Browsing by Subject "ECOLOGICAL RESPONSES"

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  • Delgado, Maria del Mar; Roslin, Tomas; Tikhonov, Gleb; Meyke, Evgeniy; Lo, Coong; Gurarie, Eliezer; Abadonova, Marina; Abduraimov, Ozodbek; Adrianova, Olga; Akimova, Tatiana; Akkiev, Muzhigit; Ananin, Aleksandr; Andreeva, Elena; Andriychuk, Natalia; Antipin, Maxim; Arzamascev, Konstantin; Babina, Svetlana; Babushkin, Miroslav; Bakin, Oleg; Barabancova, Anna; Basilskaja, Inna; Belova, Nina; Belyaeva, Natalia; Bespalova, Tatjana; Bisikalova, Evgeniya; Bobretsov, Anatoly; Bobrov, Vladimir; Bobrovskyi, Vadim; Bochkareva, Elena; Bogdanov, Gennady; Bolshakov, Vladimir; Bondarchuk, Svetlana; Bukharova, Evgeniya; Butunina, Alena; Buyvolov, Yuri; Buyvolova, Anna; Bykov, Yuri; Chakhireva, Elena; Chashchina, Olga; Cherenkova, Nadezhda; Chistjakov, Sergej; Chuhontseva, Svetlana; Davydov, Evgeniy A.; Demchenko, Viktor; Diadicheva, Elena; Dobrolyubov, Aleksandr; Dostoyevskaya, Ludmila; Drovnina, Svetlana; Drozdova, Zoya; Dubanaev, Akynaly; Kurhinen, Juri (2020)
    For species to stay temporally tuned to their environment, they use cues such as the accumulation of degree-days. The relationships between the timing of a phenological event in a population and its environmental cue can be described by a population-level reaction norm. Variation in reaction norms along environmental gradients may either intensify the envi- ronmental effects on timing (cogradient variation) or attenu- ate the effects (countergradient variation). To resolve spatial and seasonal variation in species’ response, we use a unique dataset of 91 taxa and 178 phenological events observed across a network of 472 monitoring sites, spread across the nations of the former Soviet Union. We show that compared to local rates of advancement of phenological events with the advancement of temperature-related cues (i.e., variation within site over years), spatial variation in reaction norms
  • Marjakangas, Emma-Liina; Abrego, Nerea; Grøtan, Vidar; de Lima, Renato A. F.; Bello, Carolina; Bovendorp, Ricardo S.; Culot, Laurence; Hasui, Érica; Lima, Fernando; Muylaert, Renata Lara; Niebuhr, Bernardo Brandão; Oliveira, Alexandre A.; Pereira, Lucas Augusto; Prado, Paulo I.; Stevens, Richard D.; Vancine, Maurício Humberto; Ribeiro, Milton Cezar; Galetti, Mauro; Ovaskainen, Otso (2020)
    Abstract Aim Forest fragmentation is among the principal causes of global biodiversity loss, yet how it affects mutualistic interactions between plants and animals at large spatial scale is poorly understood. In particular, tropical forest regeneration depends on animal-mediated seed dispersal, but the seed-dispersing animals face rapid decline due to forest fragmentation and defaunation. Here, we assess how fragmentation influences the pairwise interactions between 407 seed disperser and 1,424 tree species in a highly fragmented biodiversity hotspot. Location Atlantic Forest, South America. Methods We predicted interaction networks in 912 sites covering the entire biome by combining verified interaction data with co-occurrence probabilities obtained from a spatially explicit joint species distribution model. We identified keystone seed dispersers by computing a species-specific keystone index and by selecting those species belonging to the top 5% quantile. Results We show that forest fragmentation affects seed dispersal interactions negatively, and the decreased area of functionally connected forest, rather than increased edge effects, is the main driver behind the loss of interactions. Both the seed disperser availability for the local tree communities and in particular the proportion of interactions provided by keystone seed dispersers decline with increasing degree of fragmentation. Importantly, just 21 keystone species provided >40% of all interactions. The numbers of interactions provided by keystone and non-keystone species, however, were equally negatively affected by fragmentation, suggesting that seed dispersal interactions may not be rewired under strong fragmentation effects. Conclusions We highlight the importance of understanding the fragmentation-induced compositional shifts in seed disperser communities as they may lead to lagged and multiplicative effects on tree communities. Our results illustrate the utility of model-based prediction of interaction networks as well as model-based identification of keystone species as a tool for prioritizing conservation efforts. Similar modelling approaches could be applied to other threatened ecosystems and interaction types globally.