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836 results for “species limits”
Recruitment limitation for three tree species in BCI, Panama
<p><span>Recruitment limitation – the failure of a species to establish recruits at an available site – is a potential determinant of plant communities' structure, causing local communities to be a limited subset of the regional species pool. Recruitment limitation results from three mechanisms: i) lack of seed sources (i.e., source limitation), ii) failure of available seeds to reach recruitment sites (i.e., dispersal limitation), and iii) failure of arrived seeds to establish at a location (i.e., establishment limitation). Here, we evaluated the relative importance of these mechanisms in three co-occurring tree species (<i>Dipteryx oleifera, Attalea butyracea</i>,<i> </i>and <i>Astrocaryum standleyanum</i>) that share seed dispersers/predators. The study was set up on Barro Colorado Island (Panama) at 62 1-ha sites with varying tree densities. Source limitation was estimated as the proportion of sites that would be reached by seeds if seeds were distributed uniformly. Dispersal limitation was estimated from the number of sites with seeds in the soil bank. Establishment limitation was evaluated by measuring germination and 1-year survival in seed addition experiments. The effect of conspecific and heterospecific densities on the mechanisms was evaluated at three spatial scales (1, 5 and 9 ha). For all species, seed predation was the most important recruitment component (~80% decrease in seed survival). Establishment varied among species and was affected by conspecific and heterospecific species densities across spatial scales. Given that species identity, distribution and seed dispersal/predation affect recruitment at multiple scales, multiscale studies are required to understand how recruitment limitation determines community structure in tropical forests. </span></p>
Moving beyond the diversity paradox: the limitations of competition-based frameworks in understanding species diversity
<p>Over the last century, ecologists have attempted to understand patterns of species diversity by showing stable coexistence arising from a baseline expectation of competitive exclusion. This expectation stems from an explicit assumption of resource scarcity and implicit assumptions of Malthusian struggle and winner-take-all dynamics. Fidelity to the competitive exclusion principle (CEP) presents species diversity as a paradox: if species compete for limited resources, how can they coexist? In this essay, we investigate the contradiction between the theoretical expectation of competitive exclusion and the empirical prevalence of multispecies communities. We trace the persistence of the CEP in ecological research despite numerous challenges and explore publishing trends suggesting that this framework has resulted in a disproportionate focus on competition and exclusion in contemporary research. From a critical science studies perspective, we analyze the sociopolitical factors that have contributed to these patterns. We argue that we must excavate the ideological foundation upon which competition-based coexistence research has been built to move beyond the current perceived "diversity paradox." To that end, we propose shifting the functional null hypothesis of coexistence research, introducing the notion of a "coexistence principle," which positions the persistence of multispecies communities as the rule rather than the exception in nature.</p>
Fig. 2 in Interspecific Interactions as a Factor of Limitation of Geographical Distribution: Evidence Obtained by Modeling Home Ranges of Vole Twin Species Microtus Arvalis – M. Levis (Rodentia, Microtidae)
Fig. 2. Potential distribution of the East European vole (Microtus levis). Captions as in fig.1.
Data from: Species limits and introgression in Pimelodus from the Magdalena-Cauca River basin
<p>Low morphological differentiation among taxa hampers its appropriate identification, basic biological studies, and promotion of any conservation effort. Aiming to clarify the evolution and speciation among members of <i>Pimelodus </i>from the Magdalena-Cauca River basin, this study tested the hypothesis that <i>P. yuma, P. grosskopfii </i>and<i> P. crypticus</i> represent<i> </i>three independently evolving species and explored signals of interspecific hybridization. Likewise, we test the ancient hypothesis that the <i>trans</i>-Andean <i>Pimelodus yuma</i> and <i>P. crypticus</i> belong to the <i>cis</i>-Andean <i>P. blochii </i>species complex. The outcomes based on mitochondrial (<i>cox1</i>) and nuclear [RADseq (Illumina Hi-Seq), microsatellites and <i>rag2</i>] markers combined with coalescence-based and allele-frequency methods, confirm that each studied <i>trans</i>-Andean species represent<i> </i>an