Fertilization influences the nutrient acquisition strategy of a nomadic vine in a lowland tropical forest understory

© 2018, Springer Nature Switzerland AG. Aims: Tropical tree and lianas in the understory are limited by soil nutrients despite growing in extremely low light. It is not known if nomadic vines are also limited by nutrients in low light conditions. Methods: We measured differences in root architecture and mycorrhizal colonization, and leaf nutrients of a nomadic vine, Philodendron fragrantissimum (Araceae), in nitrogen (N) and phosphorus (P) fertilization plots in a lowland tropical moist forest in central Panama to measure potential nutrient limitation. Results: Relative to plants in control plots, leaf P concentration was 54% higher and leaf N concentration was 10% higher for plants in the P- and N-addition treatments, respectively. The N:P of leaves suggested P-limitation in the N-addition treatment and the control but not in the P-addition treatment. Root branching was highest in the P-addition treatment, and P-addition reduced mycorrhizal colonization. Conclusions: The large effect of P fertilization suggests that, like many tropical plants, P. fragrantissimum has the potential to be P-limited. Although further study is needed, we suggest that nomadic vines be added to the growth forms that respond to nutrient addition in the forest understory and conclude that nutrient-limitation seems like the rule rather than the exception in the light-limited understory

New Proposal of Epiphytic Bromeliaceae Functional Groups to Include Nebulophytes and Shallow Tanks

The Bromeliaceae family has been used as a model to study adaptive radiation due to its terrestrial, epilithic, and epiphytic habits with wide morpho-physiological variation. Functional groups described by Pittendrigh in 1948 have been an integral part of ecophysiological studies. In the current study, we revisited the functional groups of epiphytic bromeliads using a 204 species trait database sampled throughout the Americas. Our objective was to define epiphytic functional groups within bromeliads based on unsupervised classification, including species from the dry to the wet end of the Neotropics. We performed a hierarchical cluster analysis with 16 functional traits and a discriminant analysis, to test for the separation between these groups. Herbarium records were used to map species distributions and to analyze the climate and ecosystems inhabited. The clustering supported five groups, C3 tank and CAM tank bromeliads with deep tanks, while the atmospheric group (according to Pittendrigh) was divided into nebulophytes, bromeliads with shallow tanks, and bromeliads with pseudobulbs. The two former groups showed distinct traits related to resource (water) acquisition, such as fog (nebulophytes) and dew (shallow tanks). We discuss how the functional traits relate to the ecosystems inhabited and the relevance of acknowledging the new functional groups

Ecological literacy: the educational foundation necessary for informed public decision making

In this introduction to the new Frontiers series on Ecoliteracy, Guest Editors Catherine Cardelús and GeorgeMiddendorf discuss the impetus behind the series for which innovative ecological educators were invited to discuss ways to teach ecological concepts to diverse groups in a variety of settings, with the aim of facilitating better informed decision making for environmental policy

Traditional use of botanicals in reducing post harvest loss at crop stacking stage in Ethiopia: A case of Farta district

534-541Insect pests, rodents, and microorganisms comprise the larger proportion for the causes of post-harvest loss. The use of insecticidal/pesticidal and insect repellent plants is a deep-rooted tradition and cultural heritage in Ethiopia. This study was conducted to gather information on traditional botanical-based pest control practices by farmers of Farta district, northern Ethiopia. The study identified plants traditionally used as pesticides/insecticides during stacking crops at harvest time. The survey showed farmers are using about 31 species of plants for bottom layering during stacking of their crops. These plants are used as pesticides and insecticides although their level of utilization varied. The most commonly used and effective plant species were Croton macrostachyus Del., Eucalyptus globules Labill., Calpurnia aurea (Ait.) Benth., Vernonia myriantha Hook. f. and Laggera tomentosa (Sch. Bip. ex A.Rich) Oliv. & Hiern, of which C. macrostachyus is the most effective. The insecticidal effect of these botanicals was compared to the synthetic insecticide diazinon (0.1 %). Twelve hours after application of powders of C. macrostachyus, E. globulus, C. aurea and L. tomentosa, the mean mortality rate of termites was equivalent to that caused by diazinon. Further, the insecticidal effect of different parts of C. macrostachyus was compared. Leaves were the most effective. This calls for further identification and adoption of cost-effective and environmental-friendly indigenous/traditional botanical based pest control methods. Identification of active principles from these plants is highly desirable

Human disturbance impacts the integrity of sacred church forests, Ethiopia.

Land-use change can have profound effects on forest communities, compromising seedling recruitment and growth, and long-term persistence of forests on the landscape. Continued forest conversion to agriculture causes forest fragmentation which decreases forest size, increases edge effects and forest isolation, all of which negatively impact forest health. These fragmentation effects are magnified by human use of forests, which can compromise the continued persistence of species in these forests and the ability of the forests to support the communities that depend on them. We examined the extent and influence of human disturbance (e.g. weedy taxa, native and exotic tree plantations, clearings, buildings) on the ecological status of sacred church forests in the northern highlands of South Gondar, Ethiopia and hypothesized that disturbance would have a negative effect. We found that disturbance was high across all forests (56%) and was negatively associated with tree species richness, density, and biomass and seedling richness and density. Contrary to expectation, we found that forests < 15.5 ha show no difference in disturbance level with distance from population center. Based on our findings, we recommend that local conservation strategies not only protect large forests, but also the small and highly used forests in South Gondar which are critical to the needs of local people, including preserving large trees for seed sources, removing exotic and weedy species from forests, and reducing clearings and trails within forests

A Preliminary Assessment of Ethiopian Sacred Grove Status at the Landscape and Ecosystem Scales.

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Putting vascular epiphytes on the traits map

1. Plant functional traits impact the fitness and environmental niche of plants. Major plant functional types have been characterized by their trait spectrum, and the environmental and phylogenetic imprints on traits have advanced several ecological fields. Yet, very few trait data on epiphytes, which represent almost 10% of vascular plants, are available. 2. We collated 76,561 trait observations for 2,882 species of vascular epiphytes and compared these to non-epiphytic herbs and trees to test hypotheses related to how the epiphytic habit affects traits, and if epiphytes occupy a distinct region in the global trait space. We also compared variation in traits among major groups of epiphytes, and investigated the coordination of traits in epiphytes, ground-rooted herbs and trees. 3. Epiphytes differ from ground-rooted plants mainly in traits related to water relations. Unexpectedly, we did not find lower leaf nutrient concentrations, except for nitrogen. Mean photosynthetic rates are much lower than in ground-rooted plants and lower than expected from the nitrogen concentrations. Trait syndromes clearly distinguish epiphytes from trees and from most non-epiphytic herbs. 4. Among the three largest epiphytic taxa, orchids differ from bromeliads and ferns mainly by having smaller and more numerous stomata, while ferns differ from bromeliads by having thinner leaves, higher nutrient concentrations, and lower water content and water use efficiency. 5. Trait networks differ among epiphytes, herbs and trees. While all have central nodes represented by SLA and mass-based photosynthesis, in epiphytes, traits related to plant water relations have stronger connections, and nutrients other than potassium have weaker connections to the remainder of the trait network. Whereas stem-specific density reflects mechanical support related to plant size in herbs and trees, in epiphytes it mostly reflects water storage and scales with leaf water content. 6. Synthesis. Our findings advance our understanding of epiphyte ecology, but we note that currently mainly leaf traits are available. Important gaps are root, shoot and whole plant, demographic and gas exchange traits. We suggest how future research might use available data and fill data gaps.ISSN:0022-047