# Review of Land Surface Albedo: Variance Characteristics, Climate Effect and Management Strategy
## 4 Climate Feedback and Management Strategy for Surface Albedo
### Monitoring Short-to-Long-Term Albedo Change and Climate Effects  
#### 4.1.1 Relationships between Surface Albedo Variance and Climate Feedback  
Soil and vegetation are always studied together due to their closely dependent relationship. Although higher surface albedo was observed for desertification soil after removing vegetation due to overgrazing [160], denuded surfaces show positive climate feedback at higher temperatures than vegetated surfaces due to the thermal effect of soil [161]. Surface albedo shows the potential to identify arid ecosystems considering its abrupt and discontinuous increase with increased aridity [162; 163]. There remains a close link between forest canopy albedo and environmental conditions (e.g., atmospheric nitrogen deposition, temperature and precipitation); therefore, it is important to elucidate the ecological mechanisms involved [69]. For temperate and boreal forests, both CO\({}_{2}\) uptake capacity and canopy nitrogen concentration are strongly and positively correlated with shortwave surface albedo [94]. A reduction in surface albedo was observed due to burn scars, and biomass burning aerosols showed positive direct radiative forcing close to 0.1 W/m\({}^{2}\)[164]. Liana-specific optical traits from thinner leaves with lower pigment concentrations show high efficiency in light interception, which can increase tropical forest albedo by 14% in the shortwave and reduce tree (\(-\)19%) and ecosystem (\(-\)7%) gross primary productivity (GPP), despite a significant increase in liana GPP (+27%) [165]. The climate effects of agricultural biofuel albedo with CO\({}_{2}\) and other greenhouse gas emissions have been investigated by life cycle assessment (LCA), which shows a small cooling effect (e.g., corn ethanol, \(-\)1.8 g CO\({}_{2}\) equivalent (CO\({}_{2}\)-eq) for a mega-Joule (MJ) of corn ethanol) and a stronger (e.g., switchgrass ethanol, 12.1 g CO\({}_{2}\)-eq) and less warming effect (e.g., miscanthus ethanol, 2.7 g CO\({}_{2}\)-eq) [106]. Flower albedo can affect soil microclimates, and sunflower plots with abundant flowers were found to lead to warmer (up to 1.2 \({}^{\circ}\)C) and drier soils and increased plant water stress compared to plots with flowers removed [110]. Similarly, snow, ice and water are also strongly associated with each other, which can be interconverted along with changes in temperature and weather [17]. The extent of snow cover and sea ice in the Northern Hemisphere has declined since 1979 with a declined cooling effect of 0.45 W/m\({}^{2}\), coincident with hemispheric warming and indicative of a positive surface albedo feedback effect of surface albedo on climate as well as the total impact of the cryosphere [166]. In particular, the high albedos of snow and ice surfaces show a large effect on radiative forcing. Snowfall-induced high albedo in postfire forest areas during spring forest recovery shows large variations (e.g., \(\sim\)0.6) [167] and presents a predominantly negative radiative forcing [156; 168], and the reduction in snow has led to an increase in Swiss spring temperatures by approximately 3-7% during 1961-2011 [169]. On a global scale, snow albedo shows a small climate feedback value of approximately 7% of that of the water vapour impact, while the peak value of snow albedo greatly affects warming during the spring due to its important driving role in regional climate change [27]. Snow and ice albedos are closely related to the mass change (also called mass balance) of snow and ice over these surfaces (e.g., snow water equivalent), which have been investigated over snowpack [170] and five glaciers in the Canadian Arctic [171] in the melt season. Specifically, the upper site of an Alps glacier has mainly experienced positive mass balances with continuously buried impurity layers over the period 1914-2014, whereas negative mass balances appeared with impurity-induced albedo reduction and increased melt at a lower site [131].