Growth Formation Research Articles

A Trade-Off Between Leaf Carbon Economics and Plant Size Among Mangrove Species in Dongzhaigang, China.

Plant size is closely linked to its leaf trait characteristics, which are essential for determining its form and function. These relationships constitute a fundamental component of the global spectrum of plant diversity. Despite this, the size-trait relationships in coastal mangroves have often been overlooked, with a common assumption that they would mirror those found in terrestrial tropical trees. However, recent studies have begun to challenge this assumption, revealing unique adaptations and trait variations in mangroves that are influenced by their specific environmental conditions, such as salinity and nutrient availability. In this research, we investigated the leaf structural traits, plant height, and diameter at breast height or basal height (DBH) of 10 shrub and tree species. This study was carried out along an intertidal gradient within a mangrove forest located in Southeast China. We found that leaf traits differed significantly between shrubs and trees in their response to intertidal gradients, indicating that different species have evolved specific adaptations to thrive in their respective intertidal zones. This insight can help us decipher the selective pressures that have shaped trait evolution. Among all species, leaf carbon (C) economics (leaf dry mass content, leaf mass per area, and leaf density) decreased significantly with increasing plant height and DBH. For each growth form and intertidal zone, the relationships between plant size (height or DBH) and leaf C economics traits were consistent with those in the pooled dataset. Our study reveals that mangrove plants exhibit size-related adjustments in leaf C economic strategies, indicating that plant size potentially acts as a proxy for the "slow-fast" continuum of plant performance. This discovery is pivotal for advancing our understanding of plant functional ecology and for enhancing the precision of global C cycle models, which are highly responsive to perturbations in atmospheric CO2 and climate change.

Growth form variations of Amaranthus hybridus L. biotypes with EPSPS mutations

AbstractSeveral Amaranthus hybridus L. biotypes present single and triple amino acid substitutions in EPSPS (5‐enolypyruvylshikimate‐3‐phosphate synthase). In resistant and tolerant species to glyphosate, differential susceptibility and alterations in the EPSPS sequence could cause modifications in their morphological–structural characteristics, an issue that is unknown for biotypes of A. hybridus. The aim of the work was to determine the susceptibility to glyphosate, the presence of mutations in EPSPS and the growth form in four biotypes of this weed from north‐central Argentina. To carry out this, a dose–response assay was conducted, to determine the presence of mutations in the EPSPS, DNA was extracted, amplified and sequenced, and finally, to evaluate the morphological–structural variations, the growth form was analysed. Our findings revealed that Ah03, Ah07 and Ah36 biotypes had resistance factors of 22 to 118. The EPSPS sequence remains unaltered in the Ah39 biotype, leading it to be considered a susceptible biotype. Biotypes Ah03 and Ah36 had heterozygous changes in the DNA sequence resulting in amino acid substitutions at positions 102, 103 and 106 being considered resistant biotypes, whereas in Ah07 some individuals showed unaltered DNA sequences and others exhibited heterozygous changes. The growth form was quantitatively different between biotypes, standing the most susceptible biotype that produced more seeds and required less thermal time for the appearance of the terminal inflorescence. The present investigation provides new evidence that resistant biotypes with the triple DNA mutation exhibit variations in the growth form compared to susceptible biotypes of this weed.

Classified Plant Al-Dhahiriya in the South of Palestine

We studied plant species of Dhahiriya in the period between January to October 2021, and January to Jun 2024, due to the importance of plants in that vital part of Palestine, which is located in southern Palestine, including that region’s climate, and unique plants that represent of the Mediterranean region plants, North Africa, Sinai desert, Negev, Dead Sea, and Red Sea. It used the Braun-Blanquet (1979) method for the identification of plants. Moreover, Plants have been studied in Dhahiriya, located in southern Palestine. A total of 770 species from 70 families were identified, of which 86 (11.16%) are endemic. The plant families with the highest representation were Asteraceae (14.54%), Fabaceae (14%), Poaceae (7.41%), and Lamiaceae (5.19%). Regarding plant life forms, Therophytes account for 47%, Hemicryptophytes for 20.35%, Shrubs or Chamaephytes for 14.05%, and Trees or Phanerophytes for 9.05%, with a notable increase in spring.

