scholarly journals Local Victory: Assessing Interspecific Competition in Seagrass From a Trait-Based Perspective

2021 ◽  
Vol 12 ◽  
Author(s):  
Agustín Moreira-Saporiti ◽  
Sonia Bejarano ◽  
Inés G. Viana ◽  
Elizabeth Fay Belshe ◽  
Matern S. P. Mtolera ◽  
...  
Keyword(s):  
Resource Competition ◽  
Plant Size ◽  
Maximum Length ◽  
Competitive Interactions ◽  
Size Difference ◽  
Seagrass Species ◽  
Thalassia Hemprichii ◽  
Functional Strategy ◽  
Seagrass Meadows ◽  
Halophila Ovalis

Tropical seagrass meadows are formed by an array of seagrass species that share the same space. Species sharing the same plot are competing for resources, namely light and inorganic nutrients, which results in the capacity of some species to preempt space from others. However, the drivers behind seagrass species competition are not completely understood. In this work, we studied the competitive interactions among tropical seagrass species of Unguja Island (Zanzibar, Tanzania) using a trait-based approach. We quantified the abundance of eight seagrass species under different trophic states, and selected nine traits related to light and inorganic nutrient preemption to characterize the functional strategy of the species (leaf maximum length and width, leaves per shoot, leaf mass area, vertical rhizome length, shoots per meter of ramet, rhizome diameter, roots per meter of ramet, and root maximum length). From the seagrass abundance we calculated the probability of space preemption between pairs of seagrass species and for each individual seagrass species under the different trophic states. Species had different probabilities of space preemption, with the climax species Thalassodendron ciliatum, Enhalus acoroides, Thalassia hemprichii, and the opportunistic Cymodocea serrulata having the highest probability of preemption, while the pioneer and opportunistic species Halophila ovalis, Syringodium isoetifolium, Halodule uninervis, and Cymodocea rotundata had the lowest. Traits determining the functional strategy showed that there was a size gradient across species. For two co-occurring seagrass species, probability of preemption was the highest for the larger species, it increased as the size difference between species increased and was unaffected by the trophic state. Competitive interactions among seagrass species were asymmetrical, i.e., negative effects were not reciprocal, and the driver behind space preemption was determined by plant size. Seagrass space preemption is a consequence of resource competition, and the probability of a species to exert preemption can be calculated using a trait-based approach.

scholarly journals Community Structure of Seagrass Meadows In Mantehage Island Waters, North Sulawesi

2014 ◽  
Vol 1 (4) ◽  
pp. 177
Author(s):  
Simon I Patty ◽  
Husen Rifai
Keyword(s):  
Diversity Index ◽  
Seagrass Species ◽  
Thalassia Hemprichii ◽  
Seagrass Meadows ◽  
North Sulawesi ◽  
Halophila Ovalis ◽  
Cymodocea Rotundata ◽  
Syringodium Isoetifolium ◽  
Species Composition And Distribution ◽  
Thalassodendron Ciliatum

Research on the structure of seagrass communities in the waters of the island Mantehage was conducted in September 2010. The purpose of this study is to collect data and information on the structure of seagrass communities. Observations includes the identification seagrass species, measuring the number of individual/stand, cover percentage of each type/species on the transect. 6 types of seagrass found, i.e. Enhalus acoroides, Halophila ovalis, Thalassia hemprichii, Thalassodendron ciliatum, Cymodocea rotundata and Syringodium isoetifolium. Seagrass species composition and distribution varies at each location and is dominated by the presence of Thalassia hemprichii (48.14%) with coverage percentage ranges between 15.91% to 35.11%. Diversity index values ranged from 0.79 to 1.69 ; evenness index between 0.57 to 0.94 and the index of dominance between 0.20 to 0.56. In conclusion, the condition of seagrass meadows in Mantehage island is relatively good and can support marine life adequately.Keywords : Structure communities, seagrass, Mantehage Island

scholarly journals Kondisi dan Keanekaragaman Jenis Lamun di Perairan Pulau Serangan, Provinsi Bali

2018 ◽  
Vol 5 (1) ◽  
pp. 131
Author(s):  
Luh Gede Manik Radzena Martha ◽  
Pande Gde Sasmita Julyantoro ◽  
Alfi Hermawati Waskita Sari
Keyword(s):  
Water Quality ◽  
Diversity Index ◽  
Good Condition ◽  
Quality Parameters ◽  
Seagrass Species ◽  
Thalassia Hemprichii ◽  
Halophila Ovalis ◽  
Cymodocea Rotundata ◽  
Index Value ◽  
Seagrass Coverage

