Precipitation effects on grassland plant performance are lessened by hay harvest

Abstract

Climate and human management, such as hay harvest, shape grasslands. With both disturbances co-occurring, understanding how these ecosystems respond to these combined drivers may aid in projecting future changes in grasslands. We used an experimental precipitation gradient combined with mimicked acute hay harvest (clipping once a year) to examine (1) whether hay harvest influences precipitation effects on plant performance (cover and height) and (2) the role of inter-specific responses in influencing plant performance. We found that hay harvest reduced the strength of precipitation effects on plant performance through changes in bare-ground soil cover. Species performance were mainly influenced by change in abiotic factors, often responding negatively, as hay harvest increased bare-ground amount. Conversely, altered precipitation without hay harvest promoted plant species performance through abiotic factors change first, followed by biotic. Most species, including the dominant grass Schizachyrium scoparium, increased their performance with greater leaf area index (proxy for canopy structure). Our experiment demonstrates that plant performance responds directly to abiotic factors with hay harvest, but indirectly without hay harvest. Positive effects of increasing precipitation were likely due to microhabitat amelioration and resource acquisition, thus inclusion of hay harvest as a disturbance lessens positive impacts of biotic variables on species performance to climate change.

Exploring the Spatiotemporal Dynamics and Driving Factors of Net Ecosystem Productivity in China from 1982 to 2020

“…On the other hand, insufficient or excessive precipitation can adversely affect plants. Drought conditions can limit plant photosynthesis, while excessive precipitation may lead to water stress, affecting the availability of oxygen to the roots [45,46]. This is also consistent with previous research [13,[47][48][49][50].…”

“…On the other hand, drought or excessive rainfall can have a detrimental effect. Limited rainfall can hinder the photosynthesis process due to water scarcity, while too much rainfall can lead to saturation, which can create challenges for oxygen supply to the roots [45,46]. It is noteworthy that the results of the Geodetector method indicate that precipitation is the primary driving factor influencing changes in NEP.…”

Ecology and evolutionary biology beyond the biotic-abiotic distinction

“…A similar variable is leaf area index (LAI), which is the amount of leaf area exposed to light for a given area of ground surface. Because LAI is the sum of areas of leaves, and leaves are, once again, so obviously organismal products, some authors consider LAI biotic (Castillioni et al 2022). Just as often, however, other authors consider it abiotic (Dalrymple et al 2020).…”

“…In terrestrial ecosystems, net primary productivity (NPP) is the amount of carbon captured by photosynthesis minus that consumed by respiration. Because photosynthesis and respiration are, in all their metabolic majesty, so clearly organismal attributes, many authors consider NPP to be a biotic variable (Castillioni et al 2022). Others, however, reasoning that it is a landscape-level attribute and thus part of the large context of a given individual, consider NPP to be abiotic (Dalrymple et al 2020).…”

Modeling the drivers of large herbivore distribution in human‐dominated southern African savannas

“…The vertical cover reduces exposure to adverse climatic conditions (Ager et al, 2003), whereas lateral cover decreases predation risk by reducing prey detectability or makes the predators less visible to prey and hence could mean higher vigilance by prey and thus less foraging (Tufto et al, 1996). Rainfall controls vegetation growth, quantity, and quality (Castillioni et al, 2022) and determines the surface water availability (Redfern et al, 2005). Rainfall received during a wet season affects vegetation growth, the composition of the herbaceous layer, and hence the capacity to produce forage of a suitable quality (Owen‐Smith & Ogutu, 2003), while rainfall during the dry season promotes the retention of green foliage, thereby improving the nutritional quality (Mduma et al, 1999).…”