## 1 Introduction  
Pasture ecosystems transverse more than 40% of earth land surfaces [1], supporting a broad range of biodiversity, conservation, and environmental sustainability [2, 3] while making substantial contributions to global carbon removal [4, 5]. Globally, the livestock industry directly supports the livelihoods of over 1 billion households, particularly in developing countries, where the pastoral system underpins food security [6; 7], often because grasslands are the least expensive form of feed and one of the few ways that extensive land areas can be used for agri-food production [5]. Herein, we define \"pastures\" as uncultivated grasslands or rangelands (shrublands, prazities, woodlands, meadows, steppe, and savannas (Figure 1)) subjected to seasonal native and domesticated livestock grazing. Rangelands are not subject to intensive management except for seasonal grazing [8; 9], often due to their low productivity as determined by seasonal weather [10]. Other pasture types (e.g., sown or exotic species) may originate through the human cultivation of cleared land or conversion from natural grassland. Natural grassland converted to pasture may exclude farm inputs [9], while intensively managed pastures often are subject to management interventions (moving, synthetic fertiliser, irrigation, pasture species renovation, fencing, etc) to enhance productivity to provide financial income [11; 12; 13]. Grasslands may also serve to produce livestock supplementary feeds, such as hay, silage, and grain [9; 14]. Often, pastures are defined based on their global and regional relevance (Figure 1). Many direct and indirect factors can result in the degradation of pasture ecosystems. These may include overgrazing, the inherent soil structure, adverse climate conditions, competing land-use activities or incursions by noxious weeds and/or feral flora and fauna [16; 17; 18; 19; 20; 21; 22; 23; 24]. Decisions to optimise management practices [25] require the support of the efficient and accurate monitoring of production (i.e., quantity), quality, species composition, and availability [4]. Global climate change, including the elevation of temperature and CO\({}_{2}\), will affect pastures, altering the species competition dynamics due to changes in the optimal growth rate [5; 26]. The mechanism by which plant functional types (e.g., C3, C4) adapt to environmental stresses or ecological disturbances has been classified into two main features they possess, i.e., structural and functional characteristics [9]. Pasture composition, functioning, and structure can be vulnerable to the harmful effects of climate change and anthropogenic activities (i.e., overgrazing), and when a critical threshold [27; 28; 29] is reached, may h  
Figure 1: Global distribution of pastures and assessment using remote sensing tools. “Global assessment of land degradation and improvement 1. Identification by remote sensing” ([PERSON] et al., 2008 [15]). Global grassland classification was embellished to the original map by the authors. Avenues for monitoring pasture sustainability indicators fall into three broad categories: field techniques, laboratory/greenhouse/allometric analyses, and proximal sensors. Field techniques to quantify pasture biomass may include (1) visual methods (i.e., field walking and boot height) to estimate grass height, (2) using scientific equipment such as a Rising Plate Meter (RPM) or C-Dax system (a tow-behind device, see www.c-dax.com, accessed on 6 April 2023) to measure the height and density of pastures [3; 30], and (3) destructive harvests through quadrat sampling [26]. While such methods provide data on the ground, previous studies have suggested that such methods cannot adequately account for intra-paddock or intra-seasonal variation [31; 32; 33]. Laboratory, greenhouse and/or allometric analyses facilitate the direct assessment of morphological parameters such as the leaf area index (LAI) and aboveground biomass (AGB) [34; 35; 36; 37].