Ecology Letters

doi: 10.1111/ele.14047pmid: N/A

doi: 10.1111/ele.14045pmid: N/A

doi: 10.1111/ele.14049pmid: N/A

doi: 10.1111/ele.14051pmid: N/A

doi: 10.1111/ele.14042pmid: N/A

Driscoll, William W.; Wisecaver, Jennifer H.; Hackett, Jeremiah D.; Espinosa, Noelle J.; Padway, Jared; Engers, Jessica E.; Bower, Jessica A.

doi: 10.1111/ele.14172pmid: 36924044

Much of the evolutionary ecology of toxic algal blooms (TABs) remains unclear, including the role of algal toxins in the adaptive ‘strategies’ of TAB‐forming species. Most eukaryotic TABs are caused by mixotrophs that augment autotrophy with organic nutrient sources, including competing algae (intraguild predation). We leverage the standing diversity of TABs formed by the toxic, invasive mixotroph Prymnesium parvum to identify cell‐level behaviours involved in toxin‐assisted predation using direct observations as well as comparisons between genetically distinct low‐ and high‐toxicity isolates. Our results suggest that P. parvum toxins are primarily delivered at close range and promote subsequent prey capture/consumption. Surprisingly, we find opposite chemotactic preferences for organic (prey‐derived) and inorganic nutrients between differentially toxic isolates, respectively, suggesting behavioural integration of toxicity and phagotrophy. Variation in toxicity may, therefore, reflect broader phenotypic integration of key traits that ultimately contribute to the remarkable flexibility, diversity, and success of invasive populations.

Ardichvili, Alice Nadia; Loeuille, Nicolas; Dakos, Vasilis

doi: 10.1111/ele.14180pmid: 36893479

Ecosystems under stress may respond abruptly and irreversibly through tipping points. Although mechanisms leading to alternative stable states are much studied, little is known about how such ecosystems could have emerged in the first place. We investigate whether evolution by natural selection along resource gradients leads to bistability, using shallow lakes as an example. There, tipping points occur between two alternative states dominated by either submersed or floating macrophytes depending on nutrient loading. We model the evolution of macrophyte depth in the lake, identify the conditions under which the ancestor population diversifies and investigate whether alternative stable states dominated by different macrophyte phenotypes occur. We find that eco‐evolutionary dynamics may lead to alternative stable states, but under restrictive conditions. Such dynamics require sufficient asymmetries in the acquisition of both light and nutrient. Our analysis suggests that competitive asymmetries along opposing resource gradients may allow bistability to emerge by natural selection.

Beltran, Roxanne S.; Hernandez, Keith M.; Condit, Richard; Robinson, Patrick W.; Crocker, Daniel E.; Goetsch, Chandra; Kilpatrick, A. Marm; Costa, Daniel P.

doi: 10.1111/ele.14193pmid: 36888564

Although anthropogenic change is often gradual, the impacts on animal populations may be precipitous if physiological processes create tipping points between energy gain, reproduction or survival. We use 25 years of behavioural, diet and demographic data from elephant seals to characterise their relationships with lifetime fitness. Survival and reproduction increased with mass gain during long foraging trips preceding the pupping seasons, and there was a threshold where individuals that gained an additional 4.8% of their body mass (26 kg, from 206 to 232 kg) increased lifetime reproductive success three‐fold (from 1.8 to 4.9 pups). This was due to a two‐fold increase in pupping probability (30% to 76%) and a 7% increase in reproductive lifespan (6.0 to 6.4 years). The sharp threshold between mass gain and reproduction may explain reproductive failure observed in many species and demonstrates how small, gradual reductions in prey from anthropogenic disturbance could have profound implications for animal populations.

Gronchi, Enzo; Straile, Dietmar; Diehl, Sebastian; Jöhnk, Klaus D.; Peeters, Frank

doi: 10.1111/ele.14190pmid: 36870064

Climate warming alters the seasonal timing of biological events. This raises concerns that species‐specific responses to warming may de‐synchronize co‐evolved consumer‐resource phenologies, resulting in trophic mismatch and altered ecosystem dynamics. We explored the effects of warming on the synchrony of two events: the onset of the phytoplankton spring bloom and the spring/summer maximum of the grazer Daphnia. Simulation of 16 lake types over 31 years at 1907 North African and European locations under 5 climate scenarios revealed that the current median phenological delay between the two events varies greatly (20–190 days) across lake types and geographic locations. Warming moves both events forward in time and can lengthen or shorten the delay between them by up to ±60 days. Our simulations suggest large geographic and lake‐specific variations in phenological synchrony, provide quantitative predictions of its dependence on physical lake properties and geographic location and highlight research needs concerning its ecological consequences.

Walentowitz, Anna; Lenzner, Bernd; Essl, Franz; Strandberg, Nichola; Castilla‐Beltrán, Alvaro; Fernández‐Palacios, José María; Björck, Svante; Connor, Simon; Haberle, Simon G.; Ljung, Karl; Prebble, Matiu; Wilmshurst, Janet M.; Froyd, Cynthia A.; Boer, Erik J.; Nascimento, Lea; Edwards, Mary E.; Stevenson, Janelle; Beierkuhnlein, Carl; Steinbauer, Manuel J.;