Wet Habitats Research Articles

First record of Pluchea dioscoridis (Asteraceae) in Northern Libya

Pluchea dioscoridis (L.) DC. is a species native to Eastern Africa that has been recorded for the first time in northern Libya. It was discovered growing around the city of Benghazi in populations of more than 100 plants beside roads and inside city gardens, and also on the edge of the salt marshes in a typical wet habitat of halophyte plants about five kilometres east of Benghazi and not far from the shoreline in north-east Libya. Populations of this plant were first noticed in 2018 once the civil war was over in Benghazi and confirmed during an investigative research project that aimed to evaluate the state of vegetation four years after the evacuation of the city.

Seed dispersal by waterbirds: a mechanistic understanding by simulating avian digestion

Waterbirds disperse plant species via ingestion and egestion of seeds (endozoochory). However, our understanding about the regulating effects of seed traits, underlying mechanisms and possible (co)evolutionary processes is limited by our traditional reliance on data from feeding experiments with living waterbirds. Here, we overcome these limitations by developing and applying a new bioassay that realistically simulates digestive processes for Anseriformes waterbirds. We test three hypotheses: 1) seed survival and germination are most affected by mechanical digestion in the waterbird gizzard; 2) seed size, hardness, imbibition and shape regulate seed survival; and 3) plants growing in aquatic habitats benefit most from endozoochory by waterbirds. Experiments with 28 200 seeds of 48 plant species demonstrated species‐specific seed survival that was entirely determined by digestion in the avian gizzard. Intestinal digestion did not affect seed survival but affected seed establishment (germinability and germination time) for 21% of the species. Large, hard seeds survived the simulations the best, in contrast to generally higher seed survival for smaller seeds during in vivo experiments. This mechanistically explains that small seeds escape digestive processes rather than being inherently more resistant (the ‘escape mechanism'), while large seeds are retained until fully digested or regurgitated (the ‘resistance and regurgitation mechanism'). Plants growing in wetter habitats had similar seed survival, but digestive processes stimulated their germinability and accelerated their germination more than for terrestrial plants. This indicates a relative advantage of endozoochory for plant species growing in wet habitats, possibly reflecting a co‐evolutionary response related to dormancy breaking by gut passage. Simulating seed gut passage using a bioassay allowed establishing mechanisms and identifying relevant seed traits involved in seed dispersal by waterbirds. This information enhances our understanding of how animal species shape plant species distributions, which is extremely relevant now that current anthropogenic pressures already severely impact plant dispersal capacities.

Response of rove-beetle (Staphylinidae) assemblages to the cumulative effect of wildfire and linear footprint in boreal treed peatlands.

Cumulative effects of anthropogenic and natural disturbances have become increasingly relevant in the context of biodiversity conservation. Oil and gas (OG) exploration and extraction activities have created thousands of kilometers of linear footprints in boreal ecosystems of Alberta, Canada. Among these disturbances, seismic lines (narrow corridors cut through the forest) are one of the most common footprints and have become a significant landscape feature influencing the maintenance of forest interior habitats and biodiversity. Wildfire is a common stand-replacing natural disturbance in the boreal forest, and as such, it is hypothesized that its effects can mitigate the linear footprint associated with OG exploration, but only a few studies have examined its effectiveness. We studied the short-term (1year post-fire) response of rove-beetle assemblages to the combined effects of wildfire and linear footprint in forest, edge, and seismic line habitats at burned and unburned peatlands along the southwest perimeter of the 2016 Horse River wildfire (Fort McMurray). While rove-beetle species richness was higher in seismic lines in both the burned and unburned habitats compared with the adjacent peatland, diversity was greater only in seismic lines of burned areas. Abundance was lower in the burned adjacent peatland but similarly higher in the remaining habitats. Assemblage composition on seismic lines was significantly different from that in the adjacent forest and edge habitats within both burned and unburned sites. Moreover, species composition in burned seismic lines was different from either unburned lines or burned forest and edge. Euaesthethus laeviusculus and Gabrius picipennis were indicator species of burned line habitats, are sensitive to post-fire landscapes and can occupy wet habitats with moss cover more efficiently than when these habitats are surrounded by unburned forest. Although these results are based on short-term responses, they suggest that wildfire did not reduce the linear footprint, and instead, the cumulative effect of these two disturbances had a more complex influence on rove-beetle recovery at the landscape level than for other invertebrates. Therefore, continued monitoring of these sites can become useful to evaluate changes over time and to better understand longer-term biodiversity responses to the cumulative effects of wildfire and linear disturbances in boreal treed peatlands, given the long-lasting effect of such disturbances.

