Oceanic islands are cradles of endemism, contributing substantially to global biodiversity. A similarity in magmatic origin translates into high global comparability of substrates of volcanic islands ...on the oceanic crust with, however, slightly chemically or physically differentiated petrography in some places. Phonolites are examples of rare localities with intermediate chemical characteristics between felsic and mafic and with diverse textures. They contribute to habitat heterogeneity and offer specific growth conditions in a significantly different matrix of basaltic substrates. The explicit contribution of geodiversity to island biodiversity has been little studied, despite growing evidence of its importance on continents. On the island of La Palma, Canary Islands, isolated phonolitic rocks are conspicuous due to their light colour and specific shape. Although these outcrops only cover small areas, their unique form and composition increase within-island geodiversity. To investigate how this affects biodiversity on La Palma, we sampled all vascular plant species in 120 plots on four sets of paired sites in order to test if plant diversity and performance is enhanced on phonolitic rocks compared to basaltic rocks. We recorded species number and abundance as well as individual plant height and diameter as proxies for aboveground resource allocation and tested for differences in vegetation cover and species composition between the bedrock types. We found higher species richness and abundance on phonolites than neighbouring basaltic substrates, and individuals of the same species were larger (in height and diameter) on phonolites compared to neighbouring basalt. An endemic woody species with two distinct varieties even appears almost exclusively on the small surfaces of phonolitic rock. Despite extremely limited spatial extent, phonolitic rocks can play an important role in plant biodiversity on islands.
Pterocarpus santalinus L.f. (Red Sanders) is an endemic and endangered species largely confined to the southern portion of the Eastern Ghats, Andhra Pradesh, India. To understand its ecological and ...geographic distribution, we used ecological niche modelling (ENM) based on field sample-based distributional information, in relation to climatic and topographic datasets. Before modelling, hierarchical partitioning was used to optimize the choice of variables for better prediction and reliability. We used three ENM approaches, namely GARP, Maxent and BIOCLIM for predicting potential areas of occurrence. The ENM successfully reconstructed key features of the species geographic distribution, mainly in the forest tracts of Chittoor and Kadapa districts. GARP appeared to be more robust in prediction capabilities compared to BIOCLIM. The potential distributional area identified by these models falls mainly in regions not protected and experiencing high anthropogenic pressure owing to economic and medicinal use. The success of this model indicates that ENM-based approaches provide a promising tool for exploring various scenarios useful in the study of ecology, biogeography and conservation.
Non-technical summary
Resilience is a cross-disciplinary concept that is relevant for understanding the sustainability of the social and environmental conditions in which we live. Most research ...normatively focuses on building or strengthening resilience, despite growing recognition of the importance of breaking the resilience of, and thus transforming, unsustainable social-ecological systems. Undesirable resilience (cf.
lock-ins
,
social-ecological traps
), however, is not only less explored in the academic literature, but its understanding is also more fragmented across different disciplines. This disparity can inhibit collaboration among researchers exploring interdependent challenges in sustainability sciences. In this article, we propose that the term
lock-in
may contribute to a common understanding of undesirable resilience across scientific fields.
Technical summary
Resilience is an extendable concept that bridges the social and life sciences. Studies increasingly interpret resilience normatively as a desirable property of social-ecological systems, despite growing awareness of resilient properties leading to social and ecological degradation, vulnerability or barriers that hinder sustainability transformations (i.e., ‘undesirable’ resilience). This is the first study to qualify, quantify and compare the conceptualization of ‘desirable’ and ‘undesirable’ resilience across academic disciplines. Our literature analysis found that various synonyms are used to denote undesirable resilience (e.g., path dependency, social-ecological traps, institutional inertia). Compared to resilience as a desirable property, research on undesirable resilience is substantially less frequent and scattered across distinct scientific fields. Amongst synonyms for undesirable resilience, the term
lock-in
is more frequently and evenly used across academic disciplines. We propose that
lock-in
therefore has the potential to reconcile diverse interpretations of the mechanisms that constrain system transformation – explicitly and coherently addressing characteristics of reversibility and plausibility – and thus enabling integrative understanding of social-ecological system dynamics.
Social media summary
‘Lock-in’ as a bridging concept for interdisciplinary understanding of barriers to desirable sustainability transitions.
The research presented here investigated the impact of making targeted dimensions transparent to participants prior to their performance of a simulation exercise, on the level of dimension ratings ...and their correlations with typical performance predictors. Results from two studies, both employing between-subjects designs, showed that conceptually matched typical performance predictors were more positively associated with dimension ratings when targeted dimensions were not made transparent than when they were. In addition, only when targeted dimensions were not made transparent did conceptually matched typical performance predictors correlate more positively with dimension ratings than conceptually distinct typical performance predictors. Finally, those who were made aware of targeted dimensions received higher mean ratings in Study 1 but not in Study 2.
