scholarly journals Characterizing and forecasting the responses of tropical forest leaf phenology to El Nino by machine learning algorithms

PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0255962
Author(s):  
Taninnuch Lamjiak ◽  
Rungnapa Kaewthongrach ◽  
Booncharoen Sirinaovakul ◽  
Phongthep Hanpattanakit ◽  
Amnat Chithaisong ◽  
...  
Keyword(s):  
Climate Change ◽  
Machine Learning ◽  
Climate Variability ◽  
Prediction Model ◽  
Tropical Forests ◽  
El Nino ◽  
Lag Time ◽  
Leaf Phenology ◽  
Dipterocarp Forest ◽  
Dry Dipterocarp Forest

Climate change and global warming have serious adverse impacts on tropical forests. In particular, climate change may induce changes in leaf phenology. However, in tropical dry forests where tree diversity is high, species responses to climate change differ. The objective of this research is to analyze the impact of climate variability on the leaf phenology in Thailand’s tropical forests. Machine learning approaches were applied to model how leaf phenology in dry dipterocarp forest in Thailand responds to climate variability and El Niño. First, we used a Self-Organizing Map (SOM) to cluster mature leaf phenology at the species level. Then, leaf phenology patterns in each group along with litterfall phenology and climate data were analyzed according to their response time. After that, a Long Short-Term Memory neural network (LSTM) was used to create model to predict leaf phenology in dry dipterocarp forest. The SOM-based clustering was able to classify 92.24% of the individual trees. The result of mapping the clustering data with lag time analysis revealed that each cluster has a different lag time depending on the timing and amount of rainfall. Incorporating the time lags improved the performance of the litterfall prediction model, reducing the average root mean square percent error (RMSPE) from 14.35% to 12.06%. This study should help researchers understand how each species responds to climate change. The litterfall prediction model will be useful for managing dry dipterocarp forest especially with regards to forest fires.

Impacts of a strong El Niño event on leaf phenology and carbon dioxide exchange in a secondary dry dipterocarp forest

2020 ◽  
Vol 287 ◽  
pp. 107945
Author(s):  
Rungnapa Kaewthongrach ◽  
Amnat Chidthaisong ◽  
Doojdao Charuchittipan ◽  
Yann Vitasse ◽  
Montri Sanwangsri ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
El Niño ◽  
El Nino ◽  
Leaf Phenology ◽  
Carbon Dioxide Exchange ◽  
Dipterocarp Forest ◽  
El Niño Event ◽  
Dry Dipterocarp Forest

scholarly journals Estimation of biomass for calculating carbon storage and CO2 sequestration using remote sensing technology in Yok Don National Park, Central Highlands of Vietnam

2012 ◽  
Vol 3 (1) ◽  
pp. 14-18 ◽  
Author(s):  
Viet Luong Nguyen
Keyword(s):  
Climate Change ◽  
Remote Sensing ◽  
Tropical Forests ◽  
National Park ◽  
Dry Forest ◽  
Viet Nam ◽  
Dipterocarp Forest ◽  
Ground Biomass ◽  
Central Highlands ◽  
Dry Dipterocarp Forest

