Diversity Of Grasses Research Articles

Plant functional diversity shapes soil respiration response to soil moisture availability

Narrowing uncertainties associated with land–atmosphere carbon (C) fluxes is critical for projecting climate futures, but large uncertainties in modeling soil respiration (RS) hinder progress. Difficulties accounting for how biological communities will respond to altered precipitation contribute to those uncertainties, but remain underexplored in situ. In a rainfall and grassland diversity manipulation experiment altering both plant richness and community composition, we measured RS monthly for four growing seasons, along with multiple physical (soil moisture and temperature) and biological drivers (aboveground, root, and microbial biomass) of RS. Relationships between plant richness and RS were dependent on plant community composition and soil moisture conditions. Elevated RS was associated with grass diversity, likely governed by enhanced soil moisture at 12 cm. Microbial biomass was the strongest independent predictor of RS. Though soil moisture was a strong predictor of RS, covariance with precipitation treatments and microbial biomass suggests it operated through multiple indirect pathways. Even after accounting for several RS drivers, plant community composition and richness still accounted for a nontrivial amount of variation in RS. This suggests that unexplored pathways associated with biological complexity (for example, microbial community composition) influence RS. Finally, altered precipitation changed diversity-RS relationships over time, suggesting that soil microbes can respond relatively rapidly to altered precipitation, perhaps due to the diversity of specialist microbes in our initial common soils. Our work demonstrates how biological complexity can interact with physical drivers and changing climates to influence RS in ways currently unaccounted for in models.

Shifts in grasses diversity patterns between two contrasting 40‐year climate periods in tropical dry islands

AbstractGrasses are one of the most successful and dispersed plant families worldwide and their environmental and economic values are widely acknowledged. They dominate the landscape of Cabo Verde, the southernmost and driest archipelago of Macaronesia, and are relevant natural resources for local populations, but a comprehensive evaluation of their distribution patterns is still lacking. In this study, we aim to evaluate the potential effects of climate change using the long‐term data concerning grass distribution in Cabo Verde and the widely recognized climatic variability of this archipelago, which entails a huge irregularity in spatial and temporal rainfall. We identified two contrasting climatic periods (wet, from 1929 to 1968, and dry, from 1969 to 2007) and gathered all the information available from the bibliography, herbaria, and fieldwork concerning spontaneous grass species recorded in Cabo Verde during those two periods, which amounted to 107 taxa. This information was then used to disclose the patterns of grass diversity as related to climatic and topographic variables (altitude and windward vs. leeward aspects). Different altitudinal shifts in the distribution patterns of grass species assemblages and an assemblage specific to the wet period were revealed by comparing the two climatic periods. The role of exposure in delimiting the altitudinal distribution of the various assemblages was highlighted; the trade winds clearly determine the distribution of grass assemblages. We detected shifts in the distribution of grass assemblages according to the climatic periods (related to the macroclimate) and local topographic factors (associated with mesoclimates). Also, functional traits (i.e., annuals vs. perennials, C3 vs. C4 grasses, and tropical vs. temperate species) were found to vary between wet and dry periods, as well as with altitude and with slope aspect. Understanding species distributions and the role of the climatic variability of Cabo Verde is crucial to predicting how climate change will affect them and thus to support effective management and conservation actions.

Spatial phylogenetics of grasses in the Southern Cone provides insights into ecology and evolution of the family in South America

AbstractIn this study, we explored the distributions of grass genera in the Southern Cone (SC) of South America, applying several phylogenetic diversity (PD) metrics and randomization tests. Grasses appear to have been present in South America since their early evolution as tropical understory species more than 60 Ma. During the course of evolution, grasses have adapted to all terrestrial biomes and become one of the most successful plant families on earth. At present, the SC contains nearly all terrestrial biomes and a wide range of humid to arid ecoregions. Analyzing 126.514 point occurrences and four plastid markers for 148 genera (91% of the native grass genera), we found that tropical humid regions hold the highest PD, with no observed bias in branch lengths. These results indicate that niche conservatism dominates the diversity pattern of grasses in the SC. We found significantly low PD in the Dry Chaco and in the Patagonian Steppe, which suggest ecological filtering in both warm and cold arid regions. The Patagonian Steppe also holds significantly longer branches than expected by chance, as the native grass flora is mainly composed of distantly related Pooideae genera with a northern hemisphere origin. Short branches are found in the Uruguayan Savanna, suggesting that these grasslands could be a cradle for grass diversity within the SC. The dated phylogeny supported the current view of a relatively recent evolution of the family within the SC, with most diversification taking place from the middle Miocene and onwards.

