Greening of the Earth and its drivers

Zhu, Zaichun; Piao, Shilong; Myneni, Ranga B.; Huang, Mengtian; Zeng, Zhenzhong; Canadell, Josep G.; Ciais, Philippe; Sitch, Stephen; Friedlingstein, Pierre; Arneth, Almut; Cao, Chunxiang; Cheng, Lei; Kato, Etsushi; Koven, C.; Li, Yue; Lian, Xu; Liu, Yongwen; Liu, Ronggao; Mao, Jiafu; Pan, Yaozhong; Peng, Shushi; Peñuelas, Josep; Poulter, Benjamin; Pugh, Thomas A. M.; Stocker, Benjamin D.; Viovy, Nicolas; Wang, Xuhui; Ying-ping, Wang; Xiao, Zhiqiang; Yang, Hui; Zaehle, Sönke; Zeng, Ning

doi:10.1038/nclimate3004

Cited by 2,039 publications

(1,751 citation statements)

References 31 publications

Supporting

138

Mentioning

1,584

Contrasting

Unclassified

Order By: Relevance

“…With increasing climate variability and more frequent occurrences of extreme events expected in the future 7 , research has targeted the sensitivity of ecosystems 8,9 . At the same time, recent studies have shown globally increasing leaf area index (LAI; a proxy for green vegetation cover) 10 , and aboveground biomass carbon (ABC) 11 , also known as the greening Earth 10,12 . Dynamic vegetation models and Earth observation studies reveal climatic and atmospheric changes as the main drivers of large scale increases in LAI 10,13 .…”

mentioning

confidence: 99%

Increased vegetation growth and carbon stock in China karst via ecological engineering

et al. 2018

View full text Add to dashboard Cite

T he impacts of climate change and anthropogenic activities on Earth's vegetation and ecosystems have been in the spotlight of science in the past decades [1][2][3][4][5][6] . With increasing climate variability and more frequent occurrences of extreme events expected in the future 7 , research has targeted the sensitivity of ecosystems 8,9 . At the same time, recent studies have shown globally increasing leaf area index (LAI; a proxy for green vegetation cover) 10 , and aboveground biomass carbon (ABC) 11 , also known as the greening Earth 10,12 . Dynamic vegetation models and Earth observation studies reveal climatic and atmospheric changes as the main drivers of large scale increases in LAI 10,13 . On the contrary, the anthropogenic footprint is usually found to cause land degradation and deforestation 13,14 , and only a few studies find a direct positive effect of management on vegetation cover and biomass trends 2,11,15 . Although ecological conservation projects aim at increasing biodiversity, carbon sequestration and vegetation cover 16,17 , the success of such conservation efforts is not easily quantifiable, and the spatial footprint of projects is not always commensurable with contemporary satellite-and modelling-based monitoring methods. Adaptation and mitigation strategies to climate change should be anchored in knowledge on how ecosystems respond to climatic and anthropogenic disturbances, but at present it is not known whether conservation projects impact on the ability of vegetation to alleviate the effects of climate change at large scales.China's ecological restoration projects (for example, the Natural Forest Protection Project, the Grain to Green Project, and the Karst Rocky Desertification Restoration Project) are considered 'megaengineering' activities and the most ambitious afforestation and conservation projects in human history [16][17][18][19] . The highly sensitive and vulnerable karst ecosystem in southwest China is one of the largest exposed carbonate rock areas (more than 0.54 million km 2 ) in the world. This area hosts 220 million people 20,21 and has been selected as a major target of restoration projects. Descriptions as early as the seventeenth century reported the rocky karst mountains as an area of sparse forest or vegetation cover 22 , and accelerating desertification has been reported during the past half century, caused by the increasing intensity of human exploitation of natural resources [21][22][23][24] . As a result, approximately 0.13 million km 2 of karst areas previously covered by vegetation and soil were turned into a rocky landscape. To combat this severe form of land degradation and to relieve poverty, more than 130 billion yuan (~19 billion USD) have been invested in mitigation initiatives since the end of the 1990s 24 . The largest programme implemented, the Grain to Green Project, offers grain, cash and free seedlings as compensation for rural households to re-establish forests, shrub and/or grassland 24 . The costs of ecological engineering projects as a clima...

show abstract

mentioning

confidence: 99%

Increased vegetation growth and carbon stock in China karst via ecological engineering

et al. 2018

View full text Add to dashboard Cite

show abstract

“…Here, we report relative reductions in G S driven by rising VPD on the order of 10% in most forest ecosystems, which would imply even greater relative reductions in canopy stomatal conductance since G S is influenced by soil conductance, which is not sensitive to VPD. While VPD and CO 2 concentrations are assumed to be independent drivers of stomatal conductance in theoretical formulations 17,19 , the extent to which their effects on stomatal conductance are additive remains an important topic for future work, which must also consider the confounding effects of increasing leaf area index 29 .…”

mentioning

confidence: 99%

The increasing importance of atmospheric demand for ecosystem water and carbon fluxes

