Variation and adaptation of leaf water content among species, communities, and biomes

Leaf water content (LWC) is essential for the physiological activities in plants, but its spatial variation and the underlying mechanisms in natural plant communities are unclear. In this study, we measured the LWC of 5641 plant species from 72 natural communities in China, covering most terrestrial ecosystems, to answer these questions. Our results showed that LWC, on average, was 0.690 g g–1, and was significantly higher in forests and deserts than in grasslands. LWC was significantly different among different plant life forms, and ranked on averages in the following order: herbs > shrubs > trees. Interestingly, LWC decreased with increasing humidity and increased in dry environments. Furthermore, the variations of LWC in plant communities were higher in arid areas and those species with lower LWC in a plant community were more sensitive to changing environments. These results demonstrated the adaptations of plants to water regime in their habitats. Although, phylogeny has no significant effect on LWC, plant species both in forests and grasslands evolve toward higher LWC. Variations of LWC from species to community to biome represent the cost-effective strategy of plants, where plant species in drier environment require higher input to keep higher LWC to balance water availability and heat regulation. This systematic investigation fills the gaps on how LWC varies spatially and clarifies the different adaptation mechanisms regulating LWC across scales.

Large herbivores suppress liana infestation in an African savanna

African savannas are the last stronghold of diverse large-mammal communities, and a major focus of savanna ecology is to understand how these animals affect the relative abundance of trees and grasses. However, savannas support diverse plant life-forms, and human-induced changes in large-herbivore assemblages—declining wildlife populations and their displacement by livestock—may cause unexpected shifts in plant community composition. We investigated how herbivory affects the prevalence of lianas (woody vines) and their impact on trees in an East African savanna. Although scarce (<2% of tree canopy area) and defended by toxic latex, the dominant liana, Cynanchum viminale (Apocynaceae), was eaten by 15 wild large-herbivore species and was consumed in bulk by native browsers during experimental cafeteria trials. In contrast, domesticated ungulates rarely ate lianas. When we experimentally excluded all large herbivores for periods of 8 to 17 y (simulating extirpation), liana abundance increased dramatically, with up to 75% of trees infested. Piecewise exclusion of different-sized herbivores revealed functional complementarity among size classes in suppressing lianas. Liana infestation reduced tree growth and reproduction, but herbivores quickly cleared lianas from trees after the removal of 18-y-old exclosure fences (simulating rewilding). A simple model of liana contagion showed that, without herbivores, the long-term equilibrium could be either endemic (liana–tree coexistence) or an all-liana alternative stable state. We conclude that ongoing declines of wild large-herbivore populations will disrupt the structure and functioning of many African savannas in ways that have received little attention and that may not be mitigated by replacing wildlife with livestock.

A test of rapid leaf photosynthesis-intercellular CO2 concentration response (RACiR) technique for evergreens and herbs

Using traditional photosynthesis-intercellular CO concentration (A-C) response (TACiR) curves to obtain the maximum rates of ribulose-1,5-bisphosphate carboxylase oxygenase carboxylation (V) and electron transport (J) is time-consuming and labor-intensive. Instead, the rapid A-C response (RACiR) technique provides a potential way with high efficiency. However, multiple parameter settings of RACiR technique for different plant life forms remain unclear. Here, we used Li-Cor 6800 to test the applicability and optimum parameter settings of RACiR curves for evergreens and herbs. We set 11 groups of [CO], i.e., R1 (400-1500 ppm), R2 (400-200-800 ppm), R3 (420-20-620 ppm), R4 (420-20-820 ppm), R5 (420-20-1020 ppm), R6 (420-20-1220 ppm), R7 (420-20-1520 ppm), R8 (420-20-1820 ppm), R9 (450-50-650 ppm), R10 (650-50 ppm) and R11 (650-50-650 ppm), and made contrasts between TACiR and RACiR curves. We found that V and J calculated by TACiR and RACiR overall showed no significant differences across 11 [CO] gradients (P<0.05). The efficiency and accuracy of R2, R3, R4, R9 and R10 showed higher superiority than others. Moreover, the accuracy of manual empty chamber correction method was higher than the automatic method. In conclusion, the RACiR technique could be generally used to obtain photosynthetic parameters with higher efficiency than traditional methods for various life forms.