Grass Diversity and Status Assessment of Semi-Natural Grassland for Better Management: A Case Study of Rampura Grassland of Dahod District, Gujarat

Grass Diversity and Status Assessment of Semi-Natural Grassland for Better Management: A Case Study of Rampura Grassland of Dahod District, Gujarat

Бобовият компонент на горски садинови ливади в условията на „детелинова година“

A study of the species composition, biological, morphological and productive characteristics of the legume component of forest Chrysopogon gryllus meadows a year with high spring moisture availability was conducted. A very high species diversity of leguminous grasses was found - 17 species from 7 genera. Until the mowing of the meadows, a distinct turnover of species and an almost equal total productivity of dry mass from the legume component per ten-day period was observed. Thus, the productivity of fresh and dry mass of the legume component and, accordingly, the nitrogen fixation levels in the orchard meadows have a stable high level until mowing. The annual clovers can be identified as the legume with the strongest response to increasing moisture availability. A high productivity of mesophytic perennial clover species has also been reported, which significantly increase the fodder value of the grasslands. The species Dorycnium herbaceum and Medicago falcata have the highest productivity of fresh and dry mass when mowing the Chrysopogon gryllus meadows and have the greatest contribution to the forage value of the harvested hay. According to the morphological analysis, the legume component is characterized by a very high variability, both in plant height and in the relative share of leaves and flowers in the formed biomass, which determines its importance for the functional and biological diversity in the studied meadow type. The results are indicative of a great self-recovery potential of the Chrysopogon gryllus meadows in the the foothills of the Central Balkan, as well as a lack of degradation processes under their current mode of use.

Epiphytic microflora and mycotoxin content in meadows-Is plant biodiversity affecting fungal contamination?

Ecosystem services are an important aspect of grasslands utilization; however, they are often contradictory to their main purpose, which is a production of good quality and safe feed. In this study, we evaluated the difference between grass monocultures and species-rich mixtures in terms of epiphytic microflora and mycotoxin contamination levels. We hypothesized that higher species diversity would lead to higher microbial counts, which could lead to higher mycotoxin contamination risk. Differences in epiphytic fungal, yeast and total amount of microorganisms (CFU g -1) depending on the species diversity in the field has been evaluated by cultivation method. Concentration of deoxynivalenol (DON), zearalenone (ZEN) and aflatoxin B1 (AFB1) was measured by ELISA. Results are suggesting that higher total amount of microorganisms were found in monocultures, however, fungal and yeast counts were higher in species-rich mixtures. Higher species diversity of grasses was related to higher total microbial count (TMC) and yeast colonization of phyllosphere. Our results suggest higher risk of fungal phyllosphere colonization of species-rich mixtures with higher biodiversity and therefore higher risk of mycotoxin contamination of such feed.

Local and landscape context affects bee communities in mixed fruit orchards in Southern Thailand

Abstract Bees play an important role by contributing to the pollination of a diverse range of crops and wild plants. However, bees are threatened by deforestation and habitat degradation caused by urbanization and agricultural intensification, which reduce floral and nesting resources. In this study, the effects of local (orchard size, flowering plant abundance and richness and floral abundance) and landscape factors (surrounding agricultural, forest and urban cover) on bee richness and abundance in mixed fruit orchards were determined from 28 mature orchards interspersed along a gradient of landscape complexity. Bees were observed for 15 min in 2 × 2 m plots. We categorized all bees into one of the three groups: (a) honey bees, (b) solitary bees and (c) stingless bees. Several local and landscape factors were found to influence bee richness and abundance. Honey bee abundance was positively affected by orchard size, whereas honey bee richness was not. Stingless bee richness and abundance were positively correlated with floral abundance. Forest cover within a 3‐km radius positively affected solitary bee richness. Solitary bee abundance was positively affected by forest cover within a 3‐km radius and negatively impacted by urban cover within a 1.5‐km radius. In our study area, small forest patches are found in abundance; thus, the high proportion of forest edge, relative to the forest interior, greatly supports solitary bee abundance and richness in this landscape. Moreover, most solitary bees are soil‐nesting species that may be excluded from environments that are converted from natural to anthropogenically developed areas. Recommendations to protect pollinators included conserving existing forest patches, especially forest margins; restoring forest patches within farmland landscapes; maintaining a diversity of herbs and grasses within mixed fruit orchards; establishing live fences composed of diverse plant species and retaining dead trees within farmland. For urban areas, augmenting floral resources in green spaces is suggested.

