Archives par mot-clé : Forests

Historical deforestation locally increased the intensity of hot days in northern mid-latitudes

by Q. Lejeune et al., April 23, 2018 in Nature


The effects of past land-cover changes on climate are disputed. Previous modelling studies have generally concluded that the biogeophysical effects of historical deforestation led to an annual mean cooling in the northern mid-latitudes, in line with the albedo-induced negative radiative forcing from land-cover changes since pre-industrial time reported in the most recent Intergovernmental Panel on Climate Change report. However, further observational and modelling studies have highlighted strong seasonal and diurnal contrasts in the temperature response to deforestation

(…)

Claim: U.N. data reflects greening of the Earth, not carbon dioxide

by A. Watts, May 15, 2018 in WUWT


NASA says the greening of the planet is due to increased CO2, these guys are arguing against that, saying increased forest growth “correlates strongly to the UN Development Programme’s Human Development Index”. Riiiighht. They say that “Europe’s early turnaround and expansion of forest resources obviously can’t be attributed to the rapid rise of atmospheric carbon dioxide that began decades later”. By the same token, the U.N. didn’t exist until decades later, and they sure as hell haven’t had any impact on the greening of the Eastern United States as shown in their map below (…)

Climate value of Earth’s intact forests

by Wildlife Conservation Society, February 26, 2018 in ScienceDaily


With over 80 percent of forests already degraded by human and industrial activities, today’s findings underscore the immediate need for international policies to secure remaining intact forests — including establishing new protected areas, securing the land rights of indigenous peoples, regulating industry and hunting, and targeting restoration efforts and public finance. Absent specific strategies like these, current global targets addressing climate change, poverty, and biodiversity may fall short, including the United Nations’ Sustainable Development Goals to sustainably manage forests, combat desertification, halt and reverse land degradation and halt biodiversity loss.

BOOM: Global land use change responsible for a significant portion of global warming says study

by A. Watts, February 20, 2018 in WUWT


From the EUROPEAN COMMISSION JOINT RESEARCH CENTRE and the “Dr. Roger Pielke Sr. was right” department. I suspect a whole bunch of climate models that don’t take this into consideration, and think CO2 is the dominant climate driver, are going to need to be revised.

Land use change has warmed the Earth’s surface

Natural ecosystems play a crucial role in helping combat climate change, air pollution and soil erosion. A new study by a team of researchers from the Joint Research Centre, the European Commission’s science and knowledge service, sheds light on another, less well-known aspect of how these ecosystems, and forests in particular, can protect our planet against global warming.

Climate change versus deforestation: Implications for tree species distribution in the dry forests of southern Ecuador

by C.E. Manchego et al.,  December 21, 2017 in PLOS_One


Using presence-only modeling and native forest masks from the Ecuadorian Ministry of Environment, we obtained approximations of characteristic tree species distributions in the dry deciduous forest of southwestern Ecuador, which are threatened by deforestation and climate change. Our estimates indicate that deforestation affects more spatial range than climate change, even under an extreme climate change scenario. Despite this result, climate change may cause additional stress at the species and community levels

Study: climate change accelerates growth in trees, especially urban ones

by  TECHNICAL UNIVERSITY OF MUNICH, November 14, 2017 in WUWT


While the effects of climate change on tree growth in forests have been extensively studied, there is little information available so far for urban trees”, said Professor Hans Pretzsch from the Chair for Forest Growth and Yield Science at TUM. The study supported by the Bavarian State Ministry for Environment and Consumer Protection as well as by the Audi Foundation for the Environment, which was published in the journal Scientific Reports, for the first time systematically examined the growth of urban trees worldwide for trends resulting from changing environmental conditions.

The Impact of Elevated CO2 on a Widespread Ectomycorrhizal Fungi

by McCormack et al., 2017, September 18, 2017 in FungalEcology


In light of the above findings, it would appear that, given the near-global distribution of this EM fungi and its importance in stimulating ecosystem productivity, the positive impact of elevated CO2 on C. geophilumproduction (~50% increase for a 200 ppm rise) represents a welcomed benefit for the future of Earth’s forests.

Soil carbon debt of 12,000 years of human land use

by J. Sanderman et al., July 2017 in PNAS


Human appropriation of land for agriculture has greatly altered the terrestrial carbon balance, creating a large but uncertain car- bon debt in soils. Estimating the size and spatial distribution of soil organic carbon (SOC) loss due to land use and land cover change has been difficult but is a critical step in understand- ing whether SOC sequestration can be an effective climate mitigation strategy.

See also here

Why there are so many species of tropical trees and other organisms

by Washington University in St-Louis, June 29, 2017 in ScienceDaily


If aliens sent an exploratory mission to Earth, one of the first things they’d notice — after the fluffy white clouds and blue oceans of our water world — would be the way vegetation grades from exuberance at the equator through moderation at mid-latitudes toward monotony at higher ones. We all learn about this biodiversity gradient in school, but why does it exist?

La crédibilité climat de l’UE menacée par les règles concernant la forêt

by  Dr. Joanna House, 16 juin 2017, in Euractiv


L’atténuation du changement climatique grâce au secteur forestier doit être mesurée par une approche scientifique objective. Elle ne doit pas permettre aux États de masquer les impacts des politiques responsables de l’augmentation nette de leurs émissions.

Dr Joanna House est maitre de conférence en sciences et politique environnementales à l’Institut Cabot, à l’Université de Bristol. Elle co-signe cette tribune avec d’autres spécialistes de l’environnement. 

Earth’s forests just grew 9% in a new satellite survey

by J.F. Bastin et al., May 11, 2017 in ScienceDaily

in Science May 11, 2017

The Age of Exploration may be long past, but even in the 21st century, our maps can still get a major update. Using satellite imagery, a new study has found hidden forests all over the world—almost enough for a second Amazon—in areas with little moisture known as drylands.

 


A new estimate of dryland forests suggests that the global forest cover is at least 9 percent higher than previously thought. The finding will help reduce uncertainties surrounding terrestrial carbon sink estimates.

See also L‘équipe d’un chercheur belge découvre 467 millions d’hectares de forêt passés sous les radars

Methane emissions from trees

Tree trunks act as methane source in upland forests

by University of Delaware, March 30, 2017


Methane is about 25 times stronger than carbon dioxide, with some estimates as high as 33 times stronger due to its effects when it is in the atmosphere.

Because of methane’s global warming potential, identifying the sources and “sinks” or storehouses of this greenhouse gas is critical for measuring and understanding its implications across ecosystems.

Daniel L. Warner, Samuel Villarreal, Kelsey McWilliams, Shreeram Inamdar, Rodrigo Vargas. Carbon Dioxide and Methane Fluxes From Tree Stems, Coarse Woody Debris, and Soils in an Upland Temperate ForestEcosystems, 2017; DOI: 10.1007/s10021-016-0106-8