forest class. By taking a generalised forest approach, there is less control over the error distribution in each forest type. Dry-deciduous and evergreen forests are especially sensitive to error imbalances using a generalised forest model i.e., clearances were underestimated in evergreen forest, and overestimated in dry-deciduous forest. This suggests that forest type needs to be considered in time series change mapping, especially in heterogeneous forest regions. Our approach builds towards improving large-area monitoring of forest-diverse regions such as Southeast Asia. The findings of this study should also be transferable across optical sensors and are therefore relevant for the future availability of dense time series for the tropics at higher spatial resolutions.

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Section: Model Sensitivity To Forest Type and Seasonalitymentioning

confidence: 99%

Mapping Clearances in Tropical Dry Forests Using Breakpoints, Trend, and Seasonal Components from MODIS Time Series: Does Forest Type Matter?

et al. 2016

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“…The natural distribution of teak is in tropical deciduous forests in India, Myanmar, Thailand, and Laos [1,2]. In natural teak forests, there are obvious rainy and dry seasons, and the leaves of teak fall in the dry season [1,3,4].…”

Section: Introductionmentioning

confidence: 99%

“…The period of the rainy and dry seasons affect the growth of teak, and increasing the length of the dry season shortened the leaf foliation period [4,5]. In terms of its typical morphological traits, teak has large simple leaves (maximum size is over 2,500 cm 2 ) [6].…”

Section: Introductionmentioning

confidence: 99%

Effects of Bentonite, Charcoal and Corncob for Soil Improvement and Growth Characteristics of Teak Seedling Planted on Acrisols in Northeast Thailand

Kayama

Nimpila

Hongthong

et al. 2016

Forests

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Abstract:When teak (Tectona grandis L. f.) is planted on acrisols in Northeast Thailand, its growth is suppressed by low pH, infertility, and low water holding capacity. To examine materials capable of increasing water holding capacity in soil and improving teak growth, we conducted an experiment with teak seedlings. We selected bentonite, charcoal, and corncob and added these materials at a rate of 4% to sandy soil from northeast Thailand. Teak seedlings were potted on these soils and raised from July 2013 to July 2014. We compared growth, photosynthetic rates, leaf water potential, and concentrations of elements in plant organs among bentonite, charcoal, corncob, and no addition (control) treatments. Water content in the soils was increased for the bentonite and charcoal treatments. Teak seedlings potted in these two conditions did not suffer from drought stress. Comparing the growth traits of the teak seedlings, the charcoal treatment produced larger root growth and promoted the uptake of phosphorus and potassium, whereas the bentonite treatment did not show positive effects on growth or nutrient acquisition. In contrast, the corncob treatment decreased water content in the soil, and teak seedling growth was suppressed. We concluded that charcoal was a useful material to improve teak growth in sandy soils.

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“…Models for estimating rice ET that integrated the plant's physiological characteristics developed over the last few decades Inoue, 1985;Oue, 2004;Yoshimoto et al, 2005;Maruyama and Kuwagata, 2010;Yoshimoto et al, 2011 . Despite the advancement of research on rice ET over the past half century, most of the work relevant to rice ET is limited to a temporal scale up to few years. Although net radiation is considered to be an important driving force for rice ET e.g., Uchijima, 1961 , ET reported in other ecosystems showed that the important controls differ over different temporal scales Yoshifuji et al, 2006;Ryu et al, 2008;Kume et al, 2011;Hirano et al, 2015;Igarashi et al, 2015 . Multi-year measurements of rice ET with a lysimeter were reported in early studies Sato, 1960;Iwakiri, 1965.…”

Section: Introductionmentioning

confidence: 99%

Evapotranspiration in a rice paddy field over 13 crop years

Ikawa

Ono

Mano

et al. 2017

J. Agric. Meteorol.

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Evapotranspiration ET in rice paddy fields has been studied over the past half-century, but despite that long history of rice ET study, not much is known about their inter-annual variation. This study investigates ET in rice paddy fields during the growing season for 13 years 2002 -2014 at one of the longest flux monitoring sites in Japan. The cumulative ET estimated for each growing season 120 days after transplanting was 419 45 SD standard deviation mm/season 3.5 mm d 1 , which increased to 534 64 mm/season 4.4 mm d 1 when energy balance was forced toclose. This study determined that ET was correlated with meteorological conditions defined by potential evaporation E P , and the inter-annual variability of seasonal ET/E P coefficient of variation CV = 4.6 was less than half the variability of ET CV = 10.7 . For most years, the seasonal ET was reasonably estimated as the product of E P and the overall average ET/E P =0.89 , including years that experienced both extremely warm and cold summers. However, the errors in estimation were relatively large for 2008 which experienced high precipitation and 2012 which was characterized by an extremely low leaf area index . Although the seasonal ET/E P was relatively invariable among years, both the seasonal trends of ET and ET/E P greatly differed between years. The inter-annual variability in ET/E P was particularly high at the ripening stage defined as 91 -120 days after transplanting . The ET/E P at this stage was well correlated to precipitation, and the variation was possibly caused by evaporation from intercepted rainfall. The variation in ET/E P associated with precipitation at the ripening stage accounted for 21 of the inter-annual variation of seasonal ET/E P .

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Inter-annual variation in growing season length of a tropical seasonal forest in northern Thailand

Cited by 71 publications

References 29 publications

Mapping Clearances in Tropical Dry Forests Using Breakpoints, Trend, and Seasonal Components from MODIS Time Series: Does Forest Type Matter?

Mapping Clearances in Tropical Dry Forests Using Breakpoints, Trend, and Seasonal Components from MODIS Time Series: Does Forest Type Matter?

Effects of Bentonite, Charcoal and Corncob for Soil Improvement and Growth Characteristics of Teak Seedling Planted on Acrisols in Northeast Thailand

Evapotranspiration in a rice paddy field over 13 crop years

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