Analysis of grass diversity of Nilgiri Bisophere Reserve, India, with special emphasis to the endemic species

The grass diversity of Nilgiri Biosphere Reserve (NBR) has been analysed for their distribution, endemism, threat assessment and conservation perspective. Ouf of 412 grass taxa found in NBR, straggering 92 are endemic in India (22.33%) including 14 species strictly endemic to the NBR.

Long-term subtropical grassland plots take a long time to change: Replacement is more important than richness differences for beta diversity.

We studied β diversity of grasses in a subtropical grassland over 60 years in South Africa. We examined the effects of burning and mowing on 132 large plots. We sought to determine the effects of burning and mowing, and mowing frequency, on the replacement of species and the species richness. We conducted the study at Ukulinga, research farm of the University of KwaZulu-Natal, Pietermaritzburg, South Africa (29°24'E, 30°24'S) from 1950-2010. Plots were burned annually, biennially, triennially, and a control (unburned). Plots were mowed in spring, late summer, spring plus late summer, and a control (unmowed). We calculated β diversity, with a focus on replacement and richness differences. We also used distance-based redundancy analyses to examine the relative effects of replacement and richness differences on mowing and burning. We used beta regressions to test for the effect of soil depth and its interactions with mowing and burning. There was no significant change in grass beta diversity until 1995. Thereafter, there were changes in β diversity that demonstrated the primary effects of summer mowing frequency. There was no significant effect of richness differences but a strong effect of replacement post-1995. There was a significant interaction between mowing frequency and soil depth in one of the analyses. Changes in grassland composition took a long time to manifest themselves and were unapparent prior to 1988. However, there was a change in sampling strategy prior to 1988, from point hits to nearest plants, that may also have influenced the rates of changes in replacement and richness differences. Using β-diversity indices, we found that mowing was more important than burning that burning frequency was unimportant, and there was a significant interaction effect between mowing and soil depth in one of the analyses.

Effects of vegetation restoration on soil properties and vegetation attributes in the arid and semi-arid regions of China

Driven by the goal of reversing desertification and recovering degraded lands, a wide range of vegetation restoration practices (such as planting and fencing) have been implemented in China's drylands. It is essential to examine the effects of vegetation restoration and environmental factors on soil nutrients to optimize restoration approaches. However, quantitative evaluation on this topic is insufficient due to a lack of long-term field monitoring data. This study evaluated the effects of sandy steppe restoration and sand dune fixation in the semi-arid desert, and natural and artificial vegetation restoration in the arid desert. It considered soil and plant characteristics using long-term (2005–2015) data from the Naiman Research Station located in the semi-arid region and Shapotou Research Station in the arid region of China's drylands. Results showed the sandy steppe had higher soil nutrient contents, vegetation biomass and rate of accumulating soil organic matter (OM) than the fixed dunes and moving dunes. Soil nutrient contents and vegetation biomass of the natural vegetation of Artemisia ordosica were higher than those of the artificial restoration of Artemisia ordosica since 1956. Artificial restoration had a higher rate of accumulating soil OM, total nitrogen (TN) and grass litter biomass than natural restoration. Soil water indirectly affected soil OM by affecting vegetation. Grass diversity was the main influencing factor on soil OM variance in the semi-arid Naiman desert while shrub diversity was the main factor in the arid Shapotou desert. These findings indicate that sand fixation in the semi-arid desert and vegetation restoration in the arid desert bring benefits for soil nutrient accumulation and vegetation improvement, and that natural restoration is preferable to artificial restoration. Results can be used to formulate sustainable vegetation restoration strategies, such as encouraging natural restoration, considering local resource constraints, and giving priority to restoring shrubs in arid areas with limited water.

