Human Disturbance Increases Spatiotemporal Associations Among Mountain Forest Terrestrial Mammal Species

Concepts de base

Human activities can push mammals together into more frequent encounters and associations, which likely influences the coexistence and persistence of wildlife, with potential far-ranging ecological consequences.

Résumé

The study investigated how human disturbances, including habitat modification and direct human presence, influence the spatiotemporal associations among terrestrial mammal species in the Yarlung Zangbo Grand Canyon National Nature Reserve in the eastern Himalayas. The researchers used a systematic camera trapping survey and a context-dependent joint species distribution model to analyze the data.
Key findings:

The incidence of positive spatial associations between species increased from 64% in habitats with lower human modification to 87% in habitats with higher human modification.
Similarly, the incidence of positive spatial associations increased from 65% in habitats with lower human presence to 83% in habitats with higher human presence.
Human presence was associated with increased nocturnality of carnivores, but not ungulates.
Both human modification and human presence were associated with a significant reduction in the time between successive detections of species pairs, indicating more frequent encounters.
The results suggest that human disturbances can compress the spatiotemporal niches of wildlife, leading to increased positive associations between species. This could have far-reaching ecological consequences, such as altering community structure, disease transmission, and local extinctions. The study highlights the importance of understanding how different types of human impacts shape species interactions in order to inform effective conservation strategies.

Stats

"Human activities can push mammals together into more frequent encounters and associations."
"We detected a higher incidence of positive associations in habitats with moderate and higher levels of human modification and human presence compared to those located in habitats with lower disturbance levels."
"We detected a significant reduction of pairwise encounter time at increasing levels of human disturbance, corresponding to more frequent encounters between pairs of species."

Citations

"Our results are therefore demonstrate that human disturbance can upset interspecific associations both on spatial and temporal niche dimensions."
"Ongoing habitat modification, livestock grazing and resource gathering in this region may increase probability of pathogen exchange."
"With increasing human presence and human modification of areas throughout the world, identifying thresholds of anthropogenic activity that shift species relationships, limiting human activity and increasing landscape connectivity across protected areas may be imperative to maintain interspecific spatiotemporal associations that underpin ecosystem resilience."

Idées clés tirées de

Human disturbance increases spatiotemporal associations among mountain forest terrestrial mammal species

by Li,X., Bleis... à www.biorxiv.org 09-29-2023

https://www.biorxiv.org/content/10.1101/2023.09.28.559422v2

Questions plus approfondies

How do the observed changes in spatiotemporal associations between species impact the overall stability and resilience of the ecosystem?

The observed changes in spatiotemporal associations between species can have significant impacts on the overall stability and resilience of the ecosystem. Positive associations among species can influence community dynamics, resource use, and interactions within the ecosystem. When species are pushed together into more frequent encounters and associations due to human disturbance, it can lead to changes in species interactions, competition for resources, and potential shifts in the food web structure. These changes can disrupt the balance of the ecosystem, affecting the distribution of ecological functions that species provide and ultimately influencing ecosystem dynamics. The compression of spatiotemporal niches due to human activities can limit the available habitat and resources for wildlife, potentially leading to increased competition and altered species interactions. This can have cascading effects on the ecosystem's stability and resilience, impacting biodiversity and ecosystem functioning.

What are the potential cascading effects of increased positive associations on community dynamics, such as predator-prey interactions and disease transmission?

Increased positive associations among species can have cascading effects on community dynamics, particularly in terms of predator-prey interactions and disease transmission. In the context of predator-prey interactions, heightened spatiotemporal associations can lead to changes in predator behavior, prey distribution, and predator-prey encounter rates. This can impact predator foraging patterns, prey population dynamics, and overall predator-prey dynamics within the ecosystem. Additionally, increased positive associations can facilitate the transmission of diseases among species. Closer interactions between species due to human disturbance can enhance the spread of pathogens, leading to increased disease transmission rates and potential outbreaks within the wildlife community. These cascading effects can disrupt the balance of the ecosystem, alter species interactions, and impact the overall health and stability of the ecosystem.

Could the compression of spatiotemporal niches due to human disturbance lead to the emergence of novel interactions between species that have not previously co-occurred, and what might be the ecological implications of such novel interactions?

The compression of spatiotemporal niches due to human disturbance can indeed lead to the emergence of novel interactions between species that have not previously co-occurred. As species are forced into closer proximity and more frequent encounters, they may interact in ways that were not common or observed before. These novel interactions can include competition for resources, changes in predator-prey dynamics, and altered species associations. The ecological implications of such novel interactions can be significant. They can disrupt existing ecological relationships, introduce new competitive pressures, and potentially lead to shifts in community structure and composition. Novel interactions may also impact the distribution of species, alter ecosystem functions, and influence the overall resilience of the ecosystem. Understanding and monitoring these emerging interactions is crucial for assessing the long-term implications of human disturbance on biodiversity and ecosystem dynamics.