Species distribution models (SDMs) have been criticized for involving assumptions that ignore or categorize many ecologically relevant factors such as dispersal ability and biotic interactions. Another potential source of model error is the assumption that species are ecologically uniform in their climatic tolerances across their range. Typically, SDMs treat a species as a single entity, although populations of many species differ due to local adaptation or other genetic differentiation. Not taking local adaptation into account may lead to incorrect range prediction and therefore misplaced conservation efforts. A constraint is that we often do not know the degree to which populations are locally adapted. Lacking experimental evidence, we still can evaluate niche differentiation within a species' range to promote better conservation decisions. We explore possible conservation implications of making type I or type II errors in this context. For each of two species, we construct three separate Max-Ent models, one considering the species as a single population and two of disjunct populations. Principal component analyses and response curves indicate different climate characteristics in the current environments of the populations. Model projections into future climates indicate minimal overlap between areas predicted to be climatically suitable by the whole species vs. population-based models. We present a workflow for addressing uncertainty surrounding local adaptation in SDM application and illustrate the value of conducting population-based models to compare with whole-species models. These comparisons might result in more cautious management actions when alternative range outcomes are considered.

Host use and selection by herbivores are often determined by host chemistry. Lichen secondary chemicals frequently have been assumed to have a defensive role against herbivores similar to that of higher plants, but thus far there is only circumstantial evidence of the adverse effect of lichen secondary chemicals on specialized lichen‐feeders. We studied the impact of lichen secondary metabolites on performance and host preference of lichenivorous larvae of the moth Eilema depressum using a recently developed manipulation method that allows the removal of a major part of lichen secondary metabolites from the extracellular space of the lichen thallus without harming their primary metabolism. All larvae died on intact thalli of Vulpicida pinastri and Hypogymnia physodes, whereas, after extraction of most of the lichens' secondary chemicals (e.g., pinastric and physodic acids, respectively), survival of neonate larvae ranged between 75% and 85%. In turn, atranorin, the major secondary metabolite in the cortical layer of Parmelia sulcata, merely retarded the growth of larvae during their first days, but had no long‐term impact on survival or performance of larvae. In preference experiments, treated thalli with lowered concentrations of lichen secondary metabolites, with the exception of Xanthoria parietina, were preferred to intact thalli containing secondary chemicals. Our results show that lichen secondary metabolites may act, at natural concentrations, as strong antiherbivore compounds against E. depressum larvae and may play an important role in their host selection.

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The relationship between precipitation chemistry and the concentrations of nitrogen ([N]) and phosphorus ([P]) in the cushion-forming lichen Cladonia portentosa (Dufour) Coem. (l C. impexa (Harm)) was investigated. Samples of C. portentosa were collected from heathlands and upland moorlands close to 31 rural sampling stations in the UK Acid Deposition Monitoring Network, which provides data on wet deposition and NO # concentrations in air. The [N] and [P] were measured in the top 5 mm of lichen thalli (thallus apices) and also in a horizontal stratum between 40-50 mm from the apices (thallus base). The [N] (per unit dry mass) was 0n08-1n82 % and [P] was 0n04-0n17 %, depending on collection site and lichen fraction analysed. Concentrations of both elements were c. 2-5 times greater in the apices than in the basal strata, and [N] and [P] values in each stratum were strongly positively correlated. Lichen [N] was positively correlated with N deposition : this relationship was stronger when using [N] values for thallus bases than for the apices. By contrast, thallus [N] was poorly correlated with [N] values in precipitation. When [NO # ] in air was included together with NO $ − deposition in a linear regression model explaining thallus base N, the model fit was significantly improved, whereas modelled values of NH $ deposition rate for the heathland sites did not correlate with lichen [N]. It is suggested that the proportionately greater enrichment of [N] in the thallus base might reflect a perturbation of internal recycling of thallus N at polluted sites. Thallus [P] was generally weakly linked to wet N deposition but positively correlated with [NO # ] in air. It is not known whether the trend for increasing thallus [P] values indicates decreasing lichen growth rate and reduced growth dilution of P in polluted areas, or is due to regional variation in P deposition rate.

