@article {121145, title = {Beyond the passive-active dichotomy: aligning research with the intervention continuum framework of ecological restoration}, journal = {RESTORATION ECOLOGY }, year = {2022}, month = {11/2022}, abstract = {

Experts recommend moving beyond the passive-versus-active dichotomy toward an intervention continuum framework of ecological restoration. Restoration science should guide this transition by elucidating the performance of restoration strategies and underlying mechanisms along gradients of intervention intensity, but is constrained by a paucity of relevant comparisons, conflation of restoration goals, and incomplete documentation of interventions in the present literature. Moving beyond the passive-active dichotomy in restoration science requires emphasis on (1) designing studies that compare multiple restoration treatments to identify whether and how benefits accrue with increasing intervention intensity; (2) distinguishing ecological from other ecosystem restoration goals, as goals could modify outcomes at any given intervention intensity level; and (3) documenting restoration goals, methods, and costs consistently and in sufficient detail in publications, for reproducibility in science and practice, and relevance to comparative and synthetic research, in restoration frameworks based on the intervention continuum.

}, doi = {10.1111/rec.13828}, author = {Krishnan, Aparna and Osuri, Anand M} } @article {113529, title = {Small mammals reduce distance dependence and increase seed predation risk in tropical rainforest fragments}, journal = {BIOTROPICA}, year = {2022}, month = {06/2022}, abstract = {

Seed predation and reduced predation risk with distance from conspecific trees are important influences on tree regeneration in tropical forests. Shifts in animal communities, such as an increase in rodents and other small mammals due to forest fragmentation, could alter patterns of seed predation and affect tree regeneration and community dynamics in forest fragments. We performed a field experiment on four native rainforest tree species in the Western Ghats, India, to test whether fragmentation increases seed predation by mammals and alters the distance dependence of seed predation. We monitored seed predation within open and mammal exclosure plots, near and far from the canopies of conspecific trees, in contiguous and fragmented forests. Seed predation of Cullenia exarillata, Ormosia travancorica, and Syzygium rubicundum was markedly higher in forest fragments, and more so within open plots than exclosures, while the predominantly insect-predated Acronychia pedunculata experienced similar predation in contiguous forests and fragments. Seed predation of C. exarillata and S. rubicundum was unrelated to distance from conspecific trees in open plots in both contiguous forests and fragments, in contrast to exclosures that showed marked near versus far differences in seed predation. Our findings suggest that by increasing overall seed predation risk and imposing similar seed predation risk near and far from adults variably across the tree species, small mammals could alter processes that shape tree diversity and species composition in fragmented tropical rainforests.

}, doi = {10.1111/btp.13137}, author = {Krishnan, Aparna and Osuri, Anand M and Krishnadas, Meghna} } @article {53619, title = {Functional Traits of Trees From Dry Deciduous {\textquotedblleft}Forests{\textquotedblright} of Southern India Suggest Seasonal Drought and Fire Are Important Drivers}, journal = {Front. Ecol. Evol.}, year = {2019}, month = {01/2019}, abstract = {

Two dominant biomes that occur across the southern Indian peninsula are dry deciduous {\textquotedblleft}forests{\textquotedblright} and evergreen forests, with the former occurring in drier regions and the latter in wetter regions, sometimes in close proximity to each other. Here we compare stem and leaf traits of trees from multiple sites across these biomes to show that dry deciduous {\textquotedblleft}forest{\textquotedblright} species have, on average, lower height: diameter ratios, lower specific leaf areas, higher wood densities and higher relative bark thickness, than evergreen forest species. These traits are diagnostic of these dry deciduous {\textquotedblleft}forests{\textquotedblright} as open, well-lit, drought-, and fire-prone habitats where trees are conservative in their growth strategies and invest heavily in protective bark tissue. These tree traits together with the occurrence of a C4 grass-dominated understory, diverse mammalian grazers, and frequent fires indicate that large tracts of dry deciduous {\textquotedblleft}forests{\textquotedblright} of southern India are more accurately classified as mesic deciduous {\textquotedblleft}savannas.{\textquotedblright}