Serangan Island is one of the tourism destinations in Bali which is administratively belong to the municipality of Denpasar. Tourism development near with the segrass habitat cause the segrass ecosystem being degraded in the waters of Serangan Island. This study was aimed to determine the diversity and conditions of seagrass species which were observed from the density and percentage of seagrass coverage and to examine the effect of water quality on the percentage of seagrass coverage. This research was conducted from February to March 2017 on Serangan Island using quantitative descriptive method. Sampling was conducted at three stations by taking data and samples of seagrass, measuring water quality (temperature, salinity, pH, turbidity, substrate observation) and analyze of nitrates and phosphates content. Seven types of seagrass species were found i.e. Enhalus acoroides, Thalassia hemprichii, Cymodocea rotundata, Halophila ovalis, Halodule pinifolia, Syringodium isoetifolium, and Thalassodendron ciliatum. The study showed that the diversity index value was in the medium category. The density of seagrass was classified as very tight (condition scale of 5). The highest density was found on Cymodocea rotundata spesies at station I about 777 ind/m2. The highest percentage of seagrass coverage (79,55%) was found in station I which classified as good condition, while station II and station III were classified as damaged condition with value 13.65% and 20,79% respectively. Finally, the water quality parameters have relatively low effect to seagrass coverage percentage.

Mapping seagrass cost-effectively in the Coral Triangle: Sabah, Malaysia as a case study

2015 ◽  
Vol 21 (2) ◽  
pp. 113 ◽  
Author(s):  
Leela Rajamani ◽  
Helene Marsh
Keyword(s):  
Cost Effective ◽  
Human Populations ◽  
Coral Triangle ◽  
Thalassia Hemprichii ◽  
Seagrass Meadows ◽  
Green Turtles ◽  
Halophila Ovalis ◽  
Seagrass Mapping ◽  
Cymodocea Rotundata ◽  
Syringodium Isoetifolium

Knowledge of the distribution and relative abundance of seagrass communities in the Coral Triangle is limited, despite their global significance and the vital ecosystem services they perform for local human populations, threatened species such as dugongs and green turtles, as well as the role of being a globally significant carbon stock. To address this gap and investigate cost-effective methods in data-poor regions, we conducted seagrass mapping near two islands off the coast of Sabah in Malaysia: Banggi Island (7°15′N, 117°12′E) and Mantanani Island (6°43′N, 116°21′E). We used a staged approach that included: (1) interview surveys, (2) manta tow and spot surveys, and (3) comprehensive transect surveys. Approximately 415 ha and 112 ha of seagrass meadows were mapped off Banggi Island and Mantanani Island respectively. We found 10 species of seagrasses from two families: Halophila ovalis, Halodule uninervis (broad and thin leaf varieties), Thalassia hemprichii, Cymodocea rotundata, Halophila decipiens, Halophila spinulosa, Cymodocea serrulata, Syringodium isoetifolium, Enhalus acoroides and Halophila sp. nov. Our methodology proved cost-effective and the resultant information should be relevant to conservation planners.

scholarly journals Community structure and condition of seagrass meadows in Ayau Islands, Raja Ampat Regency

2020 ◽  
Vol 45 (1) ◽  
pp. 13-24
Author(s):  
Andri Irawan ◽  
Muhammad Hafizt ◽  
Udhi Eko Hernawan
Keyword(s):  
Community Structure ◽  
Environmental Parameters ◽  
Water Clarity ◽  
Well Being ◽  
Common Species ◽  
Thalassia Hemprichii ◽  
Seagrass Meadows ◽  
Halophila Ovalis ◽  
Seagrass Cover ◽  
Baseline Information