et al. 2016

View full text Add to dashboard Cite

Soil moisture supply and atmospheric demand for water independently limit-and profoundly a ect-vegetation productivity and water use during periods of hydrologic stress [1][2][3][4] . Disentangling the impact of these two drivers on ecosystem carbon and water cycling is di cult because they are often correlated, and experimental tools for manipulating atmospheric demand in the field are lacking. Consequently, the role of atmospheric demand is often not adequately factored into experiments or represented in models 5-7 . Here we show that atmospheric demand limits surface conductance and evapotranspiration to a greater extent than soil moisture in many biomes, including mesic forests that are of particular importance to the terrestrial carbon sink 8,9 . Further, using projections from ten general circulation models, we show that climate change will increase the importance of atmospheric constraints to carbon and water fluxes in all ecosystems. Consequently, atmospheric demand will become increasingly important for vegetation function, accounting for >70% of growing season limitation to surface conductance in mesic temperate forests. Our results suggest that failure to consider the limiting role of atmospheric demand in experimental designs, simulation models and land management strategies will lead to incorrect projections of ecosystem responses to future climate conditions. Ecosystem moisture stress is often characterized by changes in soil water availability 10,11 . Declining soil moisture impedes the movement of water to evaporating sites at the soil or leaf surface 12 , reducing the surface conductance to water vapour (G S )-a key determinant of carbon and water cycling-and thereby evapotranspiration (ET). However, atmospheric demand for water, which is directly related to the atmospheric vapour pressure deficit (VPD), also affects G S and ET. Plants close their stomata to prevent excessive water loss when VPD is high [13][14][15][16] and thus, increases in VPD during periods of hydrologic stress represent an independent constraint on plant carbon uptake and water use in ecosystems.While the plant physiological community has long recognized the critical role of VPD in determining plant functioning, VPD is often overlooked in many fields of hydrologic and climate science. For example, precipitation manipulation experiments are frequently used to draw conclusions about ecosystem response to drought stress, even though VPD is unaffected by precipitation manipulation 10 . Some terrestrial ecosystem and ecohydrological models do not permit stomatal conductance to vary with atmospheric demand 5,11 . Many models designed to capture these impacts rely on empirical parameterizations for soil moisture and VPD stress that promote compensating effects and model equifinality 5 , and/or use relative humidity instead of VPD as the primary driver, with significant consequences for projections of

show abstract

“…szén-dioxid trágyázási effektus. Földi léptékben -űrfelvételek és ökoszisztéma modellek segítsé-gével -megállapították, hogy ez a hatás a levélfelület index (LAI) növekedésével mérhető "zöldülés" kiváltásában a múltban 70%-ban volt felelős, míg a N-trágyázási effektus csak 9%-ban (Zhu et al 2016). Ezt látszik igazolni az, hogy a fák a tanulmányban a melegedés és szárazodás hatására kimutatott növekedés-csökkenése ellenére az elmúlt időszakban gyorsabban nőttek, mint korábban (Somogyi 2008).…”

Section: öSszefoglaló éRtékelésunclassified

A klímaváltozás miatti fapusztulás tovább gyorsíthatja a klímaváltozást

Somogyi¹

2018

Erdészettudományi Közlemények

View full text Add to dashboard Cite

KivonatA klímaváltozásnak az erdőkre gyakorolt egyik legjelentősebb potenciális hatása az erdők szénegyenlegének jelentős megváltozása. A lehetséges változásokat a CASMOFOR szénkörforgalmi modellel becsültük három hazai fafajra, 2 regionális klímaváltozási és három fakitermelési forgatókönyv szerint. A modellezéshez becsültük a várható szárazodás miatti mortalitás mértékét, valamint a fanövekedés és a fafajösszetétel várható megváltozását. A mortalitást eddigi hazai aszály-elemzési adatokból, a többi változást az Országos Erdőállomány Adattár termőhelyi adatait felhasználó ceteris paribus elemzéssel határoztuk meg. A modellezés többi paraméterét illetően szükséges feltételezéseknél -ahol csak lehetettkonzervatív megközelítést alkalmaztunk. Az eredmények a klímaváltozás hatására nagyon jelentős mortalitás-növekedést, fafajösszetétel-változást és egyértelmű fanövekedés-csökkenést jósolnak; a fakitermelés mértékének változtatása ehhez képest elhanyagolható jelentőségű. Mindez az ország jelenlegi összes üvegház gáz kibocsátásának nagyságrendjét elérő kibocsátást eredményezhet, ami akár teljesen ellensúlyozhatja a nem erdészeti szektorban kifejtett kibocsátás-csökkentési erőfeszítéseket.Kulcsszavak: aszály, mortalitás, fanövekedés, fafajösszetétel, szénforgalom, üvegház gáz kibocsátás. CLIMATE-CHANGE INDUCED FOREST DECLINE CAN FURTHER ENHANCE CLIMATE CHANGE AbstractChanges in the forest carbon cycle are among the projected risks of climate change. In this study, these changes were estimated for three important Hungarian tree species for two regional climate change scenarios and three wood harvesting scenarios using the carbon accounting model CASMOFOR. The effects of changing local climate type on species composition and tree growth were studied under ceteris paribus conditions using appropriate site-related forest inventory information. The effect of projected droughts on mortality was modelled using empirical results of a previous study, while conservative assumptions were applied for the effect of climate change on several less important model parameters. Results demonstrate dramatically increasing mortality, considerably changing species composition and significant drop of tree growth as the risk of drought increases. As a combined effect of all these processes, country-level emissions from forests are projected to reach the order of magnitude of the current total economy-wide greenhouse gas emissions by the second half of the century. By providing positive feedback, these emissions can considerably offset mitigation efforts in non-forestry sectors.

show abstract

Greening of the Earth and its drivers

Cited by 2,039 publications

References 31 publications

Increased vegetation growth and carbon stock in China karst via ecological engineering

Increased vegetation growth and carbon stock in China karst via ecological engineering

The increasing importance of atmospheric demand for ecosystem water and carbon fluxes

A klímaváltozás miatti fapusztulás tovább gyorsíthatja a klímaváltozást

Contact Info

Product

Resources

About