independently evolving unit. We used Stacks v.2.52 for <i>de novo</i> SNP genotyping. Contrary to expectations, <i>P. yuma </i>was<i> </i>found as a sister clade of <i>P. blochii</i>, while <i>P. crypticus </i>(confused for a long time with <i>P. blochii</i>) was phylogenetic closer to <i>P. grosskopfii</i>. Additionally, we found strong evidence of historical introgression between the non-sibling species <i>Pimelodus yuma </i>and<i> P. grosskopfii, </i>breaking the absence of interbreeding and the independent evolutionary trajectory among Trans-Andean <i>Pimelodus </i>during their diversification history, a pre-requisite to define species limits. However, non-significant values of current gene flow were evidenced between them, supporting the hypothesis of full isolation.</p>
Quantifying within-species trait variation in space and time reveals limits to trait-mediated drought response
<p>Climate change is stressing many forests around the globe, yet some tree species may be able to persist through acclimation and adaptation to new environmental conditions. The ability of a tree to acclimate during its lifetime through changes in physiology and functional traits, defined here as its acclimation potential, is not well known. We investigated the acclimation potential of trembling aspen (Populus tremuloides) and ponderosa pine (Pinus ponderosa) trees by examining within-species variation in drought response functional traits across both space and time, and how trait variation influences drought-induced tree mortality. We measured xylem tension, morphological traits, and physiological traits on mature trees in southwestern Colorado, USA across a climate gradient that spanned the distribution limits of each species and three years with large differences in climate. Trembling aspen functional traits showed high within-species variation, and osmotic adjustment and carbon isotope discrimination were key determinants for increased drought tolerance in dry sites and in dry years. However, trembling aspen trees at low elevation were pushed past their drought tolerance limit during the severe 2018 drought year, as elevated mortality occurred. Higher specific leaf area during drought was correlated with higher percentages of canopy dieback the following year. Ponderosa pine functional traits showed less within-species variation, though osmotic adjustment was also a key mechanism for increased drought tolerance. Remarkably, almost all traits varied more year-to-year than across elevation in both species. Our results shed light on the scope and limits of intraspecific trait variation for mediating drought responses in key southwestern US tree species and will help improve our ability to model and predict forest responses to climate change. </p>
Data from: Species recognition limits mating between hybridizing ant species
<p><span>Identifying mechanisms limiting hybridization is a central goal of speciation research. Here, we studied pre-mating and post-mating barriers to hybridization between two ant species, <em>Formica selysi</em> and <em>Formica cinerea</em>. These species hybridize in the Rhône valley in Switzerland, where they form a mosaic hybrid zone, with limited introgression from <em>F. selysi</em> into <em>F</em>. <em>cinerea</em>. There was no sign of temporal isolation between the two species in the production of queens and males. With choice experiments, we showed that queens and males strongly prefer to mate with conspecifics. Yet we did not detect post-mating barriers caused by genetic incompatibilities. Specifically, hybrids of all sexes and castes were found in the field and F1 hybrid workers did not show reduced viability compared to non-hybrid workers. To gain insights into the cues involved in species recognition, we analyzed the cuticular hydrocarbons of queens, males and workers and staged dyadic encounters between workers. Cuticular hydrocarbon profiles differed markedly between species, but were similar in <em>F. cinerea</em> and hybrids. Accordingly, workers also discriminated species, but they did not discriminate <em>F. cinerea</em> and hybrids. We discuss how the CHC-based recognition system of ants may facilitate the establishment of pre-mating barriers to hybridization, independent of hybridization costs.</span></p>
Phylogeographical break and limited connectivity between multiple refugia in panantarctic moss species