Global warming and climate change are closely related to the amount of CO2 in the air. Forest ecosystem plays very important role in the global carbon cycle; CO2 from the atmosphere is taken up by vegetation and stored as plant biomass. Therefore, quantifying biomass and carbon sequestration in tropical forests has a significant concern within the United Nations Framework Convention on Climate Change (UNFCC), Kyoto Protocol and Reducing Emission from Deforestation and Forest Degradation (REDD) program for the purpose of the improvement of national carbon accounting as well as for addressing the potential areas for carbon credits, basis for payment for environmental services. The aim of research is to estimate biomass and carbon stocks in tropical forests using remote sensing data for dry forest of central highlands of Vietnam. This result showed that from satellite images of the SPOT, satellites could build the land cover map, carbon map and biomass map of Yok Don National Park, Central Highlands of Vietnam. Through which also the biomass (above ground biomass and below ground biomass) of each type of forest can be calculated. For instance the biomass of the dry forest (Dry Dipterocarp Forest) is 153.49 tones x ha-1, biomass of rich forest is 343.35 tones x ha-1, biomass of medium forest is 210.34 tones x ha-1 and biomass of poor forest & scrub are 33.56 tones x ha-1. Sự ấm lên toàn cầu và biến đổi khí hậu có liên quan chặt chẽ với tổng lượng CO2 trong không khí. Hệ sinh thái rừng có vai trò rất quan trọng trong chu trình các bon toàn cầu; khí CO2 trong khí quyển được hấp thụ bởi thảm thực vật dưới dạng sinh khối. Vì vậy, việc xác định sinh khối và car-bon tích trữ trong rừng nhiệt đới đã có được sự quan tâm đáng kể trong Công ước của Liên hiệp quốc về biến đổikhí hậu (UNFCC), Nghị định thư Kyoto và Chương trình giảm phát thải từ phá rừng và suy thoái rừng (REDD) gần đây, nhằm cho mục đích cải thiện việc tính toán lượng các bon tích trữ cũng như giải quyết các vấn đề tiềm năng cho tín dụng các bon, làm cơ sở cho việc thanh toán cho các dịch vụ môi trường. Mục đích của nghiên cứu này là ước lượng sinh khối và các bon lưu trữ trong các khu rừng nhiệt đới bằng cách sử dụng dữ liệu viễn thám, mà ở nghiên cứu này là cho rừng khộp Tây Nguyên của Việt Nam. Kết quả cho thấy rằng, từ ảnh vệ tinh SPOT có thể xây dựng bản đồ lớp phủ thực vật, bản đồ các bon và bản độ sinh khối của Vườn quốc gia Yok Đôn, Tây Nguyên Việt Nam. Qua đó đã tính toán được sinh khối (bao gồm cả trên mặt đất và dưới mặt đất) như: đối với sinh khối của rừng khô cây họ dầu (Dry Dipterocarp Forest) là 153,59 tấn/ha, sinh khối rừng giàu là 343,35 tấn/ha, sinh khối rừng trung bình là 210,34 tấn/ha và sinh khối rừng nghèo & cây bụi là 33,56 tấn/ha.

VARIABILIDAD CLIMÁTICA, CAMBIO CLIMÁTICO Y PESQUERÍAS EN EL ECUADOR.

2012 ◽  
Vol 1 (1) ◽  
Author(s):  
Johnny Chavarría Viteri ◽  
Dennis Tomalá Solano
Keyword(s):  
Climate Change ◽  
Climate Variability ◽  
Pacific Decadal Oscillation ◽  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
El Niño Southern Oscillation ◽  
El Nino Southern Oscillation ◽  
Current Action ◽  
Palabras Clave

La variabilidad climática es la norma que ha modulado la vida en el planeta. Este trabajo demuestra que las pesquerías y acuicultura costera ecuatorianas no son la excepción, puesto que tales actividades están fuertemente influenciadas por la variabilidad ENSO (El Niño-Oscilación del Sur) y PDO (Oscilación Decadal del Pacífico), planteándose que la señal del cambio climático debe contribuir a esta influencia. Se destaca también que, en el análisis de los efectos de la variabilidad climática sobre los recursos pesqueros, el esfuerzo extractivo también debe ser considerado. Por su parte, la acción actual de la PDO está afectando la señal del cambio climático, encontrándose actualmente en fases opuestas. Se espera que estas señales entren en fase a finales de esta década, y principalmente durante la década de los 20 y consecuentemente se evidencien con mayor fuerza los efectos del Cambio Climático. Palabras Clave: Variabilidad Climática, Cambio Climático, ENSO, PDO, Pesquerías, Ecuador. ABSTRACT Climate variability is the standard that has modulated life in the planet. This work shows that the Ecuadorian  fisheries and aquaculture are not the exception, since such activities are strongly influenced by ENSO variability (El Niño - Southern Oscillation) and PDO (Pacific Decadal Oscillation), considering that the signal of climate change should contribute to this influence. It also emphasizes that in the analysis of the effects of climate variability on the fishing resources, the extractive effort must also be considered. For its part, the current action of the PDO is affecting the signal of climate change, now found on opposite phases. It is hoped that these signals come into phase at the end of this decade, and especially during the decade of the 20’s and more strongly evidencing the effects of climate change. Keywords: Climate variability, climate change, ENSO (El Niño - Southern Oscillation) and PDO  (Pacific Decadal Oscillation); fisheries, Ecuador. Recibido: mayo, 2012Aprobado: agosto, 2012