Volume-based selection in Pinus pinaster Aiton breeding: evaluating resistance to Bursaphelenchus xylophilus (Steiner & Buhrer) Nickle and wood properties

Key messageGenetic parameter estimates at age 12 years for trunk volume in Pinus pinaster displayed low to moderate heritability for growth and stem form, whereas wood properties showed high heritability. No correlation was detected between resistance to the nematode Bursaphelenchus xylophilus and growth, stem form, or wood properties. However, certain families stood out, showing favorable values across all traits, including resistance to the nematode.ContextThe breeding program for Pinus pinaster should advance towards a second-generation breeding population based on volume, stem form, and resistance to Bursaphelenchus xylophilus, with the challenge of incorporating novel traits of importance.AimsWe focused on assessing the genetic parameters of growth, stem form, wood properties, and resistance to B. xylophilus as well as exploring the relationship between these traits.MethodsWe evaluated 116 half-sib families at three ages (7, 12, and 17 years) in seven progeny trials established in 2005, analyzing growth, stem form, and wood traits. Resistance to B. xylophilus was assessed in 91 of the 116 half-sib families at age 2 by artificial inoculation tests under greenhouse conditions.ResultsAdvancing the selection age to 12 years proved to be feasible for volume selection in Galician P. pinaster. All traits, including resistance to B. xylophilus, showed potential for genetic improvement. Remarkably, resistance to B. xylophilus was not correlated to any other trait.ConclusionExcluding the most susceptible families to B. xylophilus from the Galician P. pinaster breeding program would not result in a significant decrease in volume, stem form, or wood properties.

Urban Cemeteries as Biodiversity Refuges: A Comparative Study of Plant Ecobiomorphs in Central Kazakhstan

Cemeteries are often overlooked in ecological studies, yet they represent unique urban microhabitats that contribute to the preservation of diverse plant species, including those adapted to various ecological niches. This study aimed to assess the species composition, ecological classifications, and abundance of vascular plants in the cemetery and surrounding areas to explore cemeteries’ role in conserving plant ecobiomorph diversity in arid climates. This study identified 79 plant species from 23 families within the cemetery compared with 31 species from 11 families in the surrounding area. The plant community in the cemetery was dominated by mesophytes, suggesting favorable and stable conditions for plant growth, while xerophytes were more common in the surrounding areas, indicating harsher, drier conditions. The diversity of plant life forms, including perennial herbs, shrubs, and trees, was significantly higher within the cemetery, indicating a more complex and resilient ecosystem. Our study demonstrates that cemeteries act as vital refuges for plant biodiversity. They offer significantly higher species diversity and more complex ecosystem structures compared with the surrounding areas. These findings emphasize the critical role cemeteries play in urban biodiversity conservation, particularly in increasingly arid environments.

Grassland albedo as a nature-based climate prospect: the role of growth form and grazing

