Effects of mast seeding and rodent abundance on seed predation and dispersal of Quercus aliena (Fagaceae) in Qinling Mountains, Central China

Effects of microhabitat on rodent-mediated seed removal of endangered Kmeria septentrionalis in the karst habitat

“…We found that all types of seeds in the four microhabitats had a high removal rate by rodents ( Fig. 3), which is similar to other studies that also reported such high rate of seed removal by rodents (Vander-Wall, 2003;Pan et al, 2016;Li & Zhang, 2007). Only nine rodents were captured, representing a low level of rodent abundance, which may be due to the close proximity of the study area to a village.…”

“…This behavior also increases the chances of seeds reaching a suitable germination habitat and facilitates their distribution (Steele et al, 2015;Wang & Corlett, 2017). The pattern and intensity of seed removal depends on a multitude of biotic and abiotic factors, such as seed traits and availability (Dylewski et al, 2020;Xiao, Zhang & Krebs, 2015), rodent abundance (Li & Zhang, 2007) and habitat characteristics (Wang et al, 2019b;Perea et al, 2012). A seed's microhabitat is one of the most important factors affecting its removal (García-Castaño, Kollmann & Jordano, 2006;Steele et al, 2015).…”

Cascading effects of forested area and isolation on seed dispersal effectiveness of rodents on subtropical islands

“…We found a unimodal relationship between seed dispersal effectiveness and intensity of rodent competition for acorns, as inferred indirectly from acorn crop size and rodent relative abundance. Prior studies have assessed differences in caching probability and seed survival for binary categories such as seed‐rich versus seed‐poor years (Jansen, Bongers, & Hemerik, ; Li & Zhang, ; Wang et al., ) or have assumed a linear effect of per capita seed availability (Xiao et al., ). Our analysis suggests that if seed production or rodent density span a sufficiently large range, trade‐offs between satiation of consumers (at high availability) and competition for limiting resources among dispersal agents (at low availability) can yield intermediate regions of per capita seed availability where seed dispersal effectiveness is greatest.…”

“…In addition, a higher proportion of seeds remain beneath mother trees, where seeds tend to suffer higher mortality because of higher densities of host‐specific seed predators, pathogens and herbivores (Connell, ; Janzen, ; Wright, ). At the other extreme, high competition for acorns or pilferage pressure results in greater seed dispersal (Ouden et al., ; Puerta‐Piñero et al., ), but lower seed survival after scatter‐hoarding (Soné & Kohno, ), because lower seed availability may force rodents to consume cached seeds to satisfy energy needs (Wang et al., ). Our results are consistent with operation of these two mechanisms on seed dispersal effectiveness by rodents in the Thousand Island Lake ecosystem.…”

“…When rodent abundance is very low relative to seed availability, satiation of scatter hoarders leads to a smaller fraction of dispersed seeds (Lichti, Steele, & Swihart, ; Moore, McEuen, Swihart, Contreras, & Steele, ) that tend to be deposited closer to mother trees and with more clumping (Puerta‐Piñero et al., ), all of which are factors that reduce seed dispersal effectiveness. At the other extreme, when rodent abundance is very high relative to seed availability, rodents may disperse more seeds (Ouden, Jansen, & Smit, ), but they ultimately either consume or recover/pilfer most cached seeds to satisfy energy needs, leading to lower post‐dispersal seed survival (Soné & Kohno, ; Wang et al., ) that also negatively affects seed dispersal effectiveness. Thus, the limiting cases of per capita seed availability are predicted to elicit low seed dispersal effectiveness due to lack of dispersal (when availability is high) or lack of survival (when availability is low).…”