Effects of grazing control on ecosystem recovery, biological productivity gains, and soil carbon sequestration in long‐term degraded loess farmlands in the Northern Negev, Israel

Abstract

High rainfall variability in drylands complicates comparison in time of productivity and soil fertility, and their changes due to altered management. In order to determine the extent, kinetics, and mechanisms of soil and ecosystem recovery achievable in degraded loess plots in southern Israel, aboveground net primary production (ANPP) and soil quality in three fenced plots were analyzed between 2011 and 2017 for experimental confirmation of previously formulated hypotheses on the ecosystem recovery potential in this area. A degraded control plot [<20% biological productivity, marginal plant biodiversity, 50% reduced soil organic matter (SOM)] was analyzed in the same way to normalize annual growth rates in the protected plots. An abandoned ruminants' enclosure was chosen as a reference plot for maximum achievable values to estimate the duration to full ecosystem recovery. The protected loess areas displayed rapid full recovery of soil moisture measured at the end of the rainy season after 3 years already. Annual normalized ANPP increased 5-fold within 6 years of protection to 3 Mg dry matter per hectare and year, or 60% of the locally achievable maximum ANPP. Herbaceous species numbers increased about 10-fold in the protected plots as compared to the degraded control plot. Normalized soil carbon sequestration rates of 5 Mg CO 2 eq ha −1 yr −1 were deduced from yearly normalized SOM changes. This methodology can be applied universally to determine the true biological production potentials of areas of unknown land degradation/rehabilitation state, and for assessing gains in ecosystem services achievable by restoration of degraded dry agroecosystems such as biodiversity, fodder production, and carbon sequestration.

Reclamation of ancient agricultural terraces in the Negev Highlands; soil, archeological, hydrological, and topographical perspectives

“…The common theory claimed that shrublands were formed from herb‐land due to desertification (Schlesinger et al, 1990). Together with recently published case studies (e.g., Leu et al, 2021), these plots resemble the rehabilitation ability of the area, which may be upslope widened even, as in the cases of wadis, in the confining cliffs. In addition, these plots are long‐timed and continuously grazed, concluding that arranged grazing regime in the wadis area (Figure 5f) does not harm the rehabilitation and may enhance it (Mor‐Mussery et al, 2020a, 2021).…”

“…The most common shrub species is Hammada scoparia , and the less common ones are Anabasis articulate and Lycium shawii . Visually, in most of the area, the patches' size seems smaller than in other shrublands in the Negev Highlands (Leu et al, 2021; Mor‐Mussery et al, 2015) and the biocrusted layer is less developed, possibly, due to extreme arid terms and intensive uncontrolled offroad traffic (Webb & Wilshire, 2012).…”

“…In order to determine the agricultural potential of land, first and foremost, it is crucial to define the interrelations between its components (Cotter et al, 2014; Leu et al, 2021), which are here the antique remains and vegetation. An additional aim was to define the constructional state of the northern and southern banks' terraced systems, which will be focused on in the current study.…”

Long-term grazing exclusion increases ecosystem carbon stock but decreases nitrogen stock in the karst alpine grassland of China

“…In this study, both aboveground and root biomass were significantly increased after 17 years of GE, which is in agreement with many other studies conducted in alpine meadows (Xiong, Shi, Sun, Wu, & Zhang, 2014) and semiarid grasslands of China Yu, Sun, & Huang, 2021), highland grasslands of Argentina (Vaieretti et al, 2021), semi-arid grasslands of South Africa (Snyman, 2005), degraded loess farmlands of Israel (Leu, Ben-Eli, & Mor-Mussery, 2021), and temperate grasslands of India (Husain, Geelani, & Bhat, 2021). GE can relieve livestock damage to grassland vegetation, increase vegetation height and cover, alter plant functional groups, and improve photosynthetic material partitioning between aboveground and belowground biomass (Lei Deng, Zhang, & Shangguan, 2014;Gao et al, 2008;Xiong et al, 2014), thus promoting increased productivity of grassland vegetation.…”

Sequestering Organic Carbon in Soils Through Land Use Change and Agricultural Practices: A Review

“…It was noted that intensive production practices with high inputs and rates of removal can deplete SOC stocks [154] . [71] Worldwide review Grassland Organic fertilizer − − 0.84 [71] Worldwide review Grassland Introducing legumes − − 0.66 [71] Worldwide review Grassland Improved grass species − − 3.04 [142] Semi-arid tropical savannah Rangeland Managed (grazing in dry season) vs unmanaged − 30 12.1%-22.2% [146] Semi-arid tropical savannah Rangeland Managed (grazing in wet season) vs unmanaged − 30 nc [146] Arid and semiarid Rangeland Grazing exclusion vs grazing 6 20 26.9% [147] Arid and semiarid Rangeland Grazing exclusion vs grazing > 1 30 0.23 [148] Cold desert Rangeland Grazing exclusion vs grazing 4 20 49% [149] Cold steppe Grassland Grazing exclusion vs light grazing 12 30 −15.6% [150] Cold steppe Grassland Grazing exclusion vs heavy grazing 12 30 14.1% [150] Cold semi-arid Grassland Grazing exclusion vs light grazing 55 30 49.4% [150] Cold semi-arid Grassland Grazing exclusion vs heavy grazing 55 30 46.9% [150] Temperate Grassland Fertilized P vs non application > 20 60 25.5% [151] Temperate Grassland Multiple sward (5 species) 9 30 1.6 [152] Temperate Grassland Multiple sward (2 species) 9 30 0.44 [152] Semiarid Rangeland Grazing exclusion > 75 60 0.128 [153] Semiarid Rangeland Light grazing (0.78 sheep Eq ha −1 ) > 75 60 0.097 [153] Semiarid rangeland heavy grazing (1.18 sheep Eq ha −1 ) > 75 60 0.093 [153] Note: nc, no substantive change.…”