Abstract Nature-based solutions for mitigating climate change focus largely on land management to reduce carbon emissions and enhance carbon sequestration. Tree planting, commonly advocated for carbon offset, threatens grassland biodiversity and may induce positive radiative forcing (warming) by lowering albedo. Before making decisions about land-use changes in grasslands, an understanding of the fine-scale albedo of grassy versus woody vegetation is needed. Existing satellite-based albedo products offer global coverage with temporally fine, but spatially coarse, resolution, whereas fine-scale in situ grassland albedo data are sparse. We examined the hypotheses that albedo varies seasonally between grass type patches, between shrub and grass patches, and with grazing at the patch scale. Using a tripod-mounted albedometer, we quantified albedo of seven distinct grassland patches in South Africa’s eastern Karoo during early and late dormancy and growing seasons. Patches included intensely-grazed grazing lawn (Cynodon dactylon), grazed and less-grazed red tussock grass (Themeda triandra), grazed and less-grazed white tussock grass (Eragrostis lehmanniana), shrub (Pentzia incana) encroached grass, and bare ground. Season influenced albedo in all patches and, additionally, we found strong differences for the same period between years due to varying rainfall and temperature patterns. For grass-dominated patches, albedo differences were most pronounced during early dormancy, likely due to an effect of grass inflorescences. Albedo of intensely-grazed grazing lawns was consistently higher than other patches, except during early dormancy when white tussock grass albedo was equally high. We found no albedo difference between grazed and less-grazed tussock patches of either red or white grass. Shrub-encroached patches exhibited consistently lower albedo than other patches. Our findings underscore the nuanced relationship between grassland patches and albedo, with shrub encroachment, proposed afforestation, and certain grasses possibly increasing warming potential through reduced albedo. As climate initiatives extend into grasslands, understanding these patterns is essential for climate change mitigation and grassland conservation.

Leaf architecture and functional traits for 122 species at the University of California Botanical Garden at Berkeley.

The dataset contains leaf venation architecture and functional traits for a phylogenetically diverse set of 122 plant species (including ferns, basal angiosperms, monocots, basal eudicots, asterids, and rosids) collected from the living collections of the University of California Botanical Garden at Berkeley (37.87° N, 122.23° W; CA, USA) from February to September 2021. The sampled species originated from all continents, except Antarctica, and are distributed in different growth forms (aquatic, herb, climbing, tree, shrub). The functional dataset comprises 31 traits (mechanical, hydraulic, anatomical, physiological, economical, and chemical) and describes six main leaf functional axes (hydraulic conductance, resistance and resilience to damages caused by drought and herbivory, mechanical support, and construction cost). It also describes how architecture features vary across venation networks. Our trait dataset is suitable for (1) functional and architectural characterization of plant species; (2) identification of venation architecture-function trade-offs; (3) investigation of evolutionary trends in leaf venation networks; and (4) mechanistic modeling of leaf function. Data are made available under the Open Data Commons Attribution License.

Patterns and Drivers of Pollen Temperature Tolerance.

Pollen, a pivotal stage in the plant reproductive cycle, is highly sensitive to temperature fluctuations, impacting seed quality and quantity. While the importance of understanding pollen temperature limits (Tmin, Topt, Tmax - collectively PTLs) is recognized, a comprehensive synthesis of underlying drivers is lacking. Here, we examined PTLs, correlating them with vegetative tissue thermotolerance and assessing variability at the intra- and interspecific levels across 191 species with contrasting phylogeny, cultivation history, growth form and ecology. At the species level, the PTLs range from 9.0 to 42.4°C, with considerable differences among individual species. Vegetative tissue showed greater tolerance to both low and high temperatures than pollen. A significant, though weak, correlation was observed between PTLs and leaf temperature tolerance. Pollen heat tolerance was independent of that in leaves and stems. The greatest intraspecific variability was observed in pollen cold tolerance (Tmin), followed by Topt and Tmax. Phylogenetic analysis revealed family-level conservation in all three pollen temperature tolerance measures. Climate emerged as a significant PTL driver of pollen cold tolerance, with species from colder and stable climates exhibiting enhanced cold tolerance. Cultivated and wild species did not differ in their pollen temperature tolerances. Herbaceous plants showed higher tolerance to high temperatures compared to shrubs and trees, potentially reflecting divergent thermal conditions during anthesis. This study provides the first formal analysis of complex relationships between pollen temperature limits, plant characteristics and environmental factors, providing crucial insights into climate change impacts on plant reproduction.