Evolution of the common pochard (Aythya ferina, Linnaeus, 1758) population in the aquatic ecosystems of the Dniester-Prut interfluve over the last 60 years

The ecological and behavioral peculiarities of the common pochard, a diving species, with specific preferences for the aquatic habitat, are described in the article. It was noticed that only fish ponds, provided with combined food for fish, create optimal conditions for the reproduction and development of the offspring of the species. In fish habitats, where the ducks are provided with food and the energy effort is directed to reproduction, some clutches number up to 11-12 eggs and the offspring constitute an average of 7 ducklings per female. At the age of 4-5 weeks, an average of 5.3 ducklings per female survive, compared to 4.2 ducklings per female in the Prut wet habitats. The presence of food somehow reduces the competition between individuals and allows the colonization of small and shallow waters.

The lower storeys of main tree species in deciduous pioneer tree stands of fertile sites: case of Lithuania

Forest ecosystems face challenges of climate change and the pressure of economic activity on biodiversity. As European policies turn into Green Deal, ecological forestry systems, which aim to increase or at least not reduce biodiversity while maintaining high forest productivity, are becoming particularly relevant. This study examines distribution regularities of the lower storeys of main tree species in fertile not wet habitats of forest communities composed of pioneer deciduous tree species, the understanding of which will allow the development of forestry systems that exploit the natural forest regeneration potential. We used stand-wise forest inventory data on Betula spp., Populus tremula, Alnus incana mature and overmatured stands. We analysed how lower storeys are distributed in the stands of different tree species according to soil conditions, the age, stocking level and mixture. We found that most of stands are not in the second story and understory, from which new stands can be formed. Betula forests have the greatest potential for regeneration, and Alnus incana forests have the lowest one. The most important species of the second story and understory is Picea abies, rarer Fraxinus excelsior and Tilia cordata, other species are more random. With an increasing forest mixture, the second story and understory are found more often. To reduce clear-cutting in the fertile forests of pioneer tree species in forestry, we need to focus on measures to allow the development of lower storeys of the major climax tree species. Keywords: ecological forestry, forest succession, fertile site type, pioneer tree stands, temperate hemiboreal forests.

Habitat selection of black grouse in an isolated population in northern Germany-the importance of mixing dry and wet habitats.

Wildlife habitats in general must provide foraging, hiding and resting places as well as sites for reproduction. Little is known about habitat selection of black grouse in the lowlands of Central Europe. We investigated habitat selection of seven radio tagged birds in an open heath and grassland area surrounded by dense pine forests in the northern German Lüneburg Heath Nature Reserve. This site carries one of the last remaining populations in the Central European lowlands. Using resource selection functions based on presence/background data, we estimated the probability of black grouse occurrence by availability of, or distance to habitat types as well as vegetation diversity indices. Black grouse preferred undisturbed and heterogeneous habitats far from dense forests with wide sand heaths, natural grasslands and intermixed bogs, diverse vegetation and food sources, low density of (loose) shrub formations and solitary trees. Wetlands were extremely important in a landscape that is dominated by dry heaths and grasslands. About 4% (9 km2) of the nature reserve was a suitable habitat for black grouse, mostly due to lack of open areas due to the amount of dense forest, and because smaller, open heaths are only partly suitable. We suggest that to improve habitat quality and quantity for the grouse, habitat patch size and connectivity must be increased, along with a mosaic of heterogeneous landscape structures in these habitat islands. Our results may be used to inform and improve black grouse habitat management in the region and elsewhere.