<p><span><strong>Aim</strong>:</span><span> Historical biogeography of the Antarctic terrestrial biota remains poorly studied and understood. We aim to advance this through a range-wide, multilocus analysis of a pan-Antarctic moss species, in the context of its age, range dynamics, phylogeographical structure, and location of possible long-term refugia. </span></p> <p><span><strong>Location</strong>:</span><span> Continental and maritime Antarctic, South America (Patagonia), Australasia.</span></p> <p><span><strong>Taxon</strong>:</span><span> <em>Syntrichia sarconeurum</em> Ochyra & R.H. Zander (Pottiaceae).</span></p> <p><span><strong>Methods</strong>:</span><span> We used a comprehensive, range-wide and taxonomically-informed sampling, and multilocus sequencing of nuclear and plastid DNA regions. Temporal evolutionary framework, regional genetic diversification and diversity were assessed with phylogenetic and phylogeographic reconstructions, molecular dating, haplotype networks, mismatch analysis, and S-DIVA reconstruction of past events and ancestral areas.</span></p> <p><span><strong>Results</strong>:</span><span> Intercontinental disjunction between Australia and Antarctica/S. America was dated to 3.77 Ma, while diversification of extant <em>Syntrichia sarconeurum</em> lineages had taken place since roughly 1.36 Ma. Antarctic populations contained two high-frequency, allopatric cpDNA haplotypes, which highlighted separation of the continental populations. <em>ITS</em> data showed higher diversification and revealed three main lineages with a main genetic break mostly concordant with plastid data. <em>ITS</em> also showed contrasting diversity between the Antarctic continent and maritime Antarctic/Patagonia.</span></p> <p><span><strong>Main conclusions</strong>:</span><span> Age of the Antarctic range of <em>Syntrichia sarconeurum</em> potentially reaches back to mid-Pliocene, while diversification of extant genetic lineages was linked with recurrent macroenvironmental changes of the Pleistocene. Significant phylogeographical structure displays a major genetic break, which coincides with a known boundary in the terrestrial biota and suggests constrained population connectivity. <em>S. sarconeurum</em> persisted <em>in situ</em> over several glacial periods in refugia both in the peripheral maritime Antarctic and within the Antarctic continent. Disparity in genetic diversity among these areas hypothetically reflects asymmetric changes of reproduction mode in the past. Finally, nested topology of Patagonian subclades and ancestry analysis indicates that South American populations were secondary and originated through multiple dispersal from the Antarctic region.</span></p>
TABLE 1 in Species limits in the African Palm Swift Cypsiurus parvus
<p>TABLE 1 Means and standard deviations of length of wing and tail (see text) of taxa of African Palm Swift <i>Cypsiurus parvus</i> (males alone). * indicates Malagasy taxa.</p><table><tbody><tr><th><b>taxon</b></th><th><b>sample</b></th><th><b>mean wing</b></th><th><b>S.D.</b></th><th><b>mean tail</b></th><th><b>S.D.</b></th></tr></tbody><tbody><tr><th>parvus</th><td>14</td><td>129.4</td><td>3.61</td><td>93.3</td><td>4.41</td></tr><tr><th>brachypterus</th><td>10</td><td>124</td><td>3.41</td><td>92.2</td><td>3.03</td></tr><tr><th>myochrous</th><td>10</td><td>126.5</td><td>4.04</td><td>94.1</td><td>4.86</td></tr><tr><th>laemostigma</th><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><th>hyphaenes</th><td>1</td><td>131</td><td>—</td><td>88</td><td>—</td></tr><tr><th>celer</th><td>—</td><td>—</td><td>—</td><td>—</td><td>—</td></tr><tr><th>*griveaudi</th><td>5</td><td>127</td><td>2.92</td><td>81.4</td><td>1.52</td></tr><tr><th><i>*gracilis</i></th><td>27</td><td>120.9</td><td>3.20</td><td>78.0</td><td>4.13</td></tr></tbody></table>
TABLE 2 in Species limits in the African Palm Swift Cypsiurus parvus
<p>TABLE 2 Means and standard deviations of length of wing and tail of African and Malagasy taxa of African Palm Swift <i>Cypsiurus parvus</i> from Table 1.</p><table><tbody><tr><th></th><th><i>n</i></th><th><b>wing</b></th><th><b>tail</b></th></tr></tbody><tbody><tr><th>African <i>Cypsiurus</i></th><td>35</td><td>127.1 ± 4.26</td><td>93.1 ± 4.21</td></tr><tr><th>Malagasy <i>Cypsiurus</i></th><td>32</td><td>121.8 ± 3.85</td><td>78.5 ± 4.02</td></tr></tbody></table>
TABLE 3 in Taxonomic status of the Western Hemispingus Sphenopsis ochracea (Thraupidae) and a review of species limits in the genus Sphenopsis P. L. Sclater, 1861
<p>TABLE 3</p><table><thead><tr><th>Sex</th><th><b>Species</b></th><th><i>n</i></th><th>WG</th><th>TR</th><th>TL</th><th>BL</th><th><b>BW</b></th></tr></thead><tbody><tr><th>female</th><td><i>S. melanotis melanotis</i></td><td>5</td><td>73.2 ± 1.6</td><td>19.9 ± 0.3</td><td>62.8 ± 2.4</td><td>8.2 ± 0.3</td><td>3.9 ± 0.1</td></tr><tr><th></th><td><i>S. m. castaneicollis</i></td><td>3</td><td>61.7 ± 1.5</td><td>21.3 ± 2.1</td><td>55.0 ± 2.8</td><td>7.6 ± 0.4</td><td>3.7 ± 0.3</td></tr><tr><th></th><td><i>S. frontalis frontalis</i></td><td>5</td><td>69.5 ± 2.8</td><td>19.4 ± 0.8</td><td>61.0 ± 4.0</td><td>8.3 ± 0.1</td><td>3.5 ± 