Double Seminar on Forest Ecology

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Seminar
October 13, 2022

Aula Petita del CRM

12h - 14h

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12h-13h | Bifurcated response of a regional forest to draught

Abstract:

Several lines of evidence suggest that forest growth in many regions is declining as a consequence of changing climate. To predict the fate of forests in the future, a quantitative understanding of how the key climate variables (insolation, precipitation and temperature) interact with forests to cause the decline, is a pressing need. My group has tried to use a regionally-averaged tree-ring width index (RWIr) to quantify forest growth in the Southwest United States (SWUS). We show that over a period of 90 years, SWUS RWIr bifurcated into forest stands with enhanced (healthy) and reduced (declining) branches when regressed on shortwave-radiation and temperature, respectively. The reduced branch was controlled overwhelmingly by drought as measured with a regionally-averaged precipitation–evapotranspiration index (SPEIr). Our results provide insights into how to differentiate functions of climate impacts on forest growth and how to identify tipping-point control parameters for forest regime transitions.

SPEAKER
Chuixiang Yi

Chuixiang Yi

School of Earth and Environmental Sciences, Queens College of the City University of New York

Chuixiang Yi received a Bachelor of Science in Physics from Liaoning Normal University (Dalian, China), Master of Science in Theoretical Physics from Northeast Normal University (Changchun, China), and Ph.D. in Atmospheric Sciences from Nanjing University (Nanjing, China). Before he moved to the USA, Dr. Yi served as an Associate Professor at Beijing Normal University (Beijing, China). He has accumulated ten years of post-doc research experience in the USA across many campuses, including University of California, Berkeley, University of Minnesota, Pennsylvania State University, and the University of Colorado. He is now a Professor at Queens College, City University of New York. Dr. Yi is a micrometeorologist and theoretical modeler studying how climate change affects the carbon cycle, and ultimately how these changes to the carbon cycle may alter our environment and further alter our climate in the future. Dr. Yi, along with 150 coauthors, won the World Meteorological Organization’s Norbert-Gerbier-MUMM International Award 2012 for best publication for the paper titled Climate control of terrestrial carbon exchange across biomes and continents (Yi et al., 2010, ERL).

13h-14h | International development for forest and climate action: a call to embrace theory

Abstract:

Climate action is largely driven by societal needs, including grassroots movements. However, decision-making and implementation are in the end only scallable at national levels. Thus, effective planetary climate action is currently only achievable through forums where nations are the agents behind international agreements, such as the United Nations. FAO, as a technical agency of the UN, has a mandate (by consensus among countries) to provide technical support towards mitigating climate change while ensuring the delivery of increasing societal needs, particularly in developing, largely agricultural nations. Here I aim to highlight some of the current efforts by FAO within the forest sector, including embracing open science and new technologies. However a main caveat is necessary: while new statistical procedures are being used to provide more accurate accounting of mitigation actions, technical support is still lacking embracing the use of theoretical insights into the dynamics of forests and societies. This is particularly critical given current warnings coming from nonlinear signatures exemplified by the existence of tipping points and planetary boundaries.

SPEAKER
Javier G. P. Gamarra

Javier G. P. Gamarra

Forestry Division, Food and Agriculture Organization of the United Nations

Javier G.P. Gamarra is an International Consultant on Forestry Statistics in the Forestry Division at FAO during the day and independent (non-paid) researcher at night, specializing in forest estimates and particularly uncertainty measures. He got his PhD with the Complex Systems Research Group under Ricard V. Solé and has postdoc and lecturer experience working on Theoretical Ecology, Hydrobiology and Mathematical Epidemiology at Cornell Univ., Univ. of Alberta and Aberystwyth Univ. He is in the scientific and steering committees of science-i and the Global Forest Biodiversity Initiative and is in the editorial board of Scientific Data.

         Hosted by Josep Sardanyés (CRM)