Seagrass meadows are an important component of coastal ecosystems, providing many ecosystem services beneficial for human well-being. Basic information about seagrass meadows in Indonesia is relatively limited, particularly in the eastern part of Indonesia, such as the remote Ayau Islands in Raja Ampat. In this paper, we reported the community structure and condition of seagrass meadows in Ayau Islands surveyed during Nusa Manggala Expedition in November 2018. We conducted the seagrass survey using quadrat transect method at five locations, i.e. Reni, Rutum, Abidon, Kanober, and Dorehkar. In the survey, we assessed parameters of community structure, including habitat extent, species composition, seagrass cover, seagrass density, macroalgae and epiphyte cover. We also recorded environmental parameters, i.e. substrate types, water clarity, salinity, water temperature, and nutrient (phosphate and nitrate). Our study showed that seagrass meadows in Ayau Islands are multispecies meadows, composed of two to five species. In overall, five species recorded in Ayau Islands are Cymodocea rotundata, Enhalus acoroides, Halodule pinifolia, Halophila ovalis, and Thalassia hemprichii. The most common species is T. hemprichii as it can be found in all locations. Meadows in Reni, Rutum, and Dorehkar are in a healthy condition, while in Abidon and Kanober are in less healthy condition. This information is of significance as baseline information needed for seagrass conservation planning.

scholarly journals The Inventory of Seagrasses in Marine Field Station of Faculty of Fisheries and Marine Science in Subdistrict of East Likupang District North Minahasa

2018 ◽  
Vol 6 (2) ◽  
pp. 38
Author(s):  
Stevani Rawung ◽  
Ferdinand F Tilaar ◽  
Ari B Rondonuwu
Keyword(s):  
Seagrass Species ◽  
Thalassia Hemprichii ◽  
Field Station ◽  
Enhalus Acoroides ◽  
Halophila Ovalis ◽  
Halodule Uninervis ◽  
Cymodocea Rotundata ◽  
Syringodium Isoetifolium ◽  
Random Survey ◽  
Cymodocea Serrulata

This study was conducted in Marine Field Station of Faculty of Fisheries and Science of Sam Ratulangi University, Sub-district of East Likupang, North Minahasa. This study aims to identified the seagrasses in the water of Marine Field Station. The benefits of this study are for the database of seagrasses ecosystem management and comparative for other studies. The Observation and data collection was using random survey technic by analyzed the areas to collecting all the seagrass species found. Furthermore, the seagrass samples were categorised into each species. The result showed the amount of seagrass species in Marine Field Station are 8 species from 6 genera and 2 families: Cymodocea rotundata, Cymodocea serrulata, Halodule uninervis, Syringodium isoetifolium, Thalassia hemprichii, Enhalus acoroides,  Halophila ovalis, dan Halophila minor.Keyword: Inventory, Seagrass, Marine Field Station ABSTRAKPenelitian dilakukan di perairan Marine Field Station Fakultas Perikanan dan Ilmu Kelautan Unsrat Kecamatan Likupang Timur Kabupatan Minahasa  Utara. Tujuan penelitian  untuk mengidentifikasi lamun yang ada di Perairan Marine Field station. Manfaat penelitian dapat menjadi data pengelolaan ekosistem padang lamun dan dapat menjadi perbandingan untuk penelitian-penelitian selanjutnya. Pengamatan dan pengambilan sampel menggunakan teknik survei jelajah, yaitu dengan menjelajahi wilayah pengamatan sambil mencari semua spesies lamun. Lamun yang diambil adalah semua jenis yang ditemui. Selanjutnya, sampel lamun dikelompokan berdasarkan spesies. Hasil pengamatan menunjukkan jumlah spesies lamun pada lokasi penelitian di Perairan Marine Field Station adalah 8 spesies dari 6 genera dan 2 famili yaitu, Cymodocea rotundata, Cymodocea serrulata, Halodule uninervis, Syringodium isoetifolium, Thalassia hemprichii, Enhalus acoroides,  Halophila ovalis, dan Halophila minor. Kata kunci: Inventarisasi, Lamun, Marine Field Station

scholarly journals KAJIAN KOMUNITAS EKOSISTEM LAMUN DI SEMENANJUNG TARABITAN KECAMATAN LIKUPANG BARAT KABUPATEN MINAHASA UTARA

2021 ◽  
Vol 9 (2) ◽  
pp. 24
Author(s):  
Risandi D Sitaba ◽  
Carolus P Paruntu ◽  
Billy Theodorus Wagey
Keyword(s):  
Species Composition ◽  
Percent Cover ◽  
Seagrass Beds ◽  
Seagrass Species ◽  
Thalassia Hemprichii ◽  
Enhalus Acoroides ◽  
Halophila Ovalis ◽  
Halodule Uninervis ◽  
Cymodocea Rotundata ◽  
Syringodium Isoetifolium

