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Harsh habitats dominated by invasive species are difficult to restore. Invasive grasses in arid environments slow succession toward more desired composition, yet grass removal exacerbates high light and temperature, making the use of "nurse plants" an appealing strategy. In this study of degraded subtropical woodlands dominated by alien grasses in Hawai'i, we evaluated whether individuals of two native (Dodonaea viscosa, Leptocophylla tameiameia) and one non-native (Morella faya) woody species (1) act as natural nodes of recruitment for native woody species and (2) can be used to enhance survivorship of outplanted native woody species. To address these questions, we quantified the presence and persistence of seedlings naturally recruiting beneath adult nurse shrubs and compared survival and growth of experimentally outplanted seedlings of seven native woody species under the nurse species compared to intact and cleared alien-grass plots. We found that the two native nurse shrubs recruit their own offspring, but do not act as establishment nodes for other species. Morella faya recruited even fewer seedlings than native shrubs. Thus, outplanting will be necessary to increase abundance and diversity of native woody species. Outplant survival was the highest under shrubs compared to away from them with few differences between nurse species. The worst habitat for native seedling survival and growth was within the unmanaged invasive grass matrix. Although the two native nurse species did not differentially affect outplant survival, D. viscosa is the most widespread and easily propagated and is thus more likely to be useful as an initial nurse species. The outplanted species showed variable responses to nurse habitats that we attribute to resource requirements resulting from their typical successional stage and nitrogen fixation capability.

Abstract Myrica faya Aiton (fire tree, faya) is an underused species with a diverse flavonoid composition (anthocyanins, flavonols, ellagitannins) which can promote positive effects on human health. M. faya has been reported to possess high antioxidant activities, but its potential in the prevention of type II diabetes has not been evaluated so far. In the present study, eight M. faya samples from different areas of Madeira and Azores archipelagos (Portugal) were collected to determine their phytochemical profile and then tested for their in vitro anti-diabetic and antioxidant activities. The analyzed extracts showed strong inhibitory activities towards α -glucosidase, aldose reductase and glycation of bovine serum albumin (BSA) and moderate effects towards α-amylase and lipase (by comparison with reference compounds). Cyanidin-3- O -glucoside and ellagitannins were the main bioactive agents involved in the anti-diabetic effects of M. faya. Such results may provide important scientific evidence for further utilization of M. faya as dietary or nutraceutical products for the prevention and/or control of hyperglycaemia-associated complications. Graphical abstract Unlabelled Image [ABSTRACT FROM AUTHOR]

Knowledge about folk medicines is limited to elder community members of remote communities, like Sete Cidades in the Azores. The Azores, 1300 km west of Portugal, are nine volcanic islands, totalling 2330 km2 of land dispersed by 173,200 km2 in the North Atlantic Ocean. The present study aims to scientifically document the uses of plant species for medicinal purposes, in the Sete Cidades. Twenty-eight community members from 40 to 84 years of age, of whom half were 55 to 64 years old, were interviewed. Twenty-nine taxa were reported as being used for medicinal purposes, ten of which have not been previously reported for ethnomedicinal use in Portugal, with a first record of the use of Morella faya. Leaves were the most used plant part (55%), and decoction the most common preparation mode. The five reported taxa with both the highest use value (0.71−0.25) and relative frequency of citation (0.14−0.11) were Clinopodium menthifolium subsp. ascendens, Aloysia citriodora, Mentha x piperita, Citrus limon and Rosmarinus officinalis. The traditional uses of some of the reported plants are supported by scientific studies, confirming their ethnomedicinal value and the need to preserve local knowledge of folk medicine practices.