Functional traits of riparian trees in the lower Fitzroy River, Western Australia

AbstractRiparian trees are critically important for maintaining the ecological function of freshwater ecosystems. Globally, anthropogenic changes to water regimes are impacting the health and distribution of riparian trees. Understanding the physiological constraints on the distribution of riparian tree species in relation to the water regime is essential for informed water resource management that seeks to limit impacts on riparian trees. To fill an identified knowledge gap for the Fitzroy River, a significant river in the wet–dry tropics of north‐western Australia, we used a trait‐based approach to characterise nine common riparian tree species in relation to their distribution along a hydrological gradient. We assessed key functional traits related to drought and flood flows. Leaf mass per unit area (LMA), leaf dry matter content (LDMC), foliar carbon content (% C) and the ratio of carbon to nitrogen (C:N) are broadly related to plant productivity and durability and may reflect resistance to fluvial stress. Traits related to water availability were stem specific density (SSD), mean xylem vessel diameter and xylem vessel density, as well as foliar δ13C which is related to water use efficiency, and leaf osmotic potential at full hydration (π100) as a measure of drought tolerance. We found that π100, δ13C and SSD values reflected species hydrological habitat preferences, with higher δ13C values and lower π100 for species distributed in the drier floodplain habitats, compared with species constrained to the riverbank. Low SSD values for species close to the riverbank may be indicative of aerenchyma tissue in response to flooding. Differences in leaf trait values were primarily attributed to differences between evergreen Myrtaceous and deciduous non‐Myrtaceous species, rather than hydrological habitat preferences. LMA was greatest for the Myrtaceous study species, with deciduous non‐Myrtaceous species associated with wetter habitats having the lowest values. The physiology of riparian trees in northern Australia is not well described for the majority of species. Our study provides insight into plant functional strategies in response to both flooding and drought and is a critical step in understanding plant responses to future water‐take scenarios to support evidence‐based decision making.

First records of Tumerozetidae and Nodocepheidae from Australia, with descriptions of new taxa and a re-assessment of the Polypterozetoidea (Oribatida, Brachypylina)

New species and a new genus of polypterozetoid oribatid mite are described from wet habitats in forests in south-eastern Australia: Tumerozetes roughleyi sp. nov. (Tumerozetidae), Nodocepheus luxtoni sp. nov. and Sacculella yarra gen. et sp. nov. (Nodocepheidae). The superfamily Polypterozetoidea has not been recorded previously from Australia. Tumerozetes roughleyi sp. nov. and Sacculella yarra gen. et sp. nov. were recorded from temperate Nothofagus cunninghami rainforest in central Victoria. Nodocepheus luxtoni sp. nov. was recorded from temperate rainforest in Tasmania and eastern Victoria. Tumerozetes was known previously only from New Zealand, and Nodocepheus from New Zealand, southern Africa and south-central America. The definitions of Tumerozetidae and Nodocepheidae are revised in the light of observations on the morphology of these new species, and their phylogenetic and biogeographical affinities with other members of the Polypterozetoidea are considered.

No species loss, but pronounced species turnover in grasslands in the Northern Alps over 25 years.

The abandonment of marginally productive habitats and the intensification of land use on productive sites have caused transformative changes in vegetation composition in Central Europe. In this study, after 25 years we resurveyed a total of 145 grassland relevés from the mid-1990s in a grassland-dominated valley of the Northern Alps of Upper Austria. We studied changes in richness and composition, and related these to underlying drivers. We found that the average species number in plots increased from 46 in the first survey period to 49 in the second one. Median species richness across sites significantly increased from 1995 to 2020 for Festuco-Brometea (55-61 species) and Galio-Urticetea (24-32 species), but did not show any significant change for the other classes. Further, we recorded substantial species turnover, with winners consisting mostly of species that prefer nutrient-rich sites, while losers were predominantly species of nutrient-poor sites. In particular, using Ellenberg Indicator Values for calculating community indices, we found an indication for ongoing eutrophication in vegetation types of nutrient-poor vegetation classes (Festuco-Brometea and Calluno-Ulicetea), and in wet habitats (Scheuchzerio-Caricetea fuscae). Community indices of wet habitats also showed clear signs of becoming more mesic. Thermophilization of community indices was evident across several vegetation classes. Further, alien species that were very rare in the mid-1990s became more abundant in the resurveyed plots, although the level of invasion is still low. Finally, community values for nutrients of plots that are located in a protected area that has been established in 2014 did not increase significantly, while this was the case in plots outside the protected area, indicating that the management of the protected area has positive effects in halting eutrophication. We conclude that despite overall species richness changing only moderately between both surveys, substantial changes in community composition toward more nitrophilic and thermophilic conditions occurred.