0.0</td></tr><tr><th></th><td><i>S. f. hanieli</i></td><td>0</td><td>–</td><td>–</td><td>–</td><td>–</td><td>–</td></tr><tr><th></th><td><i>S. piurae</i></td><td>1</td><td>68</td><td>21.7</td><td>61</td><td>8.8</td><td>3.2</td></tr><tr><th></th><td><i>S. ochracea</i></td><td>1</td><td>67</td><td>23.5</td><td>56</td><td>8.4</td><td>4.1</td></tr><tr><th>male</th><td><i>S. m. melanotis</i></td><td>2</td><td>75.0 ± 2.8</td><td>19.5 ± 0.1</td><td>63.0 ± 5.7</td><td>8.4 ± 0.4</td><td>4.1 ± 0.4</td></tr><tr><th></th><td><i>S. m. castaneicollis</i></td><td>6</td><td>69.3 ± 1.5</td><td>21.1 ± 1.4</td><td>60.0 ± 1.8</td><td>7.8 ± 0.5</td><td>3.7 ± 0.2</td></tr><tr><th></th><td><i>S. f. frontalis</i></td><td>6</td><td>73.7 ± 3.4</td><td>19.4 ± 1.4</td><td>62.7 ± 2.4</td><td>8.5 ± 0.1</td><td>3.5 ± 0.1</td></tr><tr><th></th><td><i>S. f. hanieli</i></td><td>1</td><td>70</td><td>19.9</td><td>–</td><td>8.5</td><td>3.5</td></tr><tr><th></th><td><i>S. piurae</i></td><td>3</td><td>70.0 ± 0.0</td><td>21.9 ± 1.5</td><td>63.3 ± 5.8</td><td>8.7 ± 0.0</td><td>3.4 ± 0.1</td></tr><tr><th></th><td><i>S. ochracea</i></td><td>3</td><td>72.5 ± 0.7</td><td>22.2 ± 0.1</td><td>60.5 ± 0.7</td><td>9.1 ± 0.0</td><td>4.2 ± 0.0</td></tr></tbody></table>
Resources do not limit compensatory response of a tallgrass prairie plant community to the loss of a dominant species
<p>The effect of species loss on ecosystem productivity is determined by both the functional contribution of the species lost, and the response of the remaining species in the community. According to the mass-ratio hypothesis, the loss of a dominant plant species, which has a larger proportionate contribution to productivity, is expected to exert an overwhelming effect on this important ecosystem function. However, via competitive release, loss of a dominant species can provide the opportunity for other plant species to establish, thrive and become abundant in the community, potentially compensating for the function lost. Furthermore, if resource limitation is removed, then compensatory response of function to the loss of a dominant species should be greater and more rapid than if resources are more limiting.</p> <p>To evaluate how resources may limit compensation of aboveground productivity to the loss of a dominant plant species, we experimentally removed the C<sub>4</sub> perennial tallgrass, <em>Andropogon gerardii</em>, from intact plant communities. We added water for four years, as well as nitrogen in the fourth year, to test the effect of resource limitation on the compensatory response.</p> <p>Overall, aboveground biomass production increased in the remaining community with both water and nitrogen addition. However, this increase in biomass production was not sufficient to fully compensate for the loss of A. gerardii, indicating water and nitrogen were not limiting short-term compensation in this community.</p> <p>Following the removal of the dominant species, there was a reordering of species abundances in the community, rather than changes in species richness. The C<sub>4</sub> grass <em>Bouteloua curtipendula</em> was the most responsive species, increasing by 57.9% in abundance with water addition and 91.0% with both water and nitrogen addition. Despite this dramatic increase in abundance, its short stature and lower per capita biomass production prevented this species from compensating for the loss of <em>A. gerardii</em>.</p> <p>Our results suggest that short-term compensation after the loss of a dominant plant species can be hastened by increased resource availability, but ultimately full compensation appears to be limited by the presence and abundance of species in the remaining community that possess traits that allow them compensate for the species lost.</p>
Data from: Within-species trait variation can lead to size limitations in seed dispersal of small-fruited plants
<p>The inability of small-gaped animals to consume very large fruits may limit seed dispersal of the respective plants. This has often been shown for large-fruited plant species that remain poorly dispersed when large-gaped animal species are lost due to anthropogenic pressure. Little is known about whether gape-size limitations similarly influence seed dispersal of small-fruited plant species that can show a large variation in fruit size within species.</p> <p>In this study, fruit sizes of 15 plant species were compared with the gape sizes of their 41 animal dispersers in the temperate, old-growth Białowieża Forest, Poland. The effect of gape-size limitations on fruit consumption was assessed at the plant species level, and for a subset of nine plant species, also at the individual level, and subindividual level (i.e., fruits of the same plant individual). In addition, for the species subset, fruit-seed trait relationships were investigated to determine whether a restricted access of small-gaped animals to large fruits results in the dispersal of fewer or smaller seeds per fruit.