It has been shown in some cases that nitrogen (N) addition to soil will increase abundance of plant invaders because many invaders have traits that promote rapid growth in response to high resource supply. Similarly, it has been suggested, and sometimes shown, that decreasing soil N via carbon (C) additions can facilitate native species recovery. Yet all species are unlikely to respond to resource supply in the same way. We asked how soil nutrients and competition affect native and exotic woody species in a restoration experiment where we added N or C, and crossed soil manipulation with the manipulation of dominant exotic grass abundance in a Hawaiian subtropical woodland. We related changes in survival and growth of outplanted individuals to native/exotic status and plant traits. As a group, N-fixers showed reduced survival compared to non-fixers in response to added N, with Morella faya (exotic) and Acacia koa (native) having dramatic negative responses. Among non-fixers, species with greater foliar %N had more positive survival responses to increasing soil N. Specific leaf area was not predictive of responses to nutrients or competition. In general, responses to carbon addition were weak, although reducing competition from existing exotic grasses was beneficial for all outplanted species, with N-fixers showing the most positive response. We conclude that commonly used restoration strategies to clear exotic species or lower soil resources with C addition will most greatly benefit N-fixing species, which themselves may be unwanted invaders. Thus statements about the influence of increased soil N on invasions should be carefully dissected by considering the traits (such as N-fixation status) of the regional species pool. [ABSTRACT FROM AUTHOR]

The unique ecosystems of the Hawaiian Islands are progressively being threatened following the introduction of exotic species. Operational implementation of remote sensing for the detection, mapping and monitoring of these biological invasions is currently hampered by a lack of knowledge on the spectral separability between native and invasive species. We used spaceborne imaging spectroscopy to analyze the seasonal dynamics of the canopy hyperspectral reflectance properties of four tree species: (i) Metrosideros polymorpha, a keystone native Hawaiian species; (ii) Acacia koa, a native Hawaiian nitrogen fixer; (iii) the highly invasive Psidium cattleianum; and (iv) Morella faya, a highly invasive nitrogen fixer. The species specific separability of the reflectance and derivative-reflectance signatures extracted from an Earth Observing-1 Hyperion time series, composed of 22 cloud-free images spanning a period of four years and was quantitatively evaluated using the Separability Index (SI). The analysis revealed that the Hawaiian native trees were universally unique from the invasive trees in their near-infrared-1 (700–1,250 nm) reflectance (0.4 > SI > 1.4). Due to its higher leaf area index, invasive trees generally had a higher near-infrared reflectance. To a lesser extent, it could also be demonstrated that nitrogen-fixing trees were spectrally unique from non-fixing trees. The higher leaf nitrogen content of nitrogen-fixing trees was expressed through slightly increased separabilities in visible and shortwave-infrared reflectance wavebands (SI = 0.4). We also found phenology to be key to spectral separability analysis. As such, it was shown that the spectral separability in the near-infrared-1 reflectance between the native and invasive species groups was more expressed in summer (SI > 0.7) than in winter (SI < 0.7). The lowest separability was observed for March-July (SI < 0.3). This could be explained by the invasives taking advantage of the warmer summer period to expand their canopy. There was, however, no specific time window or a single spectral region that always defined the separability of all species groups, and thus intensive monitoring of plant phenology as well as the use of the full-range (400–2,500 nm) spectrum was highly advantageous in differentiating each species. These results set a basis for an operational invasive species monitoring program in Hawai’i using spaceborne imaging spectroscopy.

The decomposition of leaf litter of terrestrial origin is a fundamental process in aquatic ecosystems in forest contexts. Little is known about what drives leaf litter decomposition in oceanic islands. We examined the relative importance of leaf litter identity ( Acacia melanoxylon, Pittosporum undulatum, Morella faya) and environmental conditions on litter decomposition in seven lakes in the oceanic archipelago of Azores for 28 and 56 days. Leaf litter was incubated in coarse and fine mesh bags for the assessment of the relative contribution of macroinvertebrates to leaf litter decomposition. Leaf litter mass loss generally did not differ between mesh sizes, suggesting that in these lakes macroinvertebrates generally have a negligible role on leaf decomposition. Leaf litter decomposition was in the order M. faya < A. melanoxylon < P. undulatum. A negative correlation was found between leaf litter mass loss and lignin concentration. Mass loss of P. undulatum was related to lake elevation and chlorophyll a (taken as surrogates for water temperature and dissolved nutrient availability, respectively), whereas mass loss of M. faya was related to chlorophyll a on day 56. These results suggest that changes in the composition of the leaf litter input and environmental conditions can affect leaf litter decomposition in Azorean lakes, with potential consequences for nutrient cycling. [ABSTRACT FROM AUTHOR]