Grass-Legume Seeding: A Sustainable Approach Towards Reclamation of Coalmine Degraded Lands in India

Most of the ecosystem services undergo significant degradation during coal mining activities with negative impacts on ecology, biodiversity and local people’s livelihoods. The cumulative effect of such large scale environmental changes is reflected in rising pollution load, earth’s temperatures and deforestation. There is no eloquence to it that coal is and will continue to be the primary fossil fuel in global energy production, there is a need to embrace sustainability as a key aspect throughout all phases of mining. The cheapest, easiest and eco-friendly approach to accelerate the trajectory of ecological restoration towards a reference state is the introduction of versatile and pioneering plant life forms like grasses and legumes. These species works on basic scientific principles based on ecological theories and incorporating them in post-mined landscapes provides multitudinous environmental benefits coupled with economic and social development. Keeping this in mind the chapter aims to emphasize the importance of grass-legume seeding during ecological restoration of mine degraded lands concerned with the concepts of sustainability.

Assessment of floral composition, structure and natural regeneration of the Tano Offin Globally Significant Biodiversity Area of Ghana

Threats of forest degradation of the Tano Offin Globally Significant Biodiversity Area present the need to generate eco-information pertinent for its conservational purposes. Ten 50 m × 50 m plots (tree layer) were assessed for plant life forms with diameter ≥ 10 cm. A 10 m × 10 m plot (shrub layer) was located within each of the 50 m × 50 m plots where plant life forms with diameter < 10 cm were assessed. 1 m × 1 m quadrats (herb layer) were laid at the corners of the 50 m × 50 m plots and its centre for canopy closure and natural regeneration assessments. Plant species (240) belonging to 59 families were identified: 171 trees, 41 lianas, 11 shrubs, 7 herbs, 7 herbaceous climbers, 1 epiphyte, 1 grass and 1 fern. Species diversity (H´) of the tree, shrub and herb layers was 2.55, 2.54 and 2.48 respectively. The average maximum tree height was 46.19 m and the basal area was 28.36 m2/ha, which is below the 35 m²/ha conventional basal area value of tropical forests. Celtis mildbraedii and Rinorea welwitschii were the most structurally significant species at the tree and shrub layers, respectively, and a total of 75 tree species were regenerating.

CURRENT STATE OF DENDROFLORA OF THE MONUMENT PARK OF GARDEN ARTISTRY OF LOCAL IMPORTANCE “PARK OF V. P. FILATOV INSTITUTE”

Problem. It is important to identify the diversity of dendroflora in the territories of nature reserves, including man-made objects. The dendroflora of Odesa parks has not been studied systematically, and some publications on the topic concern either the dendroflora of the city as a whole or the description of individual parks. Moreover, these data are partially outdated and do not reflect the current state of greenery. Aim. To conduct an inventory of tree and shrub plants of the park-monument of landscape art of local significance "Park of the V.P. Filatov Institute”, analysis of the taxonomic structure of dendroflora, diversity of plant life forms, age and quantitative composition of green plantations and detection of phytososophytic plants in the park. Methods. During the inventory of tree plantations in the park the continuous account of plantings was carried out. Identification of dendroflora species was carried out using modern reference books and determinants. Definitions of life forms (tree, bush, vine) were determined by I.G. Serebryakov. Species names of trees and shrubs were given according to floristic reports and the Determinant. The age of trees and shrubs was determined by analyzing biometric indicators. The condition of trees and their decorative features were studied. Main results. In 2020 dendroflora of the monument park of garden artistry of local importance “Park of V.P. Filatov Institute” in Odesa was inventoried. 111 species of woody plants, which belong to 77 genera, 35 families, 2 classes and 2 divisions were identified, of which: trees - 66 species (59.5%), bushes - 39 species (35.1%), lianas - 6 species (5.4%). The Pinophyta division includes 22 species from 13 genera and 5 families. In terms of the number of species Cypressaceae (12 species) and Pinaceae (8 species) are leading families, and Juniperus is a leading genus. The Magnoliophyta division includes 89 species from 64 genera and 30 families. Families Rosaceae (23 species), Salicaceae (8 species), Fabaceae (7 species), Aceraceae and Oleaceae (per 5 species each) are the leading ones in terms of the number of species. Genera maple (Acer) and poplar (Populus) are the leading ones in terms of the number of species. Decorative forms for 9 species have been identified. There are 1019 specimens of woody plants in the park, 86 specimens of trees of 15 species have trunk diameter of more than 50 cm. Among phytososophytes there is one species, which is listed in the Red Data Book of Ukraine (2009) - yew (Taxus baccata) and 31 species of plants included in the Red List of Threatened Species IUCN (2012), in total 178 specimens of plants of the studied park are a subject to special protection. Conclusions. Trees, which were planted in the first half of the twentieth century, have historical and cultural significance as living witnesses of the activities of Academician V.P. Filatov and his associates.