</p> <p>Fruit sizes widely varied among plant species (74.2%), considerably at the subindividual level (17.1%), and to the smallest extent among plant individuals (8.7%). Key disperser species should be able to consume fruits of all plant species and all individuals (except those of the largest-fruited plant species), even if they are able to consume only 28-55% of available fruits. Fruit and seed traits were positively correlated in eight out of nine plant species, indicating that gape size limitations will result in 49% fewer (in one plant species) or 16-21% smaller seeds (in three plant species) dispersed per fruit by small-gaped than by large-gaped main dispersers, respectively.</p> <p>Our results show that a large subindividual variation in fruit size is characteristic for small-fruited plant species, and increases their connectedness with frugivores at the level of plants species and individuals. Simultaneously, however, the large variation in fruit size leads to gape-size limitations that may induce selective pressures on fruit size if large-gaped dispersers become extinct. This study emphasizes the mechanisms by which gape-size limitation at the species, individual and subindividual level shape plant-frugivore interactions and the co-evolution of small-fruited plants.</p>
Spatial distribution and its limiting environmental factors of native orchid species diversity in the Beipan River Basin of Guizhou Province, China
<p>Understanding the distribution of biodiversity and its determinants, particularly that of ecologically sensitive ones, has long been intriguing to the science community and will help formulate conservation strategies under future climate changes. To this end, we conducted extensive field surveys on the distribution of orchid flora in the Beipan River Basin in Guizhou Province, which is one of the biodiversity conservation priorities in China. The data we acquired, together with those published previously, were converted into orchid species richness for each of the 3km × 3km grid cells covering the study region. Redundancy analysis (RDA) and Geographically Weighted Regression (GWR) were then applied to determine which of the 30 environmental factors are potentially critical for the spatial distribution of orchid flora we have observed. Despite a moderate spatial extent, we found that the Beipan River Basin harbors about 249 native orchid species belonging to 74 genera, equivalent to 14.5% of orchid flora of China. Orchid species richness in this area follows a descending gradient from the southeast to the northwest, 70.41% of its variation among grid cells can be explained by environmental factors and spatial variables, and spatial variables accounted for 63.90% of the spatial variation of orchid distribution, indicating that spatial variables played a dominant role in the distribution of wild orchidaceae species richness. In addition, the main environmental driver is the mean temperature of the wettest quarter. Our study provides a good example for revealing the main drivers of orchid distribution characteristics, and has a certain reference value for the development of orchid conservation strategies.</p>
Data for: Phosphorus limitation of early growth differs between nitrogen-fixing and non-fixing dry tropical forest tree species
<p>Tropical forests are often characterized by low soil phosphorus (P) availability, suggesting that P limits plant performance. However, how seedlings from different functional types respond to soil P availability is poorly known but important for understanding and modeling forest dynamics under changing environmental conditions.</p> <p>We grew four nitrogen (N)-fixing Fabaceae and seven diverse non-N-fixing tropical dry forest tree species in a shade house under three P fertilization treatments, and evaluated carbon (C) allocation responses, P demand, P-use, investment in P acquisition traits, and correlations among P acquisition traits.</p> <p>N-fixers grew larger with increasing P addition in contrast to non-N-fixers, which showed fewer responses in C allocation and P-use. Foliar P increased with P addition for both functional types, while P acquisition strategies did not vary among treatments but differed between functional types, with N-fixers showing higher root phosphatase activity (RPA) than non-fixers.</p> <p>Growth responses suggest that N-fixers are limited by P, but non-fixers may be limited by other resources. However, regardless of limitation, P acquisition traits such as mycorrhizal colonization and RPA were non-plastic across a steep P gradient. Differential limitation among plant functional types has implications for forest succession and earth system models.</p>
Acclimation limits for embolism resistance and osmotic adjustment accompany the geographic dry edge of Mediterranean species