Numerous rhizoliths were observed in aeolian Pleistocene sediments (ca. 80 ka) on the Ponta da São Lourenço Peninsula on eastern Madeira. Surface of some rhizoliths locally exhibit bulbous swellings which were identified as rhizobial root nodules. Based on palaeoenvironmental analysis and a comparison with other rhizoliths in the Macaronesian region, the arborescent species of Morella faya , domestic to the Madeira Island, is suggested as the source taxon for the rhizoliths. Actinorhizal fungi of the genus Frankia are considered to be responsible for creating the nodules. Tree rhizoliths also document the changes in climate and plant cover composition on Madeira. Their origin dates to a rather humid period dominated by partly continuous arborescent vegetation. • The rare occurrence of fossil rhizobial nodules on flowering plants. • A new perspective on taxonomic identification of rhizoliths using the mycorrhizal symbiosis. • Confirmation of the role of Morella faya as a probable coloniser of fossil sand dunes and nitrogen donor. [ABSTRACT FROM AUTHOR]

Aim: To study the differences in the edaphic properties between stemflow infiltration areas around different tree species and between these and other areas of the forest. Methods: Soil samples were collected in stemflow infiltration areas and other areas only exposed to throughfall. pH, soluble salt concentration, soil organic carbon and nitrogen, exchangeable bases and Al, soluble and available phosphorus and phosphate retention were measured in the soil samples. The inputs of water and H, Na, K, Ca, Mg, TOC, Fe, NO, SO, PO, and Cl that reached these areas were calculated. Results: Comparison of the soil properties measured in the throughfall and stemflow infiltration areas corresponding to each species revealed significant differences ( p < 0.05), except for exchangeable Mg and Al. Differences were observed between i) the stemflow infiltration areas around Morella faya and around each of the other species, and ii) the throughfall infiltration area and the stemflow infiltration area around each of the different species. pH, electric conductivity and available phosphorus of sampled soils were correlated with the corresponding stemflow inputs. Conclusions: The edaphic properties varied in different below-canopy infiltration areas (mainly between the stemflow infiltration area around M. faya and other parts of the forest soil). [ABSTRACT FROM AUTHOR]

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The use of imaging spectroscopy for florisic mapping of forests is complicated by the spectral similarity among co-existing species. Here we evaluated an alternative spectral unmixing strategy combining a time series of EO-1 Hyperion images and an automated feature selection in Multiple Endmember Spectral Mixture Analysis (MESMA). The temporal analysis provided a way to incorporate species phenology while feature selection indicated the best phenological time and best spectral feature set to optimize the separability between tree species. Instead of using the same set of spectral bands throughout the image which is the standard approach in MESMA, our modified Wavelength Adaptive Spectral Mixture Analysis (WASMA) approach allowed the spectral subsets to vary on a per pixel basis. As such we were able to optimize the spectral separability between the tree species present in each pixel. The potential of the new approach for floristic mapping of tree species in Hawaiian rainforests was quantitatively assessed using both simulated and actual hyperspectral image time-series. With a Cohen's Kappa coefficient of 0.65, WASMA provided a more accurate tree species map compared to conventional MESMA (Kappa = 0.54; p -value < 0.05. The flexible or adaptive use of band sets in WASMA provides an interesting avenue to address spectral similarities in complex vegetation canopies. [ABSTRACT FROM AUTHOR]