Living on the edge: Predicting invertebrate richness and rarity in disturbance‐prone aquatic–terrestrial ecosystems

Abstract Temporal fluctuations in cause the spatial extent of wet and dry habitats to vary in aquatic–terrestrial riverine ecosystems, complicating their biomonitoring. As such, biomonitoring efforts may fail to characterize the species that inhabit such habitats, hampering assessments of their biodiversity and implementation of evidence‐informed management strategies. Relationships between the dynamic characteristics of aquatic–terrestrial habitats and their communities are well known. Thus, habitat characteristics may enable estimation of faunal assemblage characteristics such as taxonomic richness, regardless of in‐channel water levels. We investigated whether indicators summarizing habitat survey data can predict two metrics representing terrestrial invertebrate assemblages (e.g. taxa richness) in two aquatic–terrestrial habitats: exposed riverine sediments and dry temporary streams. We also compared the performance of unimetric and multimetric habitat indicators in making predictions. In exposed riverine sediments, >88% of predictions were correlated with observed taxa richness and an index of conservation status. Values predicted by exposed riverine sediment samples were correlated with those observed in temporary stream channels with comparable riparian (i.e. largely agricultural) land use, but not those observed in channels with contrasting (i.e. more urban) land use. Unimetric habitat indicators performed similarly to more complex multimetric indicators, with each explaining ≤6% of the variability in taxa richness and the index of conservation status. The different spatial scales at which invertebrates respond to habitat conditions and at which indicators record habitat conditions, and a more comprehensive training dataset that incorporates a full range of habitat conditions (i.e. land use), may improve future predictions. We demonstrate that invertebrate assemblage characteristics can be predicted regardless of in‐channel water levels. Agreement between exposed riverine sediment predictions and temporary stream observations suggests that these predictions are transferable among a range of aquatic–terrestrial habitat types, and could thus be widely applied to aid conservation of riverine biodiversity in dynamic aquatic–terrestrial ecosystems.

Two new genera and six new species of Terrestrial Hydrometridae (Hemiptera: Heteroptera) from French Polynesia

The family Hydrometridae (Hemiptera: Heteroptera) has been previously recorded from French Polynesia based on three species in three genera: Chaetometra robusta (Hungerford, 1939) and Dolichocephalometra pacifica (Van Duzee, 1934) from the Marquesas Islands, and Hydrometra gagnei J. Polhemus & D. Polhemus, 1995 from Tahiti in the Society Islands. Based on recent surveys from montane cloud forest habitats, two new genera and and six new species of Hydrometridae are described from the Marquesas and Society Islands as follows: Marquesametra n. gen. from the Marquesas Islands, containing M. hivaoa n. sp. from Hiva Oa (Mt. Temetiu); and Prohydrometra n. gen. from the Society Islands, containing the previously described P. gagnei n. comb. from Tahiti (Tahiti Nui), and the five new species P. johnpolhemi n. sp. and P. englundi n. sp. from Raiatea (Trois Cascade and Mt. Toomaru respectively); P. tohiea n. sp. and P. moorea n. sp. from Moorea (both from Mt. Tohiea); and P. teatara n. sp. from Tahiti (Mts. Teatara). All of these new species are terrestrial, and with the exception of P. johnpolhemi, which inhabits rheocrenes, represent specialized inhabitants of upland wet forest habitats. This indicates that terrestrial ecologies have evolved multiple times within the Hydrometridae, and are the typical mode of life for species of this family occurring in the insular eastern Pacific.

A mesocosm experiment testing the competition between the invasive species Heteranthera reniformis Ruiz & Pav. and the endangered fern Marsilea quadrifolia L.