<p>Survival and growth of woody species in the Mediterranean are mainly restricted by water availability. We tested the hypothesis that Mediterranean species acclimate their xylem vulnerability and osmotic potential along a precipitation gradient.</p> <p>We studied five predominant co-occurring Mediterranean species; <em>Quercus calliprinos</em>, <em>Pistacia palaestina</em>, <em>Pistacia lentiscus</em>, <em>Rhamnus lycioides</em>, and <em>Phillyrea latifolia</em>, over two summers at three sites. The driest of the sites is the distribution edge for all the five species. We measured key hydraulic and osmotic traits related to drought resistance, including resistance to embolism (<span class="None">Ψ<sub>50)</sub></span> and the seasonal dynamics of water and osmotic potentials.</p> <p>The leaf water potentials (<span class="None">Ψ<sub>1</sub></span>) of all species declined significantly along the summer, reaching significantly lower <span class="None">Ψ<sub>l</sub></span> at the end of summer in the drier sites. Surprisingly, we did not find plasticity along the drought gradient in <span class="None">Ψ<sub>50</sub></span> or osmotic potentials. This resulted in much narrower hydraulic safety margins (HSM) in the drier sites, where some species experienced significant embolism.</p> <p>Our analysis indicates that reduction in HSM to null values put Mediterranean species in embolism risk as they approach their hydraulic limit near the geographic dry edge of their distribution.</p>
Consilience across multiple, independent genomic data sets reveals species in a complex with limited phenotypic variation
<p>Species delimitation in the genomic era has focused predominantly on the application of multiple analytical methodologies to a single massive parallel sequencing (MPS) data set, rather than leveraging the unique but complementary insights provided by different classes of MPS data. In this study we demonstrate how the use of two independent MPS data sets, a sequence capture data set and a single nucleotide polymorphism (SNP) data set generated via genotyping-by-sequencing, enables the resolution of species in three complexes belonging to the grass genus <em>Ehrharta, </em>whose strong population structure and subtle morphological variation limit the effectiveness of traditional species delimitation approaches. Sequence capture data are used to construct a comprehensive phylogenetic tree of <em>Ehrharta </em>and to resolve population relationships within the focal clades, while SNP data are used to detect patterns of gene pool sharing across populations, using a novel approach that visualises multiple values of K. Given that the two genomic data sets are fully independent, the strong congruence in the clusters they resolve provides powerful ratification of species boundaries in all three complexes studied. Our approach is also able to resolve a number of single-population species and a probable hybrid species, both which would be difficult to detect and characterize using a single MPS data set. Overall, the data reveal the existence of 11 and five species in the <em>E. setacea</em> and <em>E. rehmannii </em>complexes, with the <em>E. ramosa</em> complex requiring further sampling before species limits are finalized. Despite phenotypic differentiation being generally subtle, true crypsis is limited to just a few species pairs and triplets. We conclude that, in the absence of strong morphological differentiation, the use of multiple, independent genomic data sets is necessary in order to provide the cross-data set corroboration that is foundational to an integrative taxonomic approach.</p>
Seed limitation interacts with biotic and abiotic factors to constrain novel species' impact on community biomass and richness
<p>Seed limitation can narrow down the number of coexisting plant species, limit plant community productivity, and can also constrain community responses to changing environmental and biotic conditions. In a 10-year full-factorial experiment of seed addition, fertilisation, warming, and herbivore exclusion, we tested how seed addition alters community richness and biomass, and how its effects depend on seed origin and biotic and abiotic context. We found that seed addition increased species richness in all treatments, and increased plant community biomass depending on nutrient addition and warming. Novel species, originally absent from the communities, increased biomass the most, especially in fertilised plots and in the absence of herbivores, while adding seeds of local species did not affect biomass. Our results show that seed limitation constrains both community richness and biomass, and highlight the importance of considering trophic interactions and soil nutrients when assessing novel species immigrations and their effects on community biomass.</p>