Intentional moving of species threatened by climate change is actively being discussed as a conservation approach. The debate, empirical studies, and policy development, however, are impeded by an inconsistent articulation of the idea. The discrepancy is demonstrated by the varying use of terms, such as assisted migration, assisted colonisation, or managed relocation, and their multiple definitions. Since this conservation approach is novel, and may for instance lead to legislative changes, it is important to aim for terminological consistency. The objective of this study is to analyse the suitability of terms and definitions used when discussing the moving of organisms as a response to climate change. An extensive literature search and review of the material (868 scientific publications) was conducted for finding hitherto used terms (N = 40) and definitions (N = 75), and these were analysed for their suitability. Based on the findings, it is argued that an appropriate term for a conservation approach relating to aiding the movement of organisms harmed by climate change is assisted migration defined as follows: Assisted migration means safeguarding biological diversity through the translocation of representatives of a species or population harmed by climate change to an area outside the indigenous range of that unit where it would be predicted to move as climate changes, were it not for anthropogenic dispersal barriers or lack of time. The differences between assisted migration and other conservation translocations are also discussed. A wide adoption of the clear and distinctive term and definition provided would allow more focused research on the topic and enable consistent implementation as practitioners could have the same understanding of the concept.

Summary1 Patterns of biomass allocation to sexual and vegetative reproduction were examined in a perennial stoloniferous clonal plant, Potentilla anserina (L.) Rydb. ssp. egedii (Wormsk.) Hiitonen, in relation to intraspecific competition between monoclonal and multiclonal ramets. 2 We predicted that a lack of competition would generate allocation to rapid, shortdistance spread (vegetative propagation), while the presence of competition would increase allocation to long-distance dispersal (sexual reproduction), and that the allocation shift would be more pronounced where the competing ramets were related. 3 P. anserina ramets were grown in a glasshouse in small pots, either alone (no competition) or with a size-matched ramet that originated from the same clone (within-genet competition) or a different one (between-genet competition). 4 Competition suppressed both growth and reproduction, but there was no treatment response in relative investment at the level of a whole genet, although both mother ramets and their daughters showed clear effects when analysed separately. 5 When experiencing competition, the mother ramet allocated relatively more to flowers, whereas allocation to vegetative growth was more intense when competition was absent. Allocation patterns were independent of the relatedness of competitors. 6 The results imply that P. anserina can modify the allocation of resources to different life-history traits according to competitive stress. Such flexibility is likely to reflect a shift in the optimal allocation strategy during the life cycle of a plant with a guerilla growth form with rapid exploitation of free space in a new patch by vegetative spread favoured. When spread becomes limited by competition, long-distance dispersal in space (seeds) or time (persistence) becomes beneficial.

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J. 2000. Phenols in reproductive and somatic structures of lichens: a case of optimal defence? -Oikos 91: 371-375.Optimal defence theory (ODT) attempts to explain variation in plant secondary compounds between different species, different growth conditions and different parts of individual plants. The theory is widely applied to vascular plants and more recently also to seaweeds. Surprisingly, ODT has gained little attention as potential explanation on the distribution of lichen secondary metabolites. In the present study, we analysed intrathalline variation in total phenol content and phenol spectra between reproductive and somatic structures of three foliose lichens, Xanthoria parietina, Vulpicida pinastri and Hypogymnia physodes. The results showed that the concentration of phenolic compounds is higher in sorediate than in non-sorediate lobe ends of V. pinastri and H. physodes as well as in apothecia of X. parietina compared to other parts of the thallus. These results were in accordance with ODT predicting higher allocation of phenols in structures that are most important for the fitness of an individual genet or ramet. This pattern was parallel in all species regardless whether the compounds originate from either acetate-mevalonate or shikimic acid pathways. Moreover, both sexual (X. parietina apothecia) and asexual (soralia of V. pinastri and H. physodes) reproductive structures were higher in phenols compared to somatic tissue.