BIOMORPHOLOGICAL CHARACTERISTICS OF DENDROFLORA OF NNP «NYZHNIODNIPROVSKYI»

In order to preserve, reproduce and effectively use the natural complexes and objects of the DniproDelta as one of the most valuable natural floodplain-littoral complexes in Europe, which have special environmental, recreational, historical and cultural, scientific, educational and aesthetic value, and ensurethe conservationof «DniproDelta»wetland of theinternational importance,the National Natural Park «Lower Dnipro»was created(Decree of the President of Ukraine of November 24, 2015 No 657/2015).The flora of the higher vascular plants of the Park contains 820 species, 40 species of which (4.9% of the total number) are woody plants. Rosaceae Juss. (14 species), Salicaceae Mirb. (7 species), Aceraceae Juss. (3 types) are leading families of the dendroflora of the Park.Biomorphological characteristics of tree plant species in the flora of the Lower Dnipro National Nature Park were carried out according to the following classifications: 1) K. Raunkiersystem of plant life forms; 2) ecological and morphological classification of life forms of I. G. Serebryakov; 3) architectural models of F. Alle, R. Oldeman and P. Tomlinson; 4) classification of the life forms of plants of the temperate zone, which takes into account the vegetative propagation by O. V. Smirnova, L. B. Zaugolnova.AnalysisoftypesofbiomorphsaccordingtotheclassificationofK. Raunkiershowedthatthevastmajorityofdendrofloraspeciesbelongtophanerophytes, amongthem, dependingontheheightoftheplant, therearedifferentgroups-megaphanerophytes(e.g., Populustremula), mesophanerophytes(Salixalba), microphaneorphytes, nanophanerophytes(Amygdalusnana) andhamephytes(Ephedradistachia).According to the ecological and morphological classification of I. G. Serebryakov life forms, the flora of the Park is dominated by forest-steppe trees and forest-type trees.The trees which belong to one life form often differ in the principles of growth and formation of the crown, branching, and general habitus, which is generally considered as an architectural model of a particular species. According to the classification of architectural models by F. Alle, R. Oldeman and P. Tomlinson, in the flora of the Park, there are five models among which the species formed by the model of Tomlinson have a significant representation, and the species formed by the models of Manzheno and Champagne have a smaller representation.Key words:flora, tree, classification, life form, bush. З метою збереження, відтворення і ефективного використання природних комплексів та об’єктів дельти річки Дніпро як одного з найцінніших природних заплавно-літоральних комплексів у Європі, які мають особливу природоохоронну, оздоровчу, історико-культурну, наукову, освітню та естетичну цінність, забезпечення збереження водно-болотного угіддя міжнародного значення «Дельта р. Дніпро» створено Національний природний парк «Нижньодніпровський» (Указ президента України від 24 листопада 2015 року No 657/2015).Флора вищих судинних рослин Парку попередньо складає 820 видів, з них 40 видів (4,9% від загальної кількості) –деревні рослини.Провідні родини дендрофлори Парку –Rosaceae Juss. (14 видів), SalicaceaeMirb. (7 видів), AceraceaeJuss. (3 види). Біоморфологічну характеристику видів деревних рослин у флорі національного природнього парку «Нижньодніпровський» проведено за класифікаціями: 1) система життєвих форм рослин К. Раункієра; 2) еколого-морфологічна класифікація життєвих форм І. Г. Сєрєбрякова; 3) архітектурні моделі Ф. Аллє, Р. Ольдемана і П. Томлінсона; 4)класифікація життєвих форм рослин помірної зони, яка враховує вегетативне розмноження О. В. Смирнової, Л. Б. Заугольнової.Аналіз типів біоморф за класифікацією К. Раункієра показав, що переважна більшість видів дендрофлори належить до фанерофітів, серед них, в залежності від висоти рослини, виділяють різні групи –мегафанерофіти (наприклад, Populus tremula), мезофанерофіти (Salix alba), мікрофанерофіти (Amorpha fruticosa), нанофанерофіти (Amygdalus nana) та хамефіти (Ephedra distachia).За еколого-морфологічною класифікацією життєвих форм І. Г. Сєрєбрякова у флорі Парку домінують дерева лісостепового типу та дерева лісового типу.Дерева, які відносяться до однієї життєвої форми, часто відрізняютьсяпринципами наростання та формування крони, галуженням, загальним габітусом, що загалом розглядається як архітектурна модель конкретного виду. За класифікацією архітектурних моделей Ф.Аллє, Р. Ольдемана і П. Томлінсона у флорі Парку виділено п’ять моделей, серед яких, значне представництво мають види, що формуються за моделлю Томлінсона, менше представництво мають види, що формуються за моделями Манжено та Шампанії.Ключові слова: флора, дерево, класифікація, життєва форма, кущ.