Large leaf hydraulic safety margins limit the risk of drought-induced leaf hydraulic dysfunction in Neotropical rainforest canopy tree species
<p>The sequence of key water potential thresholds from the onset of water stress to mortality, and the timing of stomatal closure with regard to leaf xylem embolism formation are essential to characterizing plant adaptive strategies to drought. This constitutes a critical knowledge gap for tropical rainforest species, which may be less vulnerable to drought than previously thought.</p> <p>We recorded key leaf and stem water potential thresholds, leaf hydraulic safety margins (HSMleaf), leaf stomatal safety margins (SSMleaf) and estimated native embolism levels during a normal-intensity dry season across 18 Neotropical rainforest tree species. We also solved a sequence of key water potential thresholds. Additionally, we provide a cross-biome analysis of SSMleaf encompassing 97 species from four major biomes based on a literature survey.</p> <p>In the studied rainforest species, leaf turgor loss point, used as a surrogate for stomatal closure, typically occurred before the onset of leaf xylem embolism. Most species exhibited positive HSMleaf and SSMleaf, with contrasting values across species and nearly absent embolism levels during the dry season irrespective of the experienced midday leaf water potentials. Our results point out that leaf xylem embolism is not routine for Neotropical rainforest tree species.</p> <p>Based on our proposal of the water potential sequence for tropical rainforest trees, we argue that leaf xylem embolism is a rare event for these species. This was supported by the literature survey, indicating that across biomes, most woody species have rather large SSM<sub>leaf</sub> and that leaves of tropical rainforest trees are not necessarily more vulnerable than in other biomes. However, we found evidence that some tropical rainforest species may be more vulnerable than others to ongoing climate change. Our data provide an opportunity to parametrize tree-based or land-surface models for tropical rainforests.</p>
Plant–hummingbird pollination networks exhibit limited rewiring after experimental removal of a locally abundant plant species
<p>In this study, we simulated the local extinction of a hummingbird-pollinated understory plant, <em>Heliconia</em> <em>tortuosa</em>, from tropical forest fragments using a replicated Before-After-Control-Impact (BACI) experimental design while quantifying plant-hummingbird interactions through two parallel techniques: pollen collected from individual hummingbirds ('pollen networks', created from >300 pollen samples) and observations of hummingbirds visiting focal plants ('camera networks', created from >19,000 observation hours). Each response variable was measured during each experimental period (pre and post) in sites with and without <em>H. tortuosa</em> removal (treatment and control).</p>
Data for paper: Genomic data reveals new species and the limits of mtDNA barcode diagnostics to contain a global pest species complex (Diptera: Tephritidae: Dacinae)
<p>Files in this repository:</p><p>"COI_alignment.fas.zip" Zipped file of the FASTA alignment of the COI sequences.</p><p>"COI_IQtree.treefile" Newick treefile resulting from the IQ-tree analysis of the COI alignment.</p><p>"RAD-loci_alignment.nex.zip" Zipped file of the NEXUS alignment of RAD loci of 2295 samples.</p><p>"RAD-loci_IQtree.tre" Newick treefile resulting from the IQ-tree analysis of the RAD-loci alignment.</p><p>"RAD-SNP_alignment.usnps.nex" NEXUS alignment of the RAD-SNP data of 50 samples.</p><p>"RAD-SNP_SNAPP.trees" Set of Newick trees resulting from the BEAST SNAPP analysis.</p>
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Allen Brain Atlas
Allen Brain Atlas is an Allen Institute collection of brain map atlases, datasets, APIs, and analysis tools covering mouse, human, and non-human primate brain resources.
Annotated Behaviour and Observability Dataset (ABODe)
ABODe is a University of Edinburgh DataShare dataset for behavior classification in group-housed mice using home-cage video, identities, bounding boxes, ground-plate positions, and annotator labels.
DANDI Archive for NWB datasets
DANDI is a BRAIN Initiative archive for publishing and sharing neurophysiology data, including electrophysiology, optophysiology, and behavioral data packaged as NWB and related standards.
International Brain Laboratory public data
The International Brain Laboratory public data releases expose standardized mouse decision-making experiments, including Neuropixels recordings, widefield calcium imaging, behavior, and session metadata accessed through the ONE API.
OpenNeuro
OpenNeuro is a free, open platform for sharing neuroimaging datasets, with public search, dataset pages, and download paths for web, S3, DataLad, and the OpenNeuro CLI.