We tested relationships between students' expectations of psychosocial and career support through a peer advising program, the frequency of advisor behaviors consistent with these types of support ...(coded from transcripts), and advisee perceptions after receiving such support. Participants were 179 advisor-advisee dyads at a large southeastern university. Results demonstrated that advisees' expectations of psychosocial support were positively related to their perceptions of having received such support but not to the frequency of relevant advisor behaviors. Advisee expectations for career support did not predict advisor behavior. However, such expectations strengthened the relationship between the frequency of relevant advisor behaviors and advisees' perceptions of the career support received. These results underscore the importance of aligning advisor-advisee expectations and behaviors.
Transplantation to a warmer site and experimental passive warming are powerful tools for predicting plant responses to climate change. Both techniques are widely applied for the study of plant ...species and community response to temperature increase. We investigated differences in height increment of Fagus sylvatica seedlings between 2 different techniques: experimental warming (passive warming) and transplantation to a warmer site. Additionally, the plants were exposed to an extreme drought to further examine the influence of the different warming techniques in combination with an additional climatic driver. We found significant differences between the 2 warming techniques for height increment, which were mainly attributed to the case with additional drought exposure (significant interaction between warming and drought). Surprisingly, when subjected to drought, experimental warming had no negative effect on height increment of seedlings, while transplantation decreased height increment by 32% when subjected to drought. Growth did not show a linear dependence on the magnitude of warming. Differences between the warming techniques can therefore not be explained by differences in realized temperature increases. The results of this study emphasize the complexity of simulating global warming, as required for accurate prediction of shifts in plant performance. The role of co-varying parameters, such as evapotranspiration, photosynthetically active radiation, and wind speed, in addition to experimental temperature increases should be acknowledged when ana lyzing ecological responses to climate warming.
The influence of cyanobacterial soil crusts combined with mechanical soil disturbance on germination, establishment, growth and nutrition of
Lepidium sativum seedlings on nutrient poor sand was ...analyzed under controlled conditions in a growth chamber. Marked release of nitrate and ammonia into the soil was only found in established and older (aging) crusts. Analyses of the
15N signatures of the crust and the seedling biomass revealed, that there was clear evidence that the established seedlings took up considerable amounts of the released nitrogen. This positively affected plant performance. Mechanical disturbance of the crust led to a temporal increase of nitrogen release but later to a considerable decrease of the released nitrogen components. Undisturbed crusts had a low stimulating effect on seed germination. In contrast and independent of the presence or absence of crusts mechanical soil disturbance led to significantly higher seed germination rates. It is concluded that the occurrence of small-scale disturbance events of moderate intensity at an intermediate frequency, which is the typical disturbance regime in many natural soil crust habitats, seems to be necessary for the successful coexistence of crust organisms and higher plants in nutrient poor environments.
In einem Klimakammerexperiment wurde der Einfluß einer cyanobakteriellen Bodenkruste und gleichzeitiger mechanischer Bodenstörungen auf die Ernährung, Keimung, Etablierung, Wachstum und Ernährungszustand von
Lepidium sativum-Keimlingen untersucht. Hierbei wurde festgestellt, daß nur ältere Krusten nennenswerte Mengen an Nitrat und Ammonium in das Substrat abgeben. Die Analyse der
15N-Signaturen der
Lepidium-Pflanzen ergab klare Hinweise darauf, daß etablierte Keimlinge die von der Kruste abgegebenen Stickstoffverbindungen in erheblichem Umfang aufnehmen. Alle gemessenen Wachstumsparameter wurden hierdurch positiv beeinflußt. Mechanische Störung führte zwar zu einem kurzfristigen Anstieg der Stickstoff-Freisetzung der Kruste, langfristig jedoch zu einem deutlichen Absinken der Stickstoff-Freisetzung. Die Anwesenheit ungestörter Krusten wirkte sich nur wenig fördernd auf die Samenkeimung aus. Unabhängig von der Anwesenheit der Bodenkruste führten Bodenstörungen zu signifikant höheren Keimungsraten. Es kann daher gefolgert werden, daß für eine erfolgreiche Koexistenz von biologischen Krusten und höheren Pflanzen das Auftreten kleinräumiger Bodenstörungen mäßiger Intensität und mittlerer Frequenz, also Bedingungen, wie sie natürlicherweise an vielen Standorten biologischer Bodenkrusten auftreten, notwendig sind.
We used an online academic-advising program to examine the effects of preparatory training designed to elicit high states of learning-goal orientation and low states of avoid goal orientation. ...Results indicate that training was effective in some cases for manipulating states of goal orientation. The training did not directly affect behaviors as anticipated; however, perceptions of partner behaviors showed effects. Moreover, learning-goal orientation was related to advisee postprogram academic self-efficacy. Thus, individuals working with such mentoring programs should consider implementing goal-oriented preparatory training programs to increase mentoring relationship effectiveness. (Contains 5 tables and 2 figures.)
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