Testing the potential of pollen assemblages to capture composition, diversity and ecological gradients of surrounding vegetation in two biogeographical regions of southeastern Europe

Due to the complex relationship between pollen and vegetation, it is not yet clear how pollen diagrams may be interpreted with respect to changes in floristic diversity and only a few studies have hitherto investigated this problem. We compare pollen assemblages from moss samples in two southeastern European forests with the surrounding vegetation to investigate (a) their compositional similarity, (b) the association between their diversity characteristics in both terms of richness and evenness, and (c) the correspondence of the main ecological gradients that can be revealed by them. Two biogeographical regions with different vegetation characteristics, the Pieria mountains (north central Greece) and the slopes of Ciomadul volcano (eastern Romania), were chosen as divergent examples of floristic regions, vegetation structure and landscape openness. Pollen assemblages are efficient in capturing the presence or absence, rather than the abundance in distribution of plants in the surrounding area and this bias increases along with landscape openness and vegetation diversity, which is higher in the Pieria mountains. Pollen assemblages and vegetation correlate better in terms of richness, that is, low order diversity indices. Relatively high correlation, in terms of evenness, could be potentially found in homogenous and species poor ecosystems as for Ciomadul. Composition and diversity of woody, rather than herb, vegetation is better reflected in pollen assemblages of both areas, especially for Pieria where a direct comparison of the two components was feasible, although this depends on the species-specific pollen production and dispersal, the openness of landscape and the overall diversity of vegetation. Gradients revealed by pollen assemblages are highly and significantly correlated with those existing in vegetation. Pollen assemblages may represent the vegetation well in terms of composition, diversity (mainly richness) and ecological gradients, but this potential depends on land use, vegetation structure, biogeographical factors and plant life forms.

Patterns and mechanisms underlying ecoregion delineation in North American freshwater plants

Aim: Biogeographical regionalisations are actively studied in different ecosystems, because they increase our understanding on fundamental broad-scale patterns and can help us in the establishment of conservation areas. Thus, we studied how well existing freshwater ecoregions describe geographical delineation for inland water plants and which ecogeographical gradients explain them. Location: North America, excluding Mexico and remote islands. Taxon: Freshwater vascular plants of all taxa and different functional groups. Methods: Using newly available fine-grained data on freshwater plant distributions, we calculated internal homogeneity and cross-boundary heterogeneity among neighbouring ecoregions. We further integrated measures of community dissimilarity to assess whether the degree of within-ecoregion homogeneity and distinctness are driven by their relationships to species replacements and richness differences, and explored how a complex suite of ecogeographical mechanisms and plant life forms affect ecoregion delineation using spatially explicit regression routines. Results: We found a clear geographical patterning of ecoregion robustness for North American freshwater plants, with their communities being more internally homogeneous and more similar to one another in polar and subtropical inland waters. Surprisingly, the degree of internal homogeneity and ecoregion distinctness were almost equally driven by species replacements and richness differences. Considering different life forms, ecoregion delineation performed best for emergent and floating-leaved plants. Finally, within-ecoregion homogeneity and distinctness were best explained by annual mean temperature and terrain ruggedness, respectively, with mean water alkalinity, ecoregion area and Late Quaternary Ice Age legacies having supplementary effects. Main conclusions: Our findings emphasise that geographical regionalisations founded on a particular organismal group are not applicable for all taxa. Our study is a promising starting point for further investigations of geographical delineations for different freshwater taxa. These updated regionalisations can then be used for conserving different biotas in freshwaters, which are currently among the most threatened ecosystems in the world.