Carbon sequestration in arid‐land forest

Abstract

Rising atmospheric CO2 concentrations may lead to increased water availability because the water use efficiency of photosynthesis (WUE) increases with CO2 in most plant species. This should allow the extension of afforestation activities into drier regions. Using eddy flux, physiological and inventory measurements we provide the first quantitative information on such potential from a 35‐year old afforestation system of Aleppo pine (Pinus halepensis Mill.) at the edge of the Negev desert. This 2800 ha arid‐land forest contains 6.5 ± 1.2 kg C m−2, and continues to accumulate 0.13–0.24 kg C m−2 yr−1. The CO2 uptake is highest during the winter, out of phase with most northern hemispheric forest activity. This seasonal offset offers low latitude forests ∼10 ppm higher CO2 concentrations than that available to higher latitude forests during the productive season, in addition to the 30% increase in mean atmospheric CO2 concentrations since the 1850s. Expanding afforestation efforts into drier regions may be significant for C sequestration and associated benefits (restoration of degraded land, reducing runoff, erosion and soil compaction, improving wildlife) because of the large spatial scale of the regions potentially involved (ca. 2 × 109 ha of global shrub‐land and C4 grassland). Quantitative information on forest activities under dry conditions may also become relevant to regions predicted to undergo increasing aridity.

Coping with Firewood Scarcity in Soroti District of Eastern Uganda

“…Further, Giannecchini (2007) observed that dependence on subsistence farming is an indication of land based activities being fundamental to household livelihoods. According Grunzweig et al (2003), over reliance on crop cultivation leads to more tracks of land to be cleared causing landcover changes. These changes escalate conflicts in the provision food, fuel and roughage on which the livelihoods of poor people critically depends (Bolwing & Odeke, 2007).…”

How drought severity constrains gross primary production(GPP) and its partitioning among carbon pools in a <i>Quercus ilex</i> coppice?

“…According to global and regional climate models, Mediterraneantype ecosystems (MTEs) will suffer longer and more intense droughts as a result of (1) increasing temperature and decreasing rainfall (Hoerling et al, 2011), (2) a change in largescale circulation conditions (Kjellström et al, 2013), and (3) the persistence of heat wave anomalies (Jaeger and Seneviratne, 2011). In MTEs, drought is already the prevailing constraint on the net ecosystem productivity (NEP) (Allard et al, 2008;Grünzweig et al, 2003). This sink strength is likely modified by the differential sensitivity to water limitation of leaf photosynthesis and whole-tree respiration, and of the C allocation to short-and long-lived pools.…”

Biomass Carbon Sequestration Potential by Riparian Forest in the Tarim River Watershed, Northwest China: Implication for the Mitigation of Climate Change Impact

“…Among the numerous types of ecosystems, forest ecosystems play a crucial role in the global carbon budget [1][2][3][4][5][6]. In Central Asia, desert riparian forest ecosystems along large river systems, such as the Amu Darya, Syr Darya, and Tarim River, store a large amount of carbon in the aboveground (leaves, branches, and stems) and belowground (roots) biomass and provide the main biomass resources for human wellbeing in those continental arid regions [7][8][9][10][11]. Due to the extremely arid climate conditions of these regions, the productivity of riparian forest ecosystems is highly dependent on groundwater and soil moisture availability supplied by inland river water flow [12].…”