Closing the Knowing-Doing Gap in Invasive Plant Management: Accessibility and Interdisciplinarity of Scientific Research

Like many conservation disciplines, invasion biology may suffer from a knowing-doing gap, where scientific research fails to inform management actions. We surveyed California resource managers to evaluate engagement with scientific research and to identify research priorities. We examined managers\u27 access to information, judgment of the usefulness of existing research, ability to generate scientific information, and priorities for future research. We found that practitioners rely on their own experience, and largely do not read the peer-reviewed literature, which they regard as only moderately useful. Less than half of managers who do research carry out experiments conforming to the norms of hypothesis testing, and their results are not broadly disseminated. Managers\u27 research needs are not restricted to applied science, or even basic ecology, but include social science questions. Scientists studying invasions can make their research more useful by crossing disciplinary boundaries, sourcing research questions from practitioners, and reporting results in accessible venues

Climate change\u27s impact on key ecosystem services and the human well-being they support in the US

Climate change alters the functions of ecological systems. As a result, the provision of ecosystem services and the well-being of people that rely on these services are being modified. Climate models portend continued warming and more frequent extreme weather events across the US. Such weather-related disturbances will place a premium on the ecosystem services that people rely on. We discuss some of the observed and anticipated impacts of climate change on ecosystem service provision and livelihoods in the US. We also highlight promising adaptive measures. The challenge will be choosing which adaptive strategies to implement, given limited resources and time. We suggest using dynamic balance sheets or accounts of natural capital and natural assets to prioritize and evaluate national and regional adaptation strategies that involve ecosystem services. © The Ecological Society of America

Trait Values, Not Trait Plasticity, Best Explain Invasive Species' Performance in a Changing Environment

<div><p>The question of why some introduced species become invasive and others do not is the central puzzle of invasion biology. Two of the principal explanations for this phenomenon concern functional traits: invasive species may have higher values of competitively advantageous traits than non-invasive species, or they may have greater phenotypic plasticity in traits that permits them to survive the colonization period and spread to a broad range of environments. Although there is a large body of evidence for superiority in particular traits among invasive plants, when compared to phylogenetically related non-invasive plants, it is less clear if invasive plants are more phenotypically plastic, and whether this plasticity confers a fitness advantage. In this study, I used a model group of 10 closely related <em>Pinus</em> species whose invader or non-invader status has been reliably characterized to test the relative contribution of high trait values and high trait plasticity to relative growth rate, a performance measure standing in as a proxy for fitness. When grown at higher nitrogen supply, invaders had a plastic RGR response, increasing their RGR to a much greater extent than non-invaders. However, invasive species did not exhibit significantly more phenotypic plasticity than non-invasive species for any of 17 functional traits, and trait plasticity indices were generally weakly correlated with RGR. Conversely, invasive species had higher values than non-invaders for 13 of the 17 traits, including higher leaf area ratio, photosynthetic capacity, photosynthetic nutrient-use efficiency, and nutrient uptake rates, and these traits were also strongly correlated with performance. I conclude that, in responding to higher N supply, superior trait values coupled with a moderate degree of trait variation explain invasive species' superior performance better than plasticity per se.</p> </div

Performance (RGR) of invasive and non-invasive species across nutrient treatments.

<p>Values are means ± standard error of invasive and non-invasive species groups in low-N and high-N treatment.</p

Trait reaction norms for invasive and non-invasive species across nutrient treatments.

<p>Dotted line  =  invasive species; solid line = non-invasive species. Trait abbreviations are as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0048821#pone-0048821-t001" target="_blank">Table 1</a>. For each trait, the line links the mean in the low-N treatment to the mean in the high-N treatment, so steeper slopes indicate greater relative responses to the change in nutrient supply.</p

Correlation of trait values and plasticity indices with performance.

<p>Trait abbreviations as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0048821#pone-0048821-t001" target="_blank">Table 1</a>. Pearson product-moment correlations (r) and p-values (p) for the relationship between mean trait values or mean plasticity index and mean RGR. Mean values are the average of the two nutrient treatments. The bottom three rows represent correlations between mean RGR and a combined plasticity index drawn from several traits (see text). Boldface denotes p-values less than.05; § denotes p-values significant at α = .05 when corrected for 17 multiple comparisons by the Benjamini-Hochberg procedure for individual traits or indices, and for 3 multiple comparisons for grouped plasticity indices. After elimination of an outlier for SMR plasticity (see text), the correlation coefficient r = .76557 and p = .0448 (non-significant).</p

Plasticity indices (PI_v) for invasive and non-invasive species.

<p>Trait abbreviations as in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0048821#pone-0048821-t001" target="_blank">Table 1</a>. Test statistics (t) and p-values (p) are from Student's t-test for unequal variances; p-values in boldface are <.05. The bottom three rows represent mean values for combined indices with several traits' plasticity indices averaged together by species (see also <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0048821#pone-0048821-g003" target="_blank">Figure 3</a>). No plasticity indices for individual traits were significantly different between invasive and non-invasive groups after Benjamini-Hochberg correction for 17 trait comparisons, nor were grouped indices significantly different after correction for three comparisons. Means, standard errors, and test statistics were calculated using the PI_v, which represents the absolute value of the change in trait value between N treatments, but a second index, the RTR, was used to determine the directionality of the response, which is indicated to the right of each PI_v column for individual traits. “Increase” means that all species in the group increased the trait value in response to increased N; “decrease” means that all species in the group decreased the trait value; and “mixed” means that at least one increase and one decrease were observed in the species group. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0048821#pone.0048821.s002" target="_blank">Table S2</a> in the Supplementary Information shows RTR values for all traits and all species.</p

Differences in mean plasticity between invasive and non-invasive species by trait grouping.

<p>Values are means ± standard error for invasive and non-invasive species, where the plasticity indices of several traits in a grouping have been averaged together for each of the 5 invasive and 5 non-invasive species. For the biomass allocation grouping, each species' value is its mean plasticity index for the traits LMR, SMR, RMR and LAR; for the leaf-level grouping, each species' value is its mean plasticity index for the traits SLA, DMF, P_area, N_area, chl_area, protein_area, A_area, and g_s; and for the whole-plant grouping, each species' value is its mean plasticity index for the traits PNUE, WUEi, SAR_N, and SAR_P. After correction for multiple comparisons, no differences were statistically significant.</p

Descriptions of traits and performance measure (fitness proxy).

<p>Descriptions of traits and performance measure (fitness proxy).</p