Abstract: We evaluated the potential of a multi-temporal Multiple Endmember Spectral Mixture Analysis (MESMA) for invasive species mapping in Hawaiian rainforests. Earth Observing-1 Hyperion time series data were compiled in a single image cube and ingested into MESMA. While the temporal analysis provided a way to incorporate species phenology, a feature selection technique automatically identified the best time and best spectral feature set to optimize the separability among the native and invasive tree species in our study area. We initiated an alternative Separability Index (SI)-based feature selection approach in which a boundary condition reduced the amount of correlation in the selected spectral subset. We hypothesized that redundant spectral information could be avoided, and improved plant detection accuracy could be achieved, with reduced computational time due to the selection of fewer bands in the mixture analysis. Our analysis showed a systematic increase in the invasive species detection success when we compared the output of multi-temporal MESMA (Kappa=0.78) with that of the traditional unitemporal approach (Kappa=0.51–0.69). Even for unitemporal MESMA, in which only a single input image was used, the band selection strategy was beneficial both in plant detection accuracy and computational time. We could further demonstrate that, despite a lack of imagery covering all phenological events, a proper band selection strategy can emphasize subtle spectral and phenological differences between species and can thereby partly compensate for this lack of data. This creates opportunities for mapping in areas where cloud cover is a limiting factor for building extended spectral image time series. This approach is sufficiently general and inherently adaptive, thereby supporting species mapping using Hyperion and forthcoming space-borne imaging spectrometers. [Copyright &y& Elsevier]

We evaluated the potential of multi-temporal Multiple Endmember Spectral Mixture Analysis (MESMA) of Earth Observing-1 Hyperion data for detection of invasive tree species in the montane rainforest area of the Hawaii Volcanoes National Park, Island of Hawaii. We observed a clear seasonal trend in invasive species detection success when unmixing results were cross-referenced to ground observations; with Kappa coefficients (indicating detection success, 0–1) ranging between 0.66 (summer) and 0.69 (winter) and 0.51–0.53 during seasonal transition periods. An increase of Kappa to 0.80 was observed when spectral features extracted from September, August and January were integrated into MESMA. Multi-temporal unmixing improved the detection success of invasive species because spectral information acquired over different portions of the growing season allowed us to capture species-specific phenology, thereby reducing spectral similarity among species. [ABSTRACT FROM PUBLISHER]

Summary: Laurel forests in the Canary Islands (Spain) survive where humid conditions are guaranteed throughout the year. On peaks and ridges, laurel forest gives way to mixed evergreen tree-heath/beech forest of low stature (“fayal–brezal”) that has to cope with rapidly changing light, temperature and humidity conditions due to the occurrence of intermittent sunny and foggy periods during the mostly rainless summer. These conditions are poorly understood and there is a lack of information on the interrelations between tree physiological behavior and ambient climatic and soil water conditions in fayal–brezal. In this study sap velocities were measured for 2years in two dominant tree species (Myrica faya and Erica arborea) in a ridge-top forest in the National Park of Garajonay on the island of La Gomera. The resulted average daily stand transpiration was 1.2±0.12mm (416mmyear−1). However, the narrow-leaved E. arborea exhibited higher sap velocities than the broad-leaved M. faya. Also, sap velocity increased with stem diameter in E. arborea but not in M. faya. Nocturnal flow activity was observed throughout the year and reflected ambient conditions on some occasions, and stem water storage recovery on others. Strong stomatal control in response to increases in vapor pressure deficit was seen in both species. Fog reduced sap velocity from 10% up to 90% but no consistent pattern was found. Soil water uptake during the dry summer (246mm) was much larger than atmospheric water inputs (41mm, rain and fog). The low moisture levels in the top 0.3m of the soil had limited influence on transpiration rates indicating that vegetation must have had access to moisture in deeper layers. [Copyright &y& Elsevier]

