@article {89658, title = {Large frugivores matter more on an island: Insights from island-mainland comparison of plant-frugivore communities.}, journal = {Ecol Evol}, volume = {11}, year = {2021}, month = {2021 Feb}, pages = {1399-1412}, abstract = {

Endozoochory, a mutualistic interaction between plants and frugivores, is one of the key processes responsible for maintenance of tropical biodiversity. Islands, which have a smaller subset of plants and frugivores when compared with mainland communities, offer an interesting setting to understand the organization of plant-frugivore communities vis-a-vis the mainland sites. We examined the relative influence of functional traits and phylogenetic relationships on the plant-seed disperser interactions on an island and a mainland site. The island site allowed us to investigate the organization of the plant-seed disperser community in the natural absence of key frugivore groups (bulbuls and barbets) of Asian tropics. The endemic Narcondam Hornbill was the most abundant frugivore on the island and played a central role in the community. Species strength of frugivores (a measure of relevance of frugivores for plants) was positively associated with their abundance. Among plants, figs had the highest species strength and played a central role in the community. Island-mainland comparison revealed that the island plant-seed disperser community was more asymmetric, connected, and nested as compared to the mainland community. Neither phylogenetic relationships nor functional traits (after controlling for phylogenetic relationships) were able to explain the patterns of interactions between plants and frugivores on the island or the mainland pointing toward the diffused nature of plant-frugivore interactions. The diffused nature is a likely consequence of plasticity in foraging behavior and trait convergence that contribute to governing the interactions between plants and frugivores. This is one of the few studies to compare the plant-seed disperser communities between a tropical island and mainland and demonstrates key role played by a point-endemic frugivore in seed dispersal on island.

}, issn = {2045-7758}, doi = {10.1002/ece3.7151}, author = {Naniwadekar, Rohit and Gopal, Abhishek and Page, Navendu and Ghuman, Sartaj and Ramachandran, Vivek and Joshi, Jahnavi} } @article {93657, title = {Seed fates of four rainforest tree species in the fragmented forests of Anamalais in the southern Western Ghats, India}, journal = {ACTA OECOLOGICA-INTERNATIONAL JOURNAL OF ECOLOGY}, year = {2021}, month = {05/2021}, abstract = {

Seed predation is one of the key ecosystem processes governing the plant population and community structure in forests. Forest fragmentation and habitat loss have been shown to affect seed predation, leading to altered tree recruitment. However, the effects of fragmentation and habitat loss on seed predation are highly variable and context-specific, with limited information from South Asia. For four rainforest tree species in a production landscape of tea and coffee, we examined the influence of forest type (benchmark, N = 3, and fragmented, N = 5, forests) and seed size on the proportion of seeds, 1) predated by vertebrate seed predators, 2) predated by invertebrate seed predators, and 3) removed by vertebrate seed predators. The seed fates were tracked by placing the seeds in four 1 x 1 m plots under the canopy of the tree (N \>= 11 individuals per tree species and 48 trees overall), and camera traps were placed under a subset of trees (N = 29, trap-nights = 712). Overall, we recorded nine species of seed predators, and that the seed predator species composition differed among the four tree species. However, there was no significant difference in either seed predator species composition or their visitations across the forest types. The seeds were more likely to be predated (on average 6\% higher predation) by vertebrate seed predators in the fragments than in the benchmark forests. Medium-seeded species were more likely to be predated by vertebrate seed predators than large-seeded species (on average 41\% higher predation). Invertebrate seed predation and seed removal by vertebrate seed predators had a weak relationship with forest type, with higher invertebrate seed predation in the fragments and higher seed removal in the benchmark forests. With altered seed dispersal patterns resulting from habitat fragmentation and habitat loss, differential seed predation can alter regeneration patterns, thereby influencing adult tree communities in fragmented forests.

}, doi = {10.1016/j.actao.2020.103698}, author = {Gopal, Abhishek and Mudappa, Divya and Raman, TRS and Naniwadekar, Rohit} } @article {79862, title = {Forest cover and fruit crop size differentially influence frugivory of select rainforest tree species in Western Ghats, India}, journal = {BIOTROPICA}, year = {2020}, month = {06/2020}, abstract = {

Forest fragmentation and habitat loss are major disruptors of plant-frugivore interactions, affecting seed dispersal and altering recruitment patterns of the dependent tree species. In a heterogeneous production landscape (primarily tea and coffee plantations) in the southern Western Ghats, India, we examined effects of surrounding forest cover and fruit crop size on frugivory of four rainforest bird-dispersed tree species (N = 131 trees, \>= 30 trees per species, observed for 623 hr). Frugivore composition differed among the four tree species with the large-seededCanarium strictumandMyristica dactyloidesbeing exclusively dependent on large-bodied avian frugivores, whereas medium-seededPersea macranthaandHeynea trijugawere predominantly visited by small-bodied and large-bodied avian frugivores, respectively. Using the seed-dispersal-effectiveness framework, we identified effective frugivores and examined their responses to forest cover and fruit crop size. Results were idiosyncratic and were governed by plant and frugivore traits. Visitations to medium-seededPerseahad a positive relationship with forest cover but the relationship was negative for the large-seededMyristica. In addition, two of the three effective frugivores forPersearesponded to the interactive effect of forest cover and fruit crop size.Frugivore visitations toHeyneawere not related to forest cover or fruit crop, and there were too few visitations toCanariumto discern any trends.These results highlight the context-specific responses of plant-frugivore interactions to forest cover and fruit crop size influenced by plant and frugivore traits.

}, doi = {10.1111/btp.12810}, author = {Gopal, Abhishek and Mudappa, Divya and Raman, TRS and Naniwadekar, Rohit} }