Biological invasion is one of the most severe threats to biodiversity, with invasive species altering ecosystem functioning and services. Once they arrive in the recipient community, invasive species are likely to spread and outcompete natives through higher competitive ability, with phylogenetically distant species expressing lower degree of competition than close related species. We present the results of a mesocosm experiment where a wet habitat was reproduced aiming at understanding the competitive ability of the threatened fern Marsilea quadrifolia L. and the invasive monocot Heteranthera reniformis Ruiz & Pav., two species that can coexist in paddy fields of S-Europe. The species were cultivated both in monoculture and in mixed cultures at different proportions. We assessed interspecific competition using relative growth rate, specific leaf area, leaf dry matter content, chlorophyll content, leaf nitrogen and phosphorus content as main indicator of plant efficiency in acquiring resources and physiological stress. Contrarily to what we expected, M. quadrifolia expressed high competitive ability in terms of plant growth versus the invasive species, with H. reniformis maintaining some of the traits typical of invasive species, i.e., higher specific leaf area, nitrogen and phosphorus content. The performance of the threatened species depended on plant mixtures, whereas H. reniformis performed best in monoculture. Although higher competitive ability of the invasive species cannot be ruled out in crop cultivation context, the mesocosm experiment demonstrated that the threatened species M. quadrifolia may have chances of survival in co-occurrence with the invasive species H. reniformis. In view of a robust conservation plan for the species, field-based experiments in the real context need to be performed to completely understand the relationship between species, also taking into account the crop species.

The activity of a subterranean small mammal alters Afroalpine vegetation patterns and is positively affected by livestock grazing

Subterranean rodents can act as ecosystem engineers by shaping the landscape due to soil perturbation and herbivory. At the same time, their burrow density is affected by environmental conditions, vegetation and anthropogenic factors. Disentangling this complex interplay between subterranean rodents and their environment remains challenging. In our study, we analysed the interplay of abiotic conditions, vegetation patterns and human land-use and the burrow density of the giant root-rat (GRR; Tachyoryctes macrocephalus), a subterranean rodent endemic to the Afroalpine ecosystem of the Bale Mountains in south-east Ethiopia. Specifically, we examined the effects of GRR on plant species richness and vegetation cover and vice-versa, and how these reciprocal effects might be modulated by temperature, habitat wetness and grazing. Our results showed that increasing GRR burrow density led to decreased vegetation cover, and that effects of GRR on vegetation cover were slightly stronger than vice-versa. Considering the reciprocal causation models, we found that increasing plant species richness led to increased GRR burrow density, while GRR burrow density decreased as vegetation cover increased. Increases in habitat wetness and livestock grazing intensity also directly led to increased GRR burrow density. Our results stress the importance of subterranean ecosystem engineers on vegetation and highlight the vulnerability of these complex interactions to human activity.

Global systematic review with meta-analysis shows that warming effects on terrestrial plant biomass allocation are influenced by precipitation and mycorrhizal association

Biomass allocation in plants is fundamental for understanding and predicting terrestrial carbon storage. Yet, our knowledge regarding warming effects on root: shoot ratio (R/S) remains limited. Here, we present a meta-analysis encompassing more than 300 studies and including angiosperms and gymnosperms as well as different biomes (cropland, desert, forest, grassland, tundra, and wetland). The meta-analysis shows that average warming of 2.50 °C (median = 2 °C) significantly increases biomass allocation to roots with a mean increase of 8.1% in R/S. Two factors associate significantly with this response to warming: mean annual precipitation and the type of mycorrhizal fungi associated with plants. Warming-induced allocation to roots is greater in drier habitats when compared to shoots (+15.1% in R/S), while lower in wetter habitats (+4.9% in R/S). This R/S pattern is more frequent in plants associated with arbuscular mycorrhizal fungi, compared to ectomycorrhizal fungi. These results show that precipitation variability and mycorrhizal association can affect terrestrial carbon dynamics by influencing biomass allocation strategies in a warmer world, suggesting that climate change could influence belowground C sequestration.

Small mammals (Insectivora, Rodentia, Lagomorpha) from the Early Pleistocene hominin-bearing site of Dmanisi (Georgia)