The unique ecosystems of the Hawaiian Islands are progressively being threatened following the introduction of exotic species. Operational implementation of remote sensing for the detection, mapping and monitoring of these biological invasions is currently hampered by a lack of knowledge on the spectral separability between native and invasive species. We used spaceborne imaging spectroscopy to analyze the seasonal dynamics of the canopy hyperspectral reflectance properties of four tree species: (i) Metrosideros polymorpha, a keystone native Hawaiian species; (ii) Acacia koa, a native Hawaiian nitrogen fixer; (iii) the highly invasive Psidium cattleianum; and (iv) Morella faya, a highly invasive nitrogen fixer. The species specific separability of the reflectance and derivative-reflectance signatures extracted from an Earth Observing-1 Hyperion time series, composed of 22 cloud-free images spanning a period of four years and was quantitatively evaluated using the Separability Index (SI). The analysis revealed that the Hawaiian native trees were universally unique from the invasive trees in their near-infrared-1 (700-1,250 nm) reflectance (0.4 > SI > 1.4). Due to its higher leaf area index, invasive trees generally had a higher near-infrared reflectance. To a lesser extent, it could also be demonstrated that nitrogen-fixing trees were spectrally unique from non-fixing trees. The higher leaf nitrogen content of nitrogen-fixing trees was expressed through slightly increased separabilities in visible and shortwave-infrared reflectance wavebands (SI = 0.4). We also found phenology to be key to spectral separability analysis. As such, it was shown that the spectral separability in the near-infrared-1 reflectance between the native and invasive species groups was more expressed in summer (SI > 0.7) than in winter (SI < 0.7). The lowest separability was observed for March-July (SI < 0.3). This could be explained by the invasives taking advantage of the warmer summer period to expand their canopy. There was, however, no specific time window or a single spectral region that always defined the separability of all species groups, and thus intensive monitoring of plant phenology as well as the use of the full-range (400-2,500 nm) spectrum was highly advantageous in differentiating each species. These results set a basis for an operational invasive species monitoring program in Hawai'i using spaceborne imaging spectroscopy. [ABSTRACT FROM AUTHOR]

Logistic regression models used to predict tree mortality are critical to post-fire management, planning prescribed burns and understanding disturbance ecology. We review literature concerning post-fire mortality prediction using logistic regression models for coniferous tree species in the western USA. We include synthesis and review of: methods to develop, evaluate and interpret logistic regression models; explanatory variables in logistic regression models; factors influencing scope of inference and model limitations; model validation; and management applications. Logistic regression is currently the most widely used and available technique for predicting post-fire tree mortality. Over 100 logistic regression models have been developed to predict post-fire tree mortality for 19 coniferous species following wild and prescribed fires. The most widely used explanatory variables in post-fire tree mortality logistic regression models have been measurements of crown (e.g. crown scorch) and stem (e.g. bole char) injury. Prediction of post-fire tree mortality improves when crown and stem variables are used collectively. Logistic regression models that predict post-fire tree mortality are the basis of simple field tools and contribute to larger fire-effects models. Future post-fire tree mortality prediction models should include consistent definition of model variables, model validation and direct incorporation of physiological responses that link to process modelling efforts. [ABSTRACT FROM AUTHOR]

The article presents a study which examines the long-term effect of grass invasions and subsequent fire in dry submontane habitats in Hawaii in 2011. It revealed that sites that had changed to exotic grassland after a 1970 fire stayed prevailed by exotic grasses with no increase in native cover in spite 37 years of fire suppression. It showed that native species reveal little recovery in burned woodlands in Hawaii in spite decades of fire suppression.

Abstract: Canopy conductance (g c) in a ridge-top cloud forest in the Garajonay National Park on La Gomera (Canary Islands) was derived by using the Jarvis–Stewart multiplicative algorithm and validated by inverting the Penman–Monteith equation using measured sap-flow data for the two main species, Myrica faya (beech) and Erica arborea (tree-heath). Canopy conductance correlated well with global radiation and vapour pressure deficit, and the multiplicative algorithm reproduced the daytime and seasonal course of g c satisfactorily using only these two factors under moderate and high evaporative conditions. There was no significant relation between soil moisture content in the first 0.3m and g c, even though topsoil moisture reached very low values in summer, suggesting the roots had access to water at deeper levels. [Copyright &y& Elsevier]

The article determines how a plant species invasion affects avian abundance and composition across a range of submontane ecosystems in Hawaii. In doing so, the researchers use airborne imaging spectroscopy and scanning light detection and ranging (LiDAR), along with bioacoustic recordings. Results showed that total avian abundance and the ratio of native to exotic avifuana were highest in habitat with the highest canopy cover and height. Comparing biophysically equivalent sites, stands dominated by native Metrosideros polymorpha trees hosted larger native avian communities than did mixed stands of Metrosideros and the invasive tree Morella faya. Other significant analyses relative to the matter are provided.