Simulation of fatigue crack growth in aluminium alloy 7075-T7351 under spike overload and aircraft spectrum loading

The trend towards virtual testing and digital-twin assisted management means that the accurate and reliable simulation of fatigue crack propagation behaviour is more important than ever. Reliable but conservative approaches to support this are in widespread use in the aerospace industry. Nevertheless, the conservatism comes at a significant cost in terms of reduced structural life and an increased ongoing inspection requirement and, as such leads to questions about the economic burden of these approaches. Recent comparisons between blind predictions and test results revealed the extent of the issue for cracking in aluminium alloy 7075-T7351 coupons with configuration and loading representative of military transport aircraft wing skins. The current models were generally conservative by a factor of two or more in terms of crack propagation life. This suggested that there was significant scope to improve the modelling to better reflect all the complex contributing factors. The current work has investigated the issue of changes in the crack front constraint as the crack progresses from a state of high constraint (close to plane strain) to a lower constraint (approaching plane stress). This issue was investigated both experimentally and with the development of an improved analytical model. A test program was conducted on several specimens, loaded under constant-amplitude, constant-amplitude with spike-overloads and a variable amplitude spectrum. Crack-opening stress levels were measured at key points in the tests and the results were used to develop and evaluate improved modelling approaches. The improved model was generally able to predict crack growth within about ± 30 % of that demonstrated along with the correct form of the crack growth, which is a significant advance and will lead to reduced costs and increased safety.

Kontribusi Mahasiswa dalam Merealisasikan Kreativitas Diri Melalui Model Pembelajaran Special Event di Politeknik Pariwisata Prima Internasional

Creativity is an activity that positively impacts human growth and development. One form of human growth and development is the output of creativity through an activity and a product. EPHICS emerged as a form of creativity from international prime tourism polytechnic students and involved students. Qualitative descriptive methods followed by observation and visualization of layouts assisted by the interview process and documentation to collect data related to research. As a result of this activity program, students make a field learning model that can continue to hone creativity and is expected to develop EPHICS even better. SWOT analysis and analysis of the concept of event implementation become the basis for the activity evaluation process. The evaluation results obtained after each activity is completed are used as material for improvement in the implementation of future EPHICS activities to make it even better.

Unraveling Magnet Structural Defects in Permanent Magnet Synchronous Machines—Harmonic Diagnosis and Performance Signatures

Rare-earth-based permanent magnets (PMs) have a vital role in numerous sustainable energy systems, such as electrical machines (EMs). However, their production can greatly harm the environment and their supply chain monopoly presents economic threats. Alternative materials are emerging, but the use of rare-earth PMs remains dominant due to their exceptional performance. Damage to magnet structure can cause loss of performance and efficiency, and propagation of cracks in PMs can result in breaking. In this context, prolonging the service life of PMs and ensuring that they remain damage-free and suitable for re-use is important both for sustainability reasons and cost management. This paper presents a new harmonic content diagnosis and motor performance analysis caused by various magnet structure defects or faults, such as cracked or broken magnets. The proposed method is used for modeling the successive physical failure of the magnet structure in the form of crack formation, crack growth, and magnet breakage. A surface-mounted permanent magnet synchronous motor (PMSM) is studied using simulation in Ansys Maxwell software (Version 2023), and different cracks and PM faults are modeled using the two-dimensional finite element method (FEM). The frequency domain simulation results demonstrate the influence of magnet cracks and their propagation on EM performance measures, such as stator current, distribution of magnetic flux density, back EMF, flux linkage, losses, and efficiency. The results show strong potential for application in health monitoring systems, which could be used to reduce the occurrence of in-service failures, thus reducing the usage of rare-earth magnet materials as well as cost.

Speciation and evolution of growth form in Adesmia D. C. (Dalbergieae, Fabaceae): the relevance of Andean uplift and aridification.