Small mammals (insectivores, rodents, and lagomorphs) from Dmanisi are here reviewed for the first time and used as a tool for paleoenvironmental proxies. The small mammal faunal list is composed of shrews (Beremendia fissidens, cf. Beremendia minor, Crocidura kornfeldi), hamsters (Cricetulus sp., Allocricetus bursae), gerbils (Parameriones aff. obeidiyensis), murids (Apodemus cf. atavus), arvicolids (Mimomys pliocaenicus, Mimomys aff. pusillus), and pikas (Ochotona sp.). A paleoenvironmental reconstruction based on the habitat weighting method has been applied to the rodent assemblage. According to this method, the most common elements indicate an open-dry habitat (36.5%), followed by water edge (25.7%) and rocky (21.0%) elements. Open-wet (15.5%) and woodland elements (1.3%) are rare. Therefore, the habitat occupied by the hominids of Dmanisi was characterized by the prevalence of arid conditions, from steppe or semi-desert to open Mediterranean forest, with stony or rocky substrate and bushy areas. The presence of permanent aquatic environments is also documented. From a biogeographic point of view, the small mammal community from Dmanisi is composed mainly by Western or Central Asian elements, with a poor representation of European elements (Mimomys, Apodemus). It is concluded that Dmanisi hominins most possibly had ecological requirements which were different from those of the Early Pleistocene hominins from Western Europe, which settled on wetter habitats. It could be also possible that Dmanisi hominins entered Southern Caucasus at an interglacial phase before the deposition of the Dmanisi site.

Effects of initial leaching for estimates of mass loss and microbial decomposition-Call for an increased nuance.

Decomposition is essential to carbon, nutrient, and energy cycling among and within ecosystems. Several methods have been proposed for studying litter decomposition by using a standardized and commercially available substrate. One of these methods is the Tea Bag Index (TBI) which uses tea bags (green and rooibos tea) incubated for ~90 days. The TBI is now applied all over the globe, but despite its usefulness and wide application, the TBI (as well as other methods) does not explicitly account for the differences in potential loss of litter mass due to initial leaching in habitats with large differences in moisture. We, therefore, studied the short‐term mass losses (3–4 h) due to initial leaching under field and laboratory conditions for green and rooibos tea using the TBI and contextualized our findings using existing long‐term mass loss (90 days) in the field for both aquatic and terrestrial environments. For both tea litter types, we found a fast initial leaching rate, which could be mistaken for decomposition through microbial activity. This initial leaching was higher than the hydrolyzable fraction given in the description of the TBI. We also found that leaching increased with increasing temperature and that leaching in terrestrial environments with high soil moisture (>90%) is almost as large as in aquatic environments. When comparing our findings to long‐term studies, we found that up to 30–50% of the mass loss of green tea reported as decomposition could be lost through leaching alone in high moisture environments (>90% soil moisture and submerged). Not accounting for such differences in initial leaching across habitats may lead to a systematic overestimation of the microbial decomposition in wet habitats. Future studies of microbial decomposition should adjust their methods depending on the habitat, and clearly specify the type of decomposition that the study focuses on.

Shorea macrophylla: Overview of Illipe Nut Producing Tree

Shorea macrophylla is also named as ‘Engkabang’ (Iban), ‘Kawang’ (Brunei), and ‘Tengkawang’ (Indonesia). It belongs to the Dipterocarpaceae family and is categorised under the genus Shorea, which can be found in the tropical rainforests in Southeast Asia. It prefers wet habitats, such as in periodically flooded alluvium and riverbanks. The tree size of S. macrophylla is medium or large; however, some researchers in Kalimantan claim it is a small tree. The flowering and fruiting systems of most Dipterocarps, including S. macrophylla, are irregular, but there is a massive flowering event once every few years. Its genetic structure is characterised by moderate genetic diversity within species and populations, as well as high genetic differentiation within local populations. Shorea macrophylla, also known as the Light Red Meranti, is a suitable timber supply for light construction work. It produces illipe nuts that are widely used as cocoa butter replacer fat. Wildlife eats the ripe illipe nuts, which contain a high oil content with mostly beneficial unsaturated triglycerides. The fat extracted from the nut are suitable for cosmetic application as it provides a good moisturising effect. Future investigation into the illipe nuts’ composition and other potential uses should be carried out.