Reproductive height determines the loss of clonal grasses with nitrogen enrichment in a temperate grassland

Tall clonal grasses commonly display competitive advantages with nitrogen (N) enrichment. However, it is currently unknown whether the height is derived from the vegetative or reproductive module. Moreover, it is unclear whether the height of the vegetative or reproductive system regulates the probability of extinction and colonization, and determines species diversity. In this study, the impacts on clonal grasses were studied in a field experiment employing two frequencies (twice a year vs. monthly) crossing with nine N addition rates in a temperate grassland, China. We found that the N addition decreased species frequency and increased extinction probability, but did not change the species colonization probability. A low frequency of N addition decreased species frequency and colonization probability, but increased extinction probability. Moreover, we found that species reproductive height was the best index to predict the extinction probability of clonal grasses in N-enriched conditions. The low frequency of N addition may overestimate the negative effect from N deposition on clonal grass diversity, suggesting that a higher frequency of N addition is more suitable in assessing the ecological effects of N deposition. Overall, this study illustrates that reproductive height was associated with the clonal species extinction probability under N-enriched environment.

Long-Term Anthropogenic Management and Associated Loss of Plant Diversity Deeply Impact Virome Richness and Composition of Poaceae Communities.

Modern agriculture has influenced plant virus emergence through ecosystem simplification, introduction of new host species, and reduction in crop genetic diversity. Therefore, it is crucial to better understand virus distributions across cultivated and uncultivated communities in agro-ecological interfaces, as well as virus exchange among them. Here, we advance fundamental understanding in this area by characterizing the virome of three co-occurring replicated Poaceae community types that represent a gradient of grass species richness and management intensity, from highly managed crop monocultures to little-managed, species-rich grasslands. We performed a large-scale study on 950 wild and cultivated Poaceae over 2 years, combining untargeted virome analysis down to the virus species level with targeted detection of three plant viruses. Deep sequencing revealed (i) a diversified and largely unknown Poaceae virome (at least 51 virus species or taxa), with an abundance of so-called persistent viruses; (ii) an increase of virome richness with grass species richness within the community; (iii) stability of virome richness over time but a large viral intraspecific variability; and (iv) contrasting patterns of virus prevalence, coinfections, and spatial distribution among plant communities and species. Our findings highlight the complex structure of plant virus communities in nature and suggest the influence of anthropogenic management on viral distribution and prevalence. IMPORTANCE Because viruses have been mostly studied in cultivated plants, little is known about virus diversity and ecology in less-managed vegetation or about the influence of human management and agriculture on virome composition. Poaceae (grass family)-dominated communities provide invaluable opportunities to examine these ecological issues, as they are distributed worldwide across agro-ecological gradients, are essential for food security and conservation, and can be infected by numerous viruses. Here, we used multiple levels of analysis that considered plant communities, individual plants, virus species, and haplotypes to broaden understanding of the Poaceae virome and to evaluate host-parasite richness relationships within agro-ecological landscapes in our study area. We emphasized the influence of grass diversity and land use on the composition of viral communities and their life history strategies, and we demonstrated the complexity of plant-virus interactions in less-managed grass communities, such as the higher virus prevalence and overrepresentation of mixed virus infection compared to theoretical predictions.

Grass-microbial inter-domain ecological networks associated with alpine grassland productivity.

Associations between grasses and soil microorganisms can strongly influence plant community structures. However, the associations between grass productivity and diversity and soil microbes, as well as the patterns of co-occurrence between grass and microbes remain unclear. Here, we surveyed grass productivity and diversity, determined soil physicochemical, and sequenced soil archaea, bacteria and fungi by metabarcoding technology at 16 alpine grasslands. Using the Distance-decay relationship, Inter-Domain Ecological Network (IDEN), and Mantel tests, we investigated the relationship between grass productivity, diversity and microbial diversity, and the patterns of co-occurrence between grass and microbial inter-domain network in alpine grassland. We found the archaea richness, bacteria richness and Shannon, and fungi α-diversity were significantly negatively correlation with grass diversity, but archaea and bacteria diversity were positively correlation with grass productivity. Moreover, an increase in microbial β-diversity was observed along with increased discrepancy in grass diversity and productivity and soil variables. Variance partitioning analysis suggested that the contribution of grass productivity on microbial community was higher than that of soil variables and grass diversity, which implies that microbial community was more related to grass productivity. Inter-Domain Ecological Network showed that the grass species formed complex and stable ecological networks with some bacterial, archaeal, and fungal species, and the grass-fungal ecological networks showed the highest robustness, which indicated that soil fungi could better co-coexist with aboveground grass in alpine grasslands. Besides, the connectivity degrees of the grass-microbial network were significantly positively correlated with grass productivity, suggesting that the coexistence pattern of grasses and microbes had a positive feedback effect on the grass productivity. The results are important for establishing the regulatory mechanisms between plants and microorganisms in alpine grassland ecosystems.