This research was conducted in the waters of Tarabitan Peninsula, West Likupang North Minahasa using quadants transect method. The purpose of this study was to determine the community structure of seagrass found in that waters as initial information for sustainable management seagrass ecosystem . Field observation was conducted to identify the seagrass species, number of individuals/shoots, percent cover for each type of seagrass in those plotting quadrants. The result of this study documented 6 types of seagrass namely, Enhalus acoroides, Thalassia hemprichii, Cymodocea rotundata, Syringodium isoetifolium, Halophila ovalis and Halodule uninervis. The species composition and distribution of seagrass were varied and was dominated by Thalassia hemprichii was the most dominant seagrass species with a relative density of 55.55%, a relative frequency of 33.67%, 39.92% relative cover, an important value index of 129.03%, a diversity index of 1.30 belonging to this condition, moderate, the uniformity index of 0.72 is classified as high and the dominance index of 0.2 is classified as low. Based on Minister of Environment Decree Republic Indonesia No. 200 of 2004 concerning the status of seagrass beds, the condition of the seagrass beds in the waters of Tarabitan Village is classified as rich / healthy with a cover value of ≥ 60. Keywords : Seagrass Community, Species Composition,  distribution, Tarabitan Peninsula           Penelitian ini dilakukan di perairan Semenanjung Tarabitan Likupang Barat Minahasa Utara dengan menggunakan metode transek kuadran. Tujuan penelitian ini adalah untuk mengetahui struktur komunitas lamun yang terdapat di perairan tersebut sebagai informasi awal untuk pengelolaan lamun secara berkelanjutan. Pengamatan lapangan dilakukan untuk mengidentifikasi jenis lamun, jumlah individu/tegakan, persentase tutupan tiap jenis lamun pada tiap kuadran. Hasil penelitian ini mendokumentasikan 6 jenis lamun yaitu Enhalus acoroides, Thalassia hemprichii, Cymodocea rotundata, Syringodium isoetifolium, Halophila ovalis dan Halodule uninervis. Komposisi jenis dan sebaran lamun bervariasi dan didominasi oleh jenis lamun Thalassia hemprichii merupakan jenis lamun yang paling dominan dengan kerapatan relatif 55,55%, frekuensi relatif 33,67%, tutupan relatif 39,92%, indeks nilai penting 129,03%, indeks keanekaragaman 1,30 tergolong dalam kondisi sedang, indeks keseragaman 0,72 tergolong tinggi dan indeks dominansi 0,2 tergolong rendah. Berdasarkan Keputusan Menteri Lingkungan Hidup Nomor 200 Tahun 2004, kondisi padang lamun di perairan Desa Tarabitan tergolong kaya / sehat dengan nilai tutupan ≥ 60.Kata Kunci: Komunitas Lamun, Komposisi Jenis, Distribusi, Semenanjung Tarabitan

DENSITY AND THE COVERAGE OF SEAGRASS ECOSYSTEM IN BAHOI VILLAGE COASTAL WATERS, NOTRH SULAWESI

2017 ◽  
Vol 9 (1) ◽  
pp. 375-383 ◽  
Author(s):  
Muh. Fahruddin ◽  
Fredinan Yulianda ◽  
Isdradjad Setyobudiandi
Keyword(s):  
Coastal Waters ◽  
Seagrass Species ◽  
Reef Habitat ◽  
Thalassia Hemprichii ◽  
Halophila Ovalis ◽  
Seagrass Ecosystem ◽  
Seagrass Cover ◽  
Cymodocea Rotundata ◽  
Syringodium Isoetifolium ◽  
Coral Reef Habitat

Physical seagrass ecosystem damage have been reported in various regions in Indonesia. Seagrass ecosystem damage is caused by human activity such as trampling seagrass and boats that muddy the waters and reduced the density and seagrass cover. This study aims to provide information about the density and the coverage of seagrass. The method used in this research is the transect method measuring 50x50 cm squared at three different locations by considering coastal ecosystems Bahoi village that already exist. Station 1 is near to mangrove habitat, station 2 is right on seagrass habitats, and station 3 is near to coral reef habitat. The results indicated there is six seagrass species that found in the Bahoi village which is Enhalus acoroides, Thalassia hemprichii, Cymodocea rotundata, Syringodium isoetifolium, Halophila ovalis, and Halodule uninervis. The density and seagrass cover is shows that the station 1 has the highest density and seagrass cover percentage compared with the other stations. The highest density of seagrass species located in station 1 with 955 individuals/m2, and the lowest was located at station 3 with 699 individuals/m2. While the highest cover percentage is located at station 1 with 270% and the lowest located at station 3 with 229%. Keyword: seagrass ecosystem, density, coverage, Bahoi

scholarly journals Biomass explains the intensity of facilitative – not competitive – interactions: three intraspecific tests with annuals