}, doi = {10.3389/fevo.2019.00008}, author = {Ratnam, Jayashree and Chengappa, SK and Machado, Siddarth and Nataraj, N and Osuri, Anand M and Sankaran, Mahesh} } @article {26578, title = {Successional status, seed dispersal mode and overstorey species influence tree regeneration in tropical rain-forest fragments in Western Ghats, India}, journal = {Journal of Tropical Ecology}, volume = {33}, year = {2017}, month = {07/2017}, pages = {270-284}, abstract = {

The effects of fragmentation and overstorey tree diversity on tree regeneration were assessed in tropical rain forests of the Western Ghats, India. Ninety plots were sampled for saplings (1{\textendash}5 cm diameter at breast height (dbh); 5{\texttimes}5-m plots) and overstorey trees (\>9.55 cm dbh; 20{\texttimes}20-m plots) within two fragments (32 ha and 18 ha) and two continuous forests. We tested the hypotheses that fragmentation and expected seed-dispersal declines (1) reduce sapling densities and species richness of all species and old-growth species, and increase recruitment of early-successional species, (2) reduce the prevalence of dispersed recruits and (3) increase influence of local overstorey on sapling densities and richness. Continuous forests and fragments had similar sapling densities and species richness overall, but density and richness of old-growth species declined by 62\% and 48\%, respectively, in fragments. Fragments had 39\% lower densities and 24\% lower richness of immigrant saplings (presumed dispersed into sites as conspecific adults were absent nearby), and immigrant densities of old-growth bird-dispersed species declined by 79\%. Sapling species richness (overall and old-growth) increased with overstorey species richness in fragments, but was unrelated to overstorey richness in continuous forests. Our results show that while forest fragments retain significant sapling diversity, losses of immigrant recruits and increased overstorey influence strengthen barriers to natural regeneration of old-growth tropical rain forests.

}, doi = {10.1017/S0266467417000219}, author = {Osuri, Anand M and chakravarthy, Dayani and Divya Mudappa and Raman, Shankar TR and Ayyappan, N and Muthuramkumar, S and Parthasarathy, N} } @article {5216, title = {Contrasting effects of defaunation on aboveground carbon storage across the global tropics.}, journal = {Nat Commun}, volume = {7}, year = {2016}, month = {2016}, pages = {11351}, abstract = {

Defaunation is causing declines of large-seeded animal-dispersed trees in tropical forests worldwide, but whether and how these declines will affect carbon storage across this biome is unclear. Here we show, using a pan-tropical data set, that simulated declines of large-seeded animal-dispersed trees have contrasting effects on aboveground carbon stocks across Earth{\textquoteright}s tropical forests. In our simulations, African, American and South Asian forests, which have high proportions of animal-dispersed species, consistently show carbon losses (2-12\%), but Southeast Asian and Australian forests, where there are more abiotically dispersed species, show little to no carbon losses or marginal gains ({\textpm}1\%). These patterns result primarily from changes in wood volume, and are underlain by consistent relationships in our empirical data (\~{}2,100 species), wherein, large-seeded animal-dispersed species are larger as adults than small-seeded animal-dispersed species, but are smaller than abiotically dispersed species. Thus, floristic differences and distinct dispersal mode-seed size-adult size combinations can drive contrasting regional responses to defaunation.

}, issn = {2041-1723}, doi = {10.1038/ncomms11351}, author = {Osuri, Anand M and Ratnam, Jayashree and Varma, Varun and Alvarez-Loayza, Patricia and Hurtado Astaiza, Johanna and Bradford, Matt and Fletcher, Christine and Ndoundou-Hockemba, Mireille and Jansen, Patrick A and Kenfack, David and Marshall, Andrew R and Ramesh, B R and Rovero, Francesco and Sankaran, Mahesh} }