Climate Variability in the Context of Climate Change: El Niño and Other Oscillations

2008 ◽  
Author(s):  
Cynthia Rosenzweig ◽  
Daniel Hillel
Keyword(s):  
Climate Change ◽  
Climate Variability ◽  
North Atlantic ◽  
El Niño ◽  
El Nino ◽  
Global Climate ◽  
Climate System ◽  
The Arctic ◽  
The Pacific ◽  
Earth’S Climate

The climate system envelops our planet, with swirling fluxes of mass, momentum, and energy through air, water, and land. Its processes are partly regular and partly chaotic. The regularity of diurnal and seasonal fluctuations in these processes is well understood. Recently, there has been significant progress in understanding some of the mechanisms that induce deviations from that regularity in many parts of the globe. These mechanisms include a set of combined oceanic–atmospheric phenomena with quasi-regular manifestations. The largest of these is centered in the Pacific Ocean and is known as the El Niño–Southern Oscillation. The term “oscillation” refers to a shifting pattern of atmospheric pressure gradients that has distinct manifestations in its alternating phases. In the Arctic and North Atlantic regions, the occurrence of somewhat analogous but less regular interactions known as the Arctic Oscillation and its offshoot, the North Atlantic Oscillation, are also being studied. These and other major oscillations influence climate patterns in many parts of the globe. Examples of other large-scale interactive ocean–atmosphere– land processes are the Pacific Decadal Oscillation, the Madden-Julian Oscillation, the Pacific/North American pattern, the Tropical Atlantic Variability, the West Pacific pattern, the Quasi-Biennial Oscillation, and the Indian Ocean Dipole. In this chapter we review the earth’s climate system in general, define climate variability, and describe the processes related to ENSO and the other major systems and their interactions. We then consider the possible connections of the major climate variability systems to anthropogenic global climate change. The climate system consists of a series of fluxes and transformations of energy (radiation, sensible and latent heat, and momentum), as well as transports and changes in the state of matter (air, water, solid matter, and biota) as conveyed and influenced by the atmosphere, the ocean, and the land masses. Acting like a giant engine, this dynamic system is driven by the infusion, transformation, and redistribution of energy.

scholarly journals Learning from Climate Variability: Adaptive Governance and the Pacific ENSO Applications Center

2010 ◽  
Vol 2 (4) ◽  
pp. 311-319 ◽  
Author(s):  
Amanda H. Lynch ◽  
Ronald D. Brunner
Keyword(s):  
Climate Change ◽  
Climate Variability ◽  
El Niño ◽  
El Nino ◽  
Effective Control ◽  
Scientific Management ◽  
Adaptive Governance ◽  
Policy Problem ◽  
The Pacific ◽  
The Face

Abstract Adaptive governance is a pattern that began to emerge from conflicts over natural resources in the American West a few decades ago. This was a pragmatic response to the emerging evidence that effective control was dispersed among multiple authorities and interest groups, that efficiency was only one of the many goals to be reconciled in policy decision processes, and that science itself was politically contested. Climate change as a policy problem exhibits many of these same features and has similarly led to gridlock in international and national forums. But humankind is not without guidance in securing the protection of life, limb, and livelihood in the face of environmental distress, particularly with regard to the challenge of adaptation. One effective analogy can be drawn to adaptations in the face of large climate variability such as El Niño. This paper compares adaptive governance with the tradition of scientific management in the international climate change regime, and it explores an example of adaptive governance in responding to the effects of a severe El Niño event in the Pacific islands. This event illustrates some of the specific kinds of human choices that will be made by those who are concerned about climate change as a policy problem. The basic choice is not scientific management or adaptive governance but continuing with business as usual or opening the frame to a wider range of possibilities.

scholarly journals South American Climatology and Impacts of El Niño in NCEP’s CFSR Data

2013 ◽  
Vol 2013 ◽  
pp. 1-15 ◽  
Author(s):  
Timothy Paul Eichler ◽  
Ana C. Londoño
Keyword(s):  
Climate Change ◽  
South America ◽  
Climate Variability ◽  
El Niño ◽  
El Nino ◽  
Regional Climate ◽  
Reanalysis Data ◽  
Reanalysis Dataset ◽  
The Andes ◽  
The University