CLASIFICACIÓN Y CARACTERIZACIÓN DE LOS SISTEMAS FAMILIARES DE PRODUCCIÓN BOVINA DE LA REGIÓN FRAILESCA DE CHIAPAS, MEXICO, CON BASE EN EL APORTE DE LA GANADERÍA AL INGRESO FAMILIAR

<p><strong>Background: </strong>In recent decades, many peasant regions of southeastern Mexico, have undergone an expansion of cattle raising. This has led to farmers transitioning from crop agriculture toward mixed production or specializing in cattle raising. Characterizing livestock systems using a multidimensional perspective allows for identifying strategies for increasing their sustainability. <strong>Objective:</strong> To classify and characterize family cattle farming systems (FCFS) of the Frailesca region of Chiapas, Mexico taking into account the contribution of cattle raising to family income, and using a multidimensional perspective. <strong>Methodology:</strong> Eighty family units in two areas of the Frailesca region - valley (40) and highlands (40) - were evaluated. Information was obtained through application of questionnaires to farmers. According to the percentage of contribution of cattle raising to family income, a K-means clustering analysis was carried out in each area to differentiate FCFS. Average values of technical, economic, environmental, and social indicators were compared among systems using ANOVA or Kruskall Wallis tests. <strong>Results:</strong> Two FCFS were identified in each of two areas of the Frailesca region: (I) mixed family systems (MFS) and (II) family systems specialized in cattle raising (FSSC). Average percentages of contribution of cattle raising to family income were: (1) valley MFS = 32.5%; (2) valley FSSC = 80.5%; (3) highland MFS = 38.5%; and (4) highland FSSC = 71.7%. The valley FSSC followed an intensive-technified cattle raising with high use of external inputs and had the highest values of the economic indicators: calves produced per ha, milk production per cow, and net margin per hectare. The valley MFS practiced semi-intensive-technified cattle raising with low use of external inputs which led it had lower economic profitability than that of the valley FSCC. In both highland systems, farmers followed extensive cattle raising with low use of external inputs. For the economic dimension, these were similar to that of the valley MFS. Nevertheless, for the environmental dimension both highland systems were better (diversity of grasses, backyard animals, cattle breeds, and woody fodder crops) than the valley systems. Particularly, the highlands MFS had the greatest proportion of forested land and grasslands with scattered trees, as well as the abundance of wild fauna. For the social dimension, both the FSSC had a higher level of technical assistance and training, less dependence on subsidies, and a greater capacity to cover their basic purchased-food costs than the two MFS. The highlands MFS had the highest number of family beneficiaries, while the highlands FSSC had a higher level of membership in farmers´ organizations than did both types of valley systems. <strong>Implications: </strong>The valley farmers should reduce their environmental impacts and maintain and even increase productivity, in the case of the mixed family system. The highlands farmers should increase productivity, and reduce their dependence on subsidies. <strong>Conclusions:</strong> In order to overcome the multidimensional limitations and increase the sustainability of family cattle raising systems, it is necessary that external social actors promote agroecology and silvopastoral systems, as well as the famers´ co-responsibility and active participation along the process. </p>

Diversity of Grasses from Rehekuri Sanctuary, Karjat, Dist. Ahmednagar, M.S., India