The Andean uplift and the concomitant aridification drove the rapid diversification of several plant lineages that were able to colonize warmer and drier habitats at low elevations and wetter and colder habitats at high elevations. These transitions may be facilitated by shifts in plant strategies to cope with drought and cold, which in turn can trigger episodes of accelerated species diversification. Here, we used four nuclear DNA markers to infer phylogenetic relationships of 80 Adesmia species of annuals, perennial herbs, shrubs and small shrubs that occur in Chile and Argentina. We reconstructed ancestral states for area, climatic niche and growth form to explore how Andean uplift and aridification promoted Adesmia diversification. We also performed logistic and linear regression analyses between different components of growth form (life span, woodiness and plant height) and climate. Finally, we estimated speciation rates across the phylogeny. Our results suggest that the ancestor of Chilean Adesmia was a perennial herb that probably originated in the high Andes of northern and central Chile. The low elevations of Central Chile were colonized in the late Miocene, whereas the high latitudes of Patagonia and the hyperarid coastal Atacama Desert were colonized repeatedly since Pliocene by lineages with different growth forms. Multiple and bidirectional transitions between annual and perennial habits and between herbaceous and woody habits were detected. These shifts were not correlated with climate, suggesting that the different growth forms are alternative and successful strategies to survive unfavorable seasons of both desert and high Andes. Net diversification analysis indicated a constant rate of diversification, suggesting that the high species diversity of Adesmia that occur in Chile is due to a uniform speciation process rather than to accelerated episodes of speciation.

Seagrass space occupation efficiency is key for their role as ecosystem engineers and ecological indicators

Studies for the preservation of seagrass beds biotopes have met difficulties in establishing appropriate methods assessing their health. We tested the efficiency of space occupation by seagrasses scattered worldwide (dgrass index), which proved to be dependent on clonal growth form and morphometric plasticity. dgrass correlated with the above-ground to below-ground biomass ratio. However, the latter was misleading when high ratios resulted from low below-ground biomass. Nutrient Posphate-limitations were revealed in situations of theoretical Nitrogen-limitation. Enhanced nutrient supply benefitted seagrasses only up to a threshold after which it became detrimental. Better nurtured, healthier meadows with denser canopies increased the organic matter in the sediment and had associated greater abundances of benthic macrofauna. Hence, seagrass biotopes could benefit from moderate anthropogenic nutrient additions. However, organic matter above ≈6% and/or reduced riverine discharges (dams upstream and climate-change-related droughts) were detrimental to healthy meadows, jeopardizing ecosystem services such as macrofauna abundances and carbon sinks.

Changes in Leaf Functional Traits with Leaf Age for Coexisting Woody Species in Temperature Forest of Northern China

Leaf-trait variation has traditionally been focused on both within and among species along environmental gradients, while leaf age has received less attention. By measuring leaf morphological, stomatal, and stoichiometric traits of 40 coexisting woody species in temperate forest in northern China, we analyzed their variation pattern and the correlations among different plant life forms and leaf age. We found that leaf age has significant effects on leaf functional traits. The young leaves of both shrub and tree species revealed a lower stoma density (SD) and a higher stoma length (SL), stoma width (SW), and leaf N content (LNC) than mature leaves. Shrub species have a higher SLA and SD than tree species for both young and mature leaves. The traits of young leaves generally revealed a higher variation than those of mature leaves. Although correlations between traits are similar between young leaves and mature leaves, the slopes of the SLA–SD and SD–LNC relationships were significantly affected by leaf age. These findings elucidate the adaptive changes of leaf traits during leaf maturation and underscore the trade-off between stomatal safety and efficiency, as well as the trade-off between leaf hydraulic and economic traits in temperate woody species during leaf development. We conclude that variation in leaf traits with age may play a potentially important role in understanding the ecological function of woody species in temperate forests.

Regulated cleavage and translocation of FERONIA control immunity in Arabidopsis roots.

