Responses of forest structure, functions, and biodiversity to livestock disturbances: A global meta‐analysis

Abstract

Habitat degradation and land‐use change driven by the livestock sector are among the major causes of global biodiversity loss. Forests are crucial in maintaining biodiversity and mitigating climate change. Apart from continuing deforestation, forests also face increasing pressure from livestock grazing in the system, which is less understood compared to grasslands. Through a meta‐analysis of 156 articles with 1936 data entries, this study assesses the effect of livestock on forest biodiversity, structure, and functions, varying with livestock types, livestock density, grazing history, and climatic factors. Our results show that livestock overall had a negative impact on the forest structure and functions, reduced species abundance but increased richness. Medium and large mammals, plant communities, and soil were more negatively affected compared to other groups such as birds and invertebrates. Livestock also influenced the role of forests in mitigating climate change. They changed forest carbon stock by reducing plant biomass; however, they did not significantly impact the soil carbon stock or soil greenhouse gas emissions. Ecosystem attributes were more affected in warmer and drier regions and by single species grazing than the mixed grazing. Past livestock grazing history moderates the impacts of livestock, with the strongest negative effect occurred with a history of 1–5 years. Nonetheless, livestock activities also had a positive impact on forest management, such as reducing forest flammability. Our results also indicate the lack of studies on how higher trophic levels respond to livestock disturbances and how grazing intensity moderates the effect, which includes grazing duration and livestock density. The complex responses of forests to livestock in different conditions call for more adaptive management depending on the conservation targets and evolution history.

Cattle Grazing Effects on Vegetation and Wild Ungulates in the Forest Ecosystem of a National Park in Northeastern China

“…That said, a singleyear exclosure experiment in grazed areas in the eastern part of NTLNP in 2016-2017 found higher understory biomass in plots where cattle were excluded (Wang et al, 2019), effectively similar to our results. Moving forward, though exclosure-type experiments may be useful in some contexts (though see Carver and Convery, 2021 regarding fences, and Bernes et al, 2018;Li and Jiang, 2021 for meta-analyses of herbivore impacts), and there is value in determining precise thresholds, we would argue that it is important to recognize that information is always likely to be imperfect, and sometimes it is important to act based on the best available science. Perhaps the key intervention is a long-term adaptive management plan (IUCN, 2020a) that is able to respond to monitoring and emerging best practice.…”

Research needs, environmental concerns, and logistical considerations for incorporating livestock grazing into coastal upland habitat management

“…), Douglas Fir (Pseudotsuga menziesii) and Spruce (Pinaceae) in order of decreasing susceptibility when sufficient woody underbrush is not readily available, but it was not a forage preference (Ellen, 1990). In areas where the primary plant species of concern for conservation benefit could be susceptible to livestock grazing, temporary protective fences or cages have been used until the target vegetation is above reach of livestock grazers (Li and Jiang, 2021;Öllerer et al, 2019).…”

“…Another area of concern and opportunity for grazing identified by survey respondents is its effect on invasive plant species. In other areas of the world, livestock have been successfully used to remove, reduce, or suppress invasive plants (Diamond et al, 2012;Porensky et al, 2018;Rhodes et al, 2021), reduce fire hazards (Davidson, 1996;Manday and West, 1983;Taylor, 2006;Nader et al, 2007), and maintain managed areas (Bates et al, 2009;Li and Jiang, 2021;McEvoy and McAdam, 2008;Öllerer et al, 2019;Porensky et al, 2018;Sharrow et al, 1992;Tasker and Bradstock, 2006), among other benefits. Some concerns expressed by survey respondents were focused on the potential transport and spread of local invasive plant species, such as cogon grass, Chinese tallow, Japanese climbing fern, etc., by livestock through external attachment of seeds (epizoochory) or through the digestive tract (endozoochory).…”

“…In other areas of the world, paired land management techniques (e.g., prescribed burning and grazing) have been used to maintain habitats. For example, cattle, goats, and sheep are actively used in prairies, shrublands, and open forests to reduce fire loads prior to burning, maintain fire breaks, and create or maintain green strips (Bates et al, 2009;Diamond et al, 2012;Li and Jiang, 2021;Tasker and Bradstock, 2006;Taylor, 2006). There are also several potential economic and community benefits of using livestock grazing for natural resource management.…”

Fine-Scale Interactions between Leopard Cats and Their Potential Prey with Contrasting Diel Activities in a Livestock-Dominated Nature Reserve

“…Growing evidence indicates that livestock encroachment can largely modify habitat use and the behaviors of wild animals [ 10 , 11 ]. However, different species may have divergent responses to livestock disturbance [ 12 ], since this disturbance may either strengthen or weaken the interactions between the predators and their prey.…”