TY - JOUR

T1 - Grazing intensity alters the plant diversity‐ecosystem carbon storage relationship in rangelands across topographic and climatic gradients

AU - Sanaei, Anvar

AU - Sayer, Emma J.

AU - Yuan, Zuoqiang

AU - Saiz, Hugo

AU - Delgado‐Baquerizo, Manuel

AU - Sadeghinia, Majid

AU - Ashouri, Parvaneh

AU - Ghafari, Sahar

AU - Kaboli, Hasan

AU - Kargar, Mansoureh

AU - Seabloom, Eric W.

AU - Ali, Arshad

N1 - This is the peer reviewed version of the following article: Sanaei, A., Sayer, E. J., Yuan, Z., Saiz, H., Delgado-Baquerizo, M., Sadeghinia, M., Ashouri, P., Ghafari, S., Kaboli, H., Kargar, M., Seabloom, E. W., & Ali, A. (2023). Grazing intensity alters the plant diversity–ecosystem carbon storage relationship in rangelands across topographic and climatic gradients. Functional Ecology, 37, 703– 718. https://doi.org/10.1111/1365-2435.14270 which has been published in final form at https://besjournals.onlinelibrary.wiley.com/doi/10.1111/1365-2435.14270 This article may be used for non-commercial purposes in accordance With Wiley Terms and Conditions for self-archiving.

PY - 2023/3/31

Y1 - 2023/3/31

N2 - Plant diversity supports multiple ecosystem functions, including carbon sequestration. Recent shifts in plant diversity in rangelands due to increased grazing pressure and climate changes have the potential to impact the sequestration of carbon in arid to semi-humid regions worldwide. However, plant diversity, grazing intensity and carbon storage are also influenced by environmental factors such as nutrient availability, climate and topography. The complexity of these interactions limits our ability to fully assess the impacts of grazing on biodiversity–ecosystem function (BEF) relationships. We assessed how grazing intensity modifies BEF relationships by determining the links between plant diversity and ecosystem carbon stocks (plant and soil carbon) across broad environmental gradients and different plant growth forms. To achieve this, we surveyed 1493 quadrats across 10 rangelands, covering an area of 23,756 ha in northern Iran. We show that above-ground carbon stocks increased with plant diversity across topographic, climatic and soil fertility gradients. The relationship between above-ground carbon stocks and plant diversity was strongest for forbs, followed by shrubs and grasses. Soil carbon stocks increased strongly with soil fertility across sites, but aridity, grazing, plant diversity and topography were also important in explaining variation in soil carbon stocks. Importantly, above-ground and soil carbon stocks declined at high grazing intensity, and grazing modified the relationship between plant diversity and carbon stocks regardless of differences in abiotic conditions across sites. Our study demonstrates that relationships between plant diversity and ecosystem carbon stocks persist across gradients of aridity, topography and soil fertility, but the relationships are modified by grazing intensity. Our findings suggest that potential losses in plant diversity under grazing intensification could reduce ecosystem carbon storage across wide areas of arid to semi-humid rangelands. We discuss the potential mechanisms underpinning rangeland BEF relationships to stimulate future research. Read the free Plain Language Summary for this article on the Journal blog.

AB - Plant diversity supports multiple ecosystem functions, including carbon sequestration. Recent shifts in plant diversity in rangelands due to increased grazing pressure and climate changes have the potential to impact the sequestration of carbon in arid to semi-humid regions worldwide. However, plant diversity, grazing intensity and carbon storage are also influenced by environmental factors such as nutrient availability, climate and topography. The complexity of these interactions limits our ability to fully assess the impacts of grazing on biodiversity–ecosystem function (BEF) relationships. We assessed how grazing intensity modifies BEF relationships by determining the links between plant diversity and ecosystem carbon stocks (plant and soil carbon) across broad environmental gradients and different plant growth forms. To achieve this, we surveyed 1493 quadrats across 10 rangelands, covering an area of 23,756 ha in northern Iran. We show that above-ground carbon stocks increased with plant diversity across topographic, climatic and soil fertility gradients. The relationship between above-ground carbon stocks and plant diversity was strongest for forbs, followed by shrubs and grasses. Soil carbon stocks increased strongly with soil fertility across sites, but aridity, grazing, plant diversity and topography were also important in explaining variation in soil carbon stocks. Importantly, above-ground and soil carbon stocks declined at high grazing intensity, and grazing modified the relationship between plant diversity and carbon stocks regardless of differences in abiotic conditions across sites. Our study demonstrates that relationships between plant diversity and ecosystem carbon stocks persist across gradients of aridity, topography and soil fertility, but the relationships are modified by grazing intensity. Our findings suggest that potential losses in plant diversity under grazing intensification could reduce ecosystem carbon storage across wide areas of arid to semi-humid rangelands. We discuss the potential mechanisms underpinning rangeland BEF relationships to stimulate future research. Read the free Plain Language Summary for this article on the Journal blog.

KW - Ecology

KW - Evolution

KW - Behavior and Systematics

U2 - 10.1111/1365-2435.14270

DO - 10.1111/1365-2435.14270

M3 - Journal article

VL - 37

SP - 703

EP - 718

JO - Functional Ecology

JF - Functional Ecology

SN - 0269-8463

IS - 3

ER -