Trait coordination in boreal mosses reveals a bryophyte economics spectrum

Abstract The study of plant trait spectra and their association with trade‐offs in resource use strategy has greatly advanced our understanding of vascular plant function, yet trait spectra remain poorly studied in bryophytes, particularly outside of the Sphagnum genus. Here, we measured 25 traits related to carbon, nutrient and water conservation in 60 moss canopies (each dominated by one of 15 moss species) across diverse boreal forest habitats and used bi‐variate correlations and multi‐variate analyses to assess trait coordination and trait spectra. We found substantial trait coordination along a main principal components axis driven by trade‐offs in carbon, nutrient and water conservation strategies. Along this trait spectrum, traits varied from resource‐acquisitive at one end (e.g. high maximum photosynthetic capacity, high tissue nitrogen content, low water‐holding capacity) to resource‐conservative at the other end, in line with resource economics theory. Traits related to carbon turnover (photosynthesis and respiration rates, litter decomposability) were positively related to nitrogen content and to desiccation rates, in line with global trait spectra in vascular plants. However, architectural traits of the moss shoots and of the moss canopy were generally unrelated to the main axis of trait variation and formed a secondary axis of trait variation, contrary to what is observed for vascular plants. Resource‐conservative trait spectra dominated in moss canopies from open and wet habitats (i.e. mires), indicating that high irradiance and possibly high moisture fluctuation induce a resource‐conservative trait strategy in mosses. Synthesis. Our work suggests that trait relationships that are well established for vascular plants can be extended for bryophytes as well. Bryophyte trait spectra can be powerful tools to improve our understanding of ecosystem processes in moss‐dominated ecosystems, such as boreal or arctic environments, where bryophyte communities exert strong control on nutrient and carbon cycling.

Changes in the distribution of bryophytes in a highly urbanised region in Western Europe (Flanders, Belgium): a species-traits analysis

ABSTRACT Introduction In densely populated, highly industrialised regions such as Flanders (northern Belgium), species are under significant environmental pressures arising from air pollution, land use changes, and climate change, which affect distribution patterns and species abundance. Methods We compared bryophyte distribution data for 1980–1999 and 2000–2019. Species traits data were analysed to detect general trends in changes in occupancy for different species of moss and liverwort. Key results Species occupancy increased for epiphytic species of both mosses and liverworts. Liverwort species growing on dead, decorticated wood declined, whereas the number of mosses growing on this substrate increased. Liverworts decreased in all terrestrial habitats except artificial stones and other rocky substrates. Occupancy increased for mosses growing on peat substrates and on hard natural rocks. Changes in occupancy among groups of taxa classified according to Ellenberg values showed that liverworts of wet or moist habitats declined compared with those of dry habitats. Liverworts of warmer regions increased; however, for those characteristic of cold climates, there was no significant change. Conclusions Improvements in air quality, particularly due to reduced SO2 and NOx emissions, has allowed epiphytic bryophyte species numbers to recover. Among terrestrial species, there has been a decline in the number of liverwort species especially, and particularly those adapted to wet, cold conditions. This is probably due to longer and more frequent drought periods during summer, coupled with rising ambient temperatures. Larger, more robust wetlands and forests could be created to mitigate against this decline, these habitats being very fragmented in Flanders.

Floristic diversity and vegetation of the az Zakhnuniyah Island, Arabian Gulf, Saudi Arabia

Islands are broadly recognized as hotspots of ecology, biological and geophysical diversity with unique plant species. The present study aimed to address the floristic composition in the Az Zakhnuniyah Island along the Arabian Gulf of Saudi Arabia. A total of 21 quadrats, of 100 m2 each were sampled, and both relative density and cover were determined. Classification (Agglomerative Hierarchical Clustering {AHC} and ordination [Detrended Correspondence Analysis (DCA) and Canonical Correspondence Analysis (CCA)] were applied to identify vegetation clusters and their correlation to the underlying soil factors. Fifty plant species belonging to 21 families were recorded. Amaranthaceae (22.9%), Poaceae (12.5%), Asteraceae and Zygophyllaceae (8.33% each) were the largest represented families. Therophytes and chamaephytes were the most represented life-forms, indicating saline-desert vegetation. Most of the surveyed plant species are used for medicinal purposes and grazing. AHC and DCA allowed identifying three vegetation clusters within three distinct habitats: cluster (A): Halopeplis perfoliata- Suaeda vermiculata in wet salt-marsh habitat, cluster (B): Limonium axillare- Zygophyllum mandaville in sabkha, and cluster (C): Heliotropium bacciferum- Panicum turgidum in sand dune habitat within the island. The CCA results imply strong relationships between floristic composition and salinity measures (CaCO3, electric conductivity, Mg+2, Na+, K+, Cl− and SO4) and soil texture. The current vegetation pattern in Zakhnuniyah Island reflects a salinity gradient with variations in soil texture. Knowledge of the floristic composition and its correlation to the environmental factors within islands should guide future conservation strategy and management efforts.