Plant roots exhibit localized immunity (LI) mainly in the transition zone (TZ) and elongation zone (EZ). Plasma membrane-localized receptor-like kinases (RLKs) can mediate the plant's response to rhizosphere bacteria. However, how RLKs are involved in triggering LI in roots remains unclear. Here we identified dual actions for the RLK FERONIA (FER) in the LI response of Arabidopsis (Arabidopsis thaliana). The FER cytoplasmic domain is cleaved and translocated to the nucleus (FERN) to activate LI in the TZ and EZ in response to colonization by beneficial and pathogenic bacteria. In the absence or cessation of bacterial infection, full-length FER is plasma membrane-localized to maintain growth. Upon colonization and invasion by a high titre of bacteria, mature RAPID ALKALINIZATION FACTOR23 peptide accumulates and activates the matrix metalloproteinase At2-MMP, which triggers FER cytoplasmic domain cleavage specifically in the TZ and EZ to activate LI. This work demonstrates that two molecular forms of a single RLK balance growth and immunity via LI activation in Arabidopsis roots.

Characteristics of Phytoplankton Community Structure in Lakes of Wetlands Dominated by Different Aquatic Plants and Its Driving Factors

In wetland ecosystems, small shallow lakes are critical transition zones of land and water, which are usually dominated by aquatic plants with different growth forms. However, the differences and key influencing factors of phytoplankton communities in shallow lakes dominated by different aquatic plants are unclear. On this basis, nine surveys were conducted at five sampling sites of three lakes in Zhangye National Wetland Park from June to November in 2022, which were respectively dominated by the emergent Phragmites australis （LL）, the submerged Potamogeton perfoliatus （CL）, and the floating-leaved Nymphaea tetragona （SL）. During the study period, the three lakes showed obvious habitat differences. A total of 237 species of phytoplankton in seven phyla and 93 genera were identified in the three lakes, including 189 species, 151 species, and 147 species in the LL, CL, and SL lakes, respectively. Among them, Ulnaria acus, Scenedesmus quadricauda, Achnanthidium minutissimum, Nitzschia stagnorum, Navicula radiosa, and Gymnodinium aeruginosum were shared dominant species of all three lakes, indicating that they had strong environmental adaptability, whereas Navicula lanceolala, Encyonopsis cesatii, and Eunotia diodon and Cymbella aequalis were only dominant in the CL, LL, and SL lakes, respectively. Simultaneously, these dominant algae appeared with obviously distinct statuses of niche width, niche overlap, and interspecific correlation among the three lakes. Using principal coordinate analysis （PCoA） and permutational multivariate analysis of variance （PERMANOVA）, significant differences were found in algal community composition among the three lakes （P<0.001）. Multiple regression on （dis）similarity matrices analysis （MRM） showed that the heterogeneity of phytoplankton communities among the three lakes was positively affected by NO3--N and pH and negatively affected by dissolved oxygen （DO） and was closely positively correlated with the abundance of six dominant species, namely, S. quadricauda, U. acus, N. stagnorum, Pseudoanabaena sp., Merismopedia punctata, and A. minutissimum. These results indicate that aquatic plants with different growth types could affect the composition, structure, and stability of phytoplankton communities in the same habitat with them by shaping their habitat heterogeneity. Therefore, selecting specific growth types of aquatic plants for aquatic ecosystem restoration in wetland construction and management will be conducive to regulate the state of water habitat and phytoplankton community structure effectively.

Reintroduction by transplanting seedlings from natural regeneration: an alternative for ecological restoration?

Collecting and transplanting wild seedlings and mature plants have been used in restoration projects to reduce costs and increase conservation of local genetic material. We review the published literature on restoration projects that used transplanted seedlings and mature plants for ecological restoration. Searching the Web of Science platform using five keywords for articles published in 1945–2023 resulted in 621 articles, with only 51 (9%) of them relevant to the topic. We categorized these 51 publications by ecosystem type, the number and growth forms of species, plant survival rate, as well as the time and cost of transplantation. Forests and wetlands were the most researched ecosystems, and most articles studied tropical forests and the southeastern region of Brazil. Nearly half of the studies (44%) used trees for transplantation, and 73% focused on only one species. In wetlands, mainly aquatic herbs were transplanted (38%). Survival was highest in wetlands (lakes) and lowest in temperate and tropical forests, regardless of the number of species or growth forms. Only three articles (7%) included costs or the time frame of the process of transplantation or monitoring. Despite having few published studies, this practice has high potential for the ecological restoration of tropical and temperate forests. Seedlings and adult plants from natural regeneration can be transplanted to complement or even replace conventional methods of planting nursery seedlings and direct sowing.