Grasses constitute a natural homogenous group of plants belonging to the family Poaceae (Gramineae). They are economically the most important of all flowering plants because of their nutritious grains and soil-forming function and they have the most-widespread distribution and the largest number of individuals. During extensive field survey of grasses samples were a total number of 41 genera 66 different grass species have been collected, identified, described and illustrated from the Rehekuri Sanctuary, Karjat. It is found that out of 41 genera of study area, 26 have only one species each (monotypic) it is also noted that the genera which are represented in India by a single species also occur in this region. These are Achrachne racemosa and Apluda mutica. It also shows that 06 genera have two species each, 03 have 03 species each, 03 have 04 species and 01 genera have 07 species. The poaceae family showed Setaria, Aristida, Brachiaria and Eragrosti were found most dominant genera and luxuriantly grow in rainy season and cold climatic conditions. This is first time report from Rehekuri Sanctuary, Karjat of Ahmednagar district of Maharashtra

北京地区油松人工林不同演替类型空间结构对林下植被及土壤的影响

PDF HTML阅读 XML下载 导出引用 引用提醒 北京地区油松人工林不同演替类型空间结构对林下植被及土壤的影响 DOI: 10.5846/stxb202112143542 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 北京市园林绿化局项目"北京市国有林场精准提质"（20210618） Effects of spatial structure on understory vegetation and soil properties in Pinus tabuliformis plantation of different succession types in Beijing Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:以北京地区油松（Pinus tabuliformis）人工林不同演替类型林分为研究对象，研究油松纯林、油松-栓皮栎（Quercus variabilis）混交林和栓皮栎纯林三种不同演替类型林分的空间结构、林下植被和土壤水分的变化规律及其相互作用关系。结果表明：（1）林分水平及垂直空间结构、草本层物种多样性、更新幼树生长、土壤持水和透气性能等指标在三种不同演替类型林分间差异显著（P<0.05），林分空间结构参数中的角尺度、林层指数和开敞度显著影响了各类型林分的灌草多样性，混交度、林层指数和大小比数显著影响了更新幼树的生长，混交度和林层指数显著影响了土壤水分的变化（P<0.05）。（2）松栎混交林灌草生物量、天然更新幼树的生长以及土壤水分物理状况均好于纯林，并主要受林分混交度和林层指数的共同作用。（3）各演替类型林分内均存在栓皮栎更新幼树，混交林栓皮栎更新幼树数量最多、长势最好，对林地资源的竞争最为激烈。因此，可以通过调整林分空间结构实现种间关系及林地资源的调控，以充分发挥森林生态系统的各项功能与价值。 Abstract:Using different succession types of Pinus tabuliformis plantation in the Beijing area as the research object, this study investigated the change rules and interaction of stand spatial structure, understory vegetation, and soil water of three different succession types:Pinus tabuliformis pure forests, Pine-Quercus mixed forests, and Quercus variabilis pure forests. The results were as follows. (1) There were significant differences in horizontal and vertical stand spatial structure, species diversity of herbaceous layer, saplings growth, and soil water physical properties among the three different succession types (P<0.05). In addition, the angle index, stand layer index and opening degree index of stand spatial structure parameters significantly affected the shrub and grass diversity of each type of stand (P<0.05), while the mingling degree, stand layer index and neighborhood comparison significantly affected the growth of saplings (P<0.05), and the mingling degree and stand layer index significantly affected the change of soil water (P<0.05). (2) The biomass of shrub and grass, saplings growth, and the physical condition of soil water were all the better within the mixed forest than in the pure forest and were mostly influenced by the mingling degree and the stand layer index. (3) The natural regeneration saplings of Quercus variabilis were observed in all succession types, with mixed forest having the most saplings and the best growth and the most intensive competition for forest resources. Therefore, interspecific relationships and forest resources can be regulated by adjusting the spatial structure of stand, so as to give full play to the functions and values of forest ecosystem. 参考文献 相似文献 引证文献

Grass Flora along Altitudinal Gradient of the Phulchoki Hill, Central Nepal

Phulchoki hill on the southern part of Kathmandu Valley (1550-2750 m) presents a unique opportunity to study the diversity of grasses along the altitudinal gradient. During the present study, 73 species of grasses belonging to 5 sub families, 16 tribes and 48 genera were recorded, out of which 28 species are new to this area. Among the recorded species 89% of the species were terrestrial, 7% lithophytes and remaining 4% aquatic. The lowest elevation (1550-1950 m) has highest diversity with 49 species whereas the topmost band (2351-2750 m) has least diversity with only 19 species. The total species richness of grass has decreasing trend along the altitudinal gradient of species, with r2 =0.97 and p=0.04, which indicates significant relation.

