Limits to species distributions on tropical mountains shift from high temperature to competition as elevation increases

Species turnover with elevation is a widespread phenomenon and provides valuable information on why and how ecological communities might reorganize as the climate warms. It is commonly assumed that species interactions are more likely to set warm range limits, while physiological tolerances determine cold range limits. However, most studies are from temperate systems and rely on correlations between thermal physiological traits and range limits; little is known about how physiological traits and biotic interactions change simultaneously along continuous thermal gradients. We used a combination of correlational and experimental approaches to investigate communities of Drosophila flies in rainforests of the Australian Wet Tropics, where there is substantial species turnover with elevation. Our experiments quantified individual-level and population-level responses to temperature, as well as the impact of interspecific competition under different temperature regimes. Species' distributions were better explained by their performance at extreme temperatures than by their thermal optima. Upper thermal limits varied less among species than lower thermal limits. Nonetheless, these small differences were associated with differences in the centered elevation of distribution. Low-elevation species were not those with the lowest tolerance to cold, suggesting that cold temperatures were not limiting their abundance at high elevations. Instead, under upland temperature regimes, abundances of these low-elevation species were reduced by competition with a high-elevation species, in both short- and long-term competition experiments. Our results demonstrate that high-elevation species are confined to their current ranges by high temperatures at lower elevations, indicating that their ranges will be highly sensitive to future warming. Counter to expectation, species interactions strongly influenced community composition at cooler, high-elevation sites. Together, these results raise the possibility that tropical communities differ from better-studied temperate communities in terms of the relative importance of biotic interactions and abiotic factors in shaping community composition and how the impact of these factors will change as temperatures increase

Approximations of Continuous Newton\u27s Method: An Extension of Cayley\u27s Problem

Continuous Newton\u27s Method refers to a certain dynamical system whose associated flow generically tends to the roots of a given polynomial. An Euler approximation of this system, with step size h=1, yields the discrete Newton\u27s method algorithm for finding roots. In this note we contrast Euler approximations with several different approximations of the continuous ODE system and, using computer experiments, consider their impact on the associated fractal basin boundaries of the root

Antagonistic interaction networks are structured independently of latitude and host guild

Peer reviewe

The genome sequence of the broken-barred carpet, Electrophaes corylata (Thunberg, 1792)

We present a genome assembly from an individual male Electrophaes corylata (the Broken-barred Carpet; Arthropoda; Insecta; Lepidoptera; Geometridae). The genome sequence is 347.5 megabases in span. Most of the assembly is scaffolded into 30 chromosomal pseudomolecules, including the Z sex chromosome. The mitochondrial genome has also been assembled and is 16.36 kilobases in length. Gene annotation of this assembly on Ensembl identified 16,031 protein coding genes

The genome sequence of the small angle shades, Euplexia lucipara (Linnaeus, 1758)

We present a genome assembly from an individual male Euplexia lucipara (the Small Angle Shades; Arthropoda; Insecta; Lepidoptera; Noctuidae). The genome sequence is 661.8 megabases in span. Most of the assembly is scaffolded into 31 chromosomal pseudomolecules, including the Z sex chromosome. The mitochondrial genome has also been assembled and is 15.37 kilobases in length. Gene annotation of this assembly on Ensembl identified 20,395 protein coding genes

The genome sequence of the pebble hook-tip, Drepana falcataria (Linnaeus, 1758)

We present a genome assembly from an individual male Drepana falcataria (the Pebble Hook-tip; Arthropoda; Insecta; Lepidoptera; Drepanidae). The genome sequence is 326.7 megabases in span. The whole assembly is scaffolded into 31 chromosomal pseudomolecules, including the assembled Z sex chromosome. The mitochondrial genome has also been assembled and is 15.4 kilobases in length

The genome sequence of the red twin-spot carpet, Xanthorhoe spadicearia (Denis & Schiffermüller, 1775)

We present a genome assembly from an individual female Xanthorhoe spadicearia (the Red Twin-spot Carpet; Arthropoda; Insecta; Lepidoptera; Geometridae). The genome sequence is 276.7 megabases in span. Most of the assembly is scaffolded into 31 chromosomal pseudomolecules, including the Z sex chromosome. The mitochondrial genome has also been assembled and is 17.03 kilobases in length. Gene annotation of this assembly on Ensembl identified 16,396 protein coding genes

The genome sequence of the twin-spotted quaker, Anorthoa munda (Denis & Schiffermüller, 1775)

We present a genome assembly from an individual male Anorthoa munda (the Twin-spotted Quaker; Arthropoda; Insecta; Lepidoptera; Noctuidae). The genome sequence is 938.6 megabases in span. Most of the assembly is scaffolded into 27 chromosomal pseudomolecules, including the Z sex chromosome. The mitochondrial genome has also been assembled and is 15.33 kilobases in length. Gene annotation of this assembly on Ensembl identified 22,894 protein coding genes

The genome sequence of the marbled white spot, Protodeltote pygarga (Hufnagel, 1766)

We present a genome assembly from an individual male Protodeltote pygarga (the Marbled White Spot; Arthropoda; Insecta; Lepidoptera; Noctuidae). The genome sequence is 421.1 megabases in span. Most of the assembly is scaffolded into 31 chromosomal pseudomolecules, including the Z sex chromosome. The mitochondrial genome has also been assembled and is 15.48 kilobases in length. Gene annotation of this assembly on Ensembl identified 17,784 protein coding genes

The genome sequence of the scorched carpet, Ligdia adustata (Denis & Schiffermüller, 1775)

We present a genome assembly from an individual female Ligdia adustata (the Scorched Carpet; Arthropoda; Insecta; Lepidoptera; Geometridae). The genome sequence is 399.7 megabases in span. Most of the assembly is scaffolded into 31 chromosomal pseudomolecules, including the Z sex chromosome. The mitochondrial genome has also been assembled and is 15.43 kilobases in length. Gene annotation of this assembly on Ensembl identified 17,979 protein coding genes