Teaching social work students about evidence-based practice using peer-led learning and assessed conversations

ABSTRACT While the assessment of students on social work placement has attracted a sizable body of research and commentary, on-campus assessments have attracted less attention. With advances in artificial intelligence and the rise of essay-mills, the rigor of assessment by assignment submission is threatened. Acknowledging the need for educators to review assessment in-line with these contemporary challenges and importance of developing skills for practice, this paper presents an evaluation of implementing assessed conversations in a compulsory evidence-based practice module for Bachelor of Social Work students. Replacing group presentations, students agreed with the introduction of assessed conversations to foster authentic collaboration with peers; while assuring students they would receive formative feedback on their performance before being formally assessed. Sixty students took part in nine focus groups offering feedback on their experience of assessed conversations. Students suggested this was a more challenging form of assessment, however, growth and development was reported. Students described a depth of knowledge achieved and greater confidence in evidence-based practice then they had envisaged possible. Findings suggested three possible factors in successfully implementing assessed conversations: Extensive peer support, formative assessed conversations, and learning by doing. Options for the continuation of research on assessed conversations are discussed.

ANALYSING THE POTENTIAL OF CORAL REEF ECOSYSTEMS FOLLOWING THE COVID-19 PANDEMIC IN BONDALEM, BULELENG, BALI

Coastal and marine areas have considerable biological resource potential, because they are supported by three main ecosystems, namely mangrove ecosystems, seagrass beds and coral reefs. Coral reefs are one of the coastal ecosystems that contribute greatly to coastal areas. But behind the great potential, it is also very vulnerable to damage, both caused by nature and human activities on land and in sea waters. As an effort to maintain the existence of these ecosystems, ecosystem monitoring is needed to find out how much potential is still available in the coastal area. The purpose of this study was to determine and provide information related to the potential and condition of coral reefs in Bondalem Village. This research used descriptive quantitative method with purposive sampling technique. The data taken is primary data that includes observations of coral reefs based on the form of growth (lifeform). Coral reef data collection was carried out using the UPT (Underwater Photo Transect, Underwater Photo Transect) method. The results obtained, coral reefs at the observation station have a total of 18 lifeforms. The percentage of coral cover obtained at a depth of 3 meters has a coral cover ranging from 35.34%, while at a depth of 10 meters the result of coral cover is 26.30% (medium category). The coral reef ecosystem uniformity index ranges from 0.96 - 0.97 (high). The diversity index of coral reef ecosystems in Bondalem Village ranged from 1.25 which is included in the relatively medium category (1&lt;H'&lt;3). The dominance index of coral reef ecosystem in Bondalem Village ranged from 0.064 - 0.066 (low).

Chiefdom, Vassalage and Empire: The Political Structures of Arabia from the First CE to the Advent of Islam

No political system could ever evolve in isolation fr om the environment in which it emerged. Similarly, no particular system can be understood as stagnant. It is actually the culmination or an improved form of a long historical growth. Keeping in view this synopsis, Islamic political institutions could be placed in the time and space in which the salient political features and social trends of the Jahiliyah Arabia and the neighboring political cultures contributed to their foundation and evolution. In addition to the compact political structures of Aksum, Rome and Persia, and then Byzantine and Sassanid on the borders, internally the pre-Islamic Arabs had a diverse mechanism for managing their affairs. The Arabian South experienced organized governance as compared to the north and central regions. This diversity can be attributed to the geo-strategic location and ecological environment of the peninsula. The fertile South was more supportive to the growth of a political mechanism than the arid, geopolitically more vulnerable north and central regions. In a nutshell, a proper study of the less discussed Jahiliyah politics could minimize assumptions about the complete lawlessness and political unawareness of the Arabs in politics and governance.