We explored whether the invasion of an exotic, nitrogen (N) fixing tree into native Hawaiian tropical forests has altered regional emissions of nitrous oxide (N2O) and nitric oxide (NO), two atmospherically important trace gases produced by microorganisms in soils. Ecosystem processes, including nitrification and N-oxide emissions, were not affected by Morella faya (formerly Myrica faya) invasion until it dominated the community with few native species in the overstory or understory. Remote-sensing estimates of upper-canopy leaf N concentration were strongly correlated to N-oxide emissions in ecosystems at the mesic-wet end of a precipitation gradient, where temperatures are warm, relatively constant, and N limits biological processes. In contrast, remotely sensed and field-based canopy chemistry was not related to N-oxide emissions in dry forest ecosystems where the seasonality of temperature and moisture exerted stronger control over soil gas fluxes. Thus, remote sensing of canopy N was useful for estimating the impact of M. faya on regional N-oxide emissions only in regions receiving >1800 mm rainfall annually. Our estimates of N-oxide emissions from M. faya are half as large and 35 times more precise than those made using traditional, plot-level methods of extrapolation. Over the 40 years since its first occurrence in wet forests of Hawai'i Volcanoes National Park, M. faya has increased N-oxide emissions 16-fold, with its effects most pronounced in summer and at the N-rich centers of dense, monospecific stands. [ABSTRACT FROM AUTHOR]

We compiled a time series of Earth Observing-1 Hyperion satellite observations with field measurements to compare the structural, biochemical, and physiological characteristics of an invasive nitrogen-fixing tree Myrica faya and native Metrosideros polymorpha in montane rainforests in Hawai’i. Satellite-based canopy water measurements closely tracked variations in leaf area index, and the remotely sensed photochemical and carotenoid reflectance indices (PRI, CRI) indicated variations in upper-canopy leaf chlorophyll and carotenoid content during a climatological transition. The PRI and CRI were related to differences in light-use efficiency of each species, as indicated by field measurements of leaf electron transport rate. The suite of hyperspectral metrics indicated maximum differences in the structure, biochemistry, and physiology of Myrica and Metrosideros when canopy vapor pressure deficit was high during hotter and drier periods. These satellite data, combined with the Carnegue-Ames-Stanford Approach (CASA) carbon cycle model, suggested that Myrica growth rates were 16–44% higher than Metrosideros, with relative differences between species closely linked to climate conditions. The satellite hyperspectral data identified the basic biological mechanisms favoring the spread of an introduced tree, and provided a more detailed understanding of how vegetation–climate interactions affect the time course of plant growth with respect to the invasion process. [ABSTRACT FROM AUTHOR]

In the Western Canary Islands, Myrica faya and Myrica rivas-martinezii (Myricaceae) are phylogenetically close, endemic, actinorhizal species presumed to be remnants either of the European or the African Tertiary floras. Unisolated Frankia strains from field-collected nodules on Tenerife, Gomera, and La Palma Islands were compared by their rrs gene and 16S–23S intergenic spacer (IGS) restriction patterns. To compare the genetic diversity of Frankia strains from within and outside the host’s native range, nodules of M. faya field plants were collected both in Canary Islands and in Hawaii, where this species is an exotic invasive. Myrica rivas-martinezii, endemic to the Canary Islands, was sparsely nodulated in the field. Frankia strains harbored in field-collected nodules of M. faya and M. rivas-martinezii belonged to the Elaeagnaceae strains’ genetic cluster and exhibited a high degree of diversity. Frankia genotypes were specific to each host species. In the Canary archipelago, we found no relationship between site of collection and Frankia genotype for M. faya. The only exceptions were strains from site 2 in Tenerife, a location with a geological history different from the other sites sampled. Hawaiian and Canarian M. faya strains had no genotypes in common, raising questions concerning the origin of M. faya-infective Frankia in Hawaii. Nodular strains of M. rivas-martinezii from nursery plants were genetically characterized and shown to be divergent from the strains of field-collected nodules and belong to the Alnus-Casuarina strains cluster. This suggests Myrica may have the potential to nodulate with a broader range of Frankia genotypes under artificial conditions than has been detected in field-collected nodules. [ABSTRACT FROM AUTHOR]