Understanding regional climate variability is necessary in order to assess the impacts of climate change. Until recently, the best methods for evaluating regional climate variability were via observation networks and coarse-gridded reanalysis datasets. However, the recent development of high-resolution reanalysis datasets offers an opportunity to better evaluate the climatologically diverse continent of South America. This study compares NCEP’s CFS reanalysis dataset with NCEP’s coarser-resolution reanalysis II dataset to determine if CFS reanalysis improves our ability to represent the regional climate of South America. Our results show several regional differences between the CFSR and Re2 data, especially in areas of large topographical gradients. A comparison with the University of Delaware and TRMM precipitation datasets lends credence to some of these differences, such as heavier precipitation associated with anomalous 925 hPa westerlies over northwestern Peru and Ecuador during El Niño. However, our results also stress that caution is advised when using reanalysis data to assess regional climate variability, especially in areas of large topographical gradient such as the Andes. Our results establish a baseline to better study climate change, especially given the release of IPCC AR5 model simulations.

Predicting Temperature And Precipitation During The Flood Season Based On Teleconnection

2021 ◽  
Author(s):  
Jaewon Jung ◽  
Hung Soo Kim
Keyword(s):  
Climate Variability ◽  
Prediction Model ◽  
El Niño ◽  
Predictive Power ◽  
El Nino ◽  
Climatic Conditions ◽  
La Niña ◽  
Flood Season ◽  
Temperature And Precipitation ◽  
La Nina

Abstract In recent years, the damages resulting from abnormal hydrometeorological climate have substantially increased over the world due to the climate variability and change. Especially, the flood damage has been severely occurred during the flood season almost every year in Korea. For an example, we had the localized heavy rainfalls for 54 days in flood season of 2020 and had huge property damage and loss of life. Therefore, the study needs to be conducted to improve the predictive power of seasonal time-scale forecasts spanning one to several months for the damage reduction and prevention. In this regard, this study aims to provide a priori predictions (several months ahead) of the climate variable at target sites with a statistical method based on teleconnection with global climatic conditions. Herein, the paradigm of the temperature and precipitation prediction in the Geum river basin in Korea is presented. The purposes of the study are also (1) to analyse the characteristics of summer temperatures and precipitation according to the occurrence of El Niño/La Niña and (2) to suggest a seasonal prediction model that can consider the effects of the occurrence of El Niño and La Niña during the flood season. The model is constructed by classifying the data period into El Niño, La Niña, and neutral status. Then we have shown that the prediction model improves the predictive power for the predictions of climate variables such as temperature and precipitation at midlatitude stations which Korea is located. Therefore, this study demonstrates the possibility of improving the predictive power for forecasting temperature and precipitation by the prediction model considering climate variability.

Resilience to Climate Change in Uganda

2019 ◽  
pp. 149-164
Author(s):  
Shuaib Lwasa ◽  
James D. Ford ◽  
Lea Berrang-Ford ◽  
Didacus B. Namanya ◽  
Ambrose Buyinza ◽  
...  
Keyword(s):  
Climate Change ◽  
Public Policy ◽  
Climate Variability ◽  
Tropical Forests ◽  
Climate Change Impacts ◽  
Policy Implications ◽  
The Other ◽  
Economic Activities ◽  
Livestock Systems ◽  
Karamoja Region

In Uganda, the Karamojong Pastoralist and Batwa forest pygmy communities are disproportionately affected by the increasing frequency and magnitude of climate change impacts. Though these communities have long-standing traditional systems to adapt to a changing climate, policymakers and researchers often disregard the adaptations. Programs in the Karamoja region aim to make pastoralism more resilient to climate change, but most ignore pastoralism’s resilience to climate variability and instead focus on changing livestock systems, reducing livestock numbers, adopting crop growing, and diversifying to other economic activities. On the other hand, Batwa forest pygmies have long adapted to climate change in tropical forests by integrating their health systems to the ecosystem. This chapter maps out the policy implications of resilience building in poor communities marginalized by public policy. Gaps, constraints, and opportunities are discussed, in addition to lessons from existing community adaptations that build resilience to climate change.

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