Ecological Distribution Patterns of Wild Grasses and Abiotic Factors

Documentation the relative influence of ecological dynamics on species diversity patterns can help us better understand spatial distribution patterns and devise a systematically comprehensive base for carrying out environmental explorations. The current attempt aimed at exploring the distribution patterns, diversity and richness of wild grasses with respect to climatic dynamics in the Gujrat district of Punjab, Pakistan. For this purpose, we applied the randomized sample method and sampled a total of 90 sites across the Gujrat district between 2019 and 2021 to document data on wild grasses and related ecological conditions. After assessment of the significant value index of each grass species with ecological records, we evaluated the data by ordination and cluster analysis. A total of 57 wild grasses from 37 genera were documented from the Gujrat district. The leading genera were Brachiaria, Cenchrus and Setaria, each accounting for 7.02% of all documented species, followed by Aristida and Panicum, each representing 5.76% of the species. Dactyloctenium, Dichanthium, Eragrostis, Polypogon, Poa and Saccharum each accounted for 5.26% of the species, and Digitaria, Pennisetum, Eragrostis, Chrysopogon Poa and Setaria each accounted for 3.51% of the species. Other genera each had a single species. Among all grasses, 75.44% of the species were native and 24.56% species were exotic and introduced to the study area. The leading life forms were therophytes (56.14%), followed by hemicryptophytes (42.11%) and geophytes (1.75%). Microphylls, with a 54.39% share, dominated the leaf size spectra of the wild grasses flora in this research. Other frequent classes included nanophylls (21.05%), macrophylls (19.3%) and leptophylls (5.26%). Flowering phenology of wild grasses showed that mainly species at the flowering phase were recorded during the months of June to August (40.35%) and July to September (19.29%). By applying Ward’s agglomerative clustering method, we classified the ninety transects into four major groups. Ordination analysis showed that different ecological factors had significant (p ≤ 0.002) effects on vegetation relations. The present endeavor provides a basic way to understand the impacts of ecological variables on the structure, diversity, composition and associations of wild grasses, which are helpful to improve the scientific-informed conservation and management measures for the environmental reestablishment of degraded habitat in the studied region.

Grass species diversity response to brush packing in semi-arid rangelands of South Africa

Most semi-arid savannahs in South Africa are being degraded by bush encroachment, resulting in a decline in biodiversity. Four restoration treatments consisting of bush clearing, brush packing, reseeding and a combination of clearing, reseeding and brush packing were tested. Grass diversity was measured in a communal and conservation area using the difference between the baseline year (2017) and two years after restoration (2019). The effect of brush packing versus non-brush packing was further assessed analysing indicator species and the composition of grass species communities. The brush packing and reseeding had a less pronounced effect on grass richness and diversity at the conservation area, however a large effect on grass richness (p < 0.05) at the communal area. The results suggest that brush packing promotes grass diversity under high grazing pressure in communal areas compared to conservation areas. Species evenness was positively affected by brush packing at the communal area, while abundance was not significantly affected by the treatments. Furthermore, the results showed that the grass composition was dissimilar between brush packed and un-brush packed treatments, in the communal area. A higher number of decreasers and perennial grass species were identified in the brush packing treatments compared especially to the communal area.

Molecular, cellular, and developmental foundations of grass diversity.

Humans have cultivated grasses for food, feed, beverages, and construction materials for millennia. Grasses also dominate the landscape in vast parts of the world, where they have adapted morphologically and physiologically, diversifying to form ~12,000 species. Sequences of hundreds of grass genomes show that they are essentially collinear; nonetheless, not all species have the same complement of genes. Here, we focus on the molecular, cellular, and developmental bases of grain yield and dispersal-traits that are essential for domestication. Distinct genes, networks, and pathways were selected in different crop species, reflecting underlying genomic diversity. With increasing genomic resources becoming available in nondomesticated species, we anticipate advances in coming years that illuminate the ecological and economic success of the grasses.