Myrica faya, native to the azores, Madeira, and the Canary Islands, was introduced to Hawaii where it has become a noxious wee. Exploration of the native habitats for potential biocontrol agents yielded several new or noteworthy disease records: cankers caused by Nectria galligena and Cryphonectria sp., dieback caused by ramularia destructive and Botryosphaeria ribis, and root rot caused by Armillaria mellea. [ABSTRACT FROM AUTHOR]

Knowledge about folk medicines is limited to elder community members of remote communities, like Sete Cidades in the Azores. The Azores, 1300 km west of Portugal, are nine volcanic islands, totalling 2330 km2 of land dispersed by 173,200 km2 in the North Atlantic Ocean. The present study aims to scientifically document the uses of plant species for medicinal purposes, in the Sete Cidades. Twenty-eight community members from 40 to 84 years of age, of whom half were 55 to 64 years old, were interviewed. Twenty-nine taxa were reported as being used for medicinal purposes, ten of which have not been previously reported for ethnomedicinal use in Portugal, with a first record of the use of Morella faya. Leaves were the most used plant part (55%), and decoction the most common preparation mode. The five reported taxa with both the highest use value (0.71–0.25) and relative frequency of citation (0.14–0.11) were Clinopodium menthifolium subsp. ascendens, Aloysia citriodora, Mentha x piperita, Citrus limon and Rosmarinus officinalis. The traditional uses of some of the reported plants are supported by scientific studies, confirming their ethnomedicinal value and the need to preserve local knowledge of folk medicine practices. [ABSTRACT FROM AUTHOR]

The author focuses on a study by researcher S.G. Yelenik and coworkers published in the journal in 2013 regarding invasion of the exotic grass Melinis minutiflora into Metrosideros polymorpha woodlands in Hawaii. According to the research, the invasion of the grass led to faster nitrogen cycling but leaking of nitrogen from invaded grasslands led to the invasion of the exotic species Morella faya. He mentions that negative feedback cycle in the nature can reduce exotic-grass invasion.

Experiments were performed to determine the role of the leafhopper Sophonia rufofascia (Kuoh & Kuoh) in damage observed on forest and watershed plants in the Hawaiian Islands. Laboratory manipulation of leafhopper populations on fiddlewood, Citharexylum spinosum L., caused interveinal chlorosis and vein browning on young fully expanded leavessimilar to that observed on leafhopper infested plants seen in the field and necrosis on older leaves. Field studies with caged 'uluhe' fern, Dicranopteris linearis (Burman), demonstrated that frond veins turned brown within 2 d of leafhopper feeding; and by 141 d after feeding, an average of 85% of the surface area of the fronds were necrotic compared with only 12% necrosis in untreated cages. Field trials with stump-cut firetree, Myrica faya Aiton, were performed to determinethe effect of leafhopper feeding on new growth. Our studies showed that the new growth in exclusion cages had significantly greater stem length and diameter, a higher number of nodes, fewer damaged leaves, and almost twice as much leaf area compared with plants caged but with the sides left open to permit leafhopper access. Microscopic examination of sections through damaged areas of several leafhopper host plants showed vascular bundle abnormalities similar to those associatedwith hopperburn caused by potato leafhopper, Empoasca fabae (Harris), feeding on alfalfa. On Hawaiian tree fern, Cibotium splendens (Gaudichaud), oviposition into the midvein also disrupted vascular bundle integrity and often caused death of the distal portions of the pinnule. [ABSTRACT FROM AUTHOR]