Web Ecology ◽  
2012 ◽  
Vol 12 (1) ◽  
pp. 49-55 ◽  
Author(s):  
C. Ariza ◽  
K. Tielbörger
Keyword(s):  
Size Dependence ◽  
Resource Competition ◽  
Theoretical Models ◽  
Plant Size ◽  
Competitive Interactions ◽  
Positive Interactions ◽  
Plant Interactions ◽  
Belowground Competition ◽  
Size Dependent ◽  
Negative Effect

Abstract. Despite efforts to discern the role of plant size in resource competition, the circumstances under which size-dependent plant-plant interactions occur are still unclear. The traditional assumption is that competition intensifies with increasing neighbour size. However, recent studies suggest that the size (biomass) dependence of competitive interactions is strongest at very low biomass levels and becomes negligible after a certain threshold neighbour biomass has been reached. We searched for the generality of such patterns for three common annual plant species in Israel. We monitored target and neighbour biomass along their entire lifecycle using an even-aged, intraspecific and intrapopulation competition screenhouse experiment under water-limited conditions. For all focal species, neighbour presence had a net negative effect on vegetative biomass at harvest. However, this was not explained by increasing neighbour biomass over time, as a consistent pattern of size-dependent facilitative, rather than competitive, interactions was observed at all life stages. We explain these observations in terms of co-occurring aboveground facilitation and dominant belowground competition for water. Since our findings are the first of their kind and contradict theoretical predictions of biomass dependence of net negative interactions, we advocate further experiments addressing size dependence in interactions among plants. In particular, theoretical models addressing size dependence of positive interactions must be developed.

Do the abundance, diversity, and community structure of sediment meiofauna differ among seagrass species?

2015 ◽  
pp. 1-11
Author(s):  
Jian-Xiang Liao ◽  
Hsin-Ming Yeh ◽  
Hin-Kiu Mok
Keyword(s):  
Ecosystem Engineer ◽  
Structural Complexity ◽  
Nematode Species ◽  
Small Scale ◽  
Seagrass Species ◽  
Thalassia Hemprichii ◽  
Halophila Ovalis ◽  
Deposit Feeders ◽  
Benthic Environment ◽  
Abundance And Diversity

The structural complexity of macrophytes that provide various microhabitats is related to local infaunal abundance and diversity. Seagrass is considered an ecosystem engineer that alters the benthic environment and enables certain distinct meiofauna to thrive in sediments. The effects of seagrass species in a mixed-species seagrass bed at Haikou, Taiwan were examined. Analysing quantitative samples obtained from patches ofThalassia hemprichii, Halodule uninervis, Halophila ovalisand adjacent unvegetated sediments inspected the community structures of meiofauna and marine nematodes. The abundance and diversity of crustaceans and nematodes were substantially higher in habitats in which seagrass grew than in those comprising unvegetated sediments. Both the compositions of higher meiofaunal taxa and nematode species were distinct between seagrass habitats and unvegetated areas. Several nematode species existed exclusively in patches of individual seagrass species, whereas no nematode specifically occurred in unvegetated areas. Regarding the trophic types of nematodes, non-selective deposit feeders were prevalent in the present study, whereas selective deposit feeders and epistrate feeders were relatively dominant in seagrass habitats. Sediments underneath various patches of seagrass species harbour dissimilar nematode communities, even with similar sediment parameters and at a small-scale distance.

Distribution of seagrasses and associated juvenile commercial penaeid prawns in north-eastern Queensland waters

1987 ◽  
Vol 38 (1) ◽  
pp. 103 ◽  
Author(s):  
RG Coles ◽  
WJ Lee Long ◽  
BA Squire ◽  
LC Squire ◽  
JM Bibby
Keyword(s):  
Summer Rainfall ◽  
Dry Weight ◽  
Seagrass Beds ◽  
Seagrass Species ◽  
Thalassia Hemprichii ◽  
Halophila Ovalis ◽  
Penaeid Prawn ◽  
Seagrass Biomass ◽  
Almost All ◽  
The Tropics

Thirteen species of seagrass and six species of juvenile penaeid prawn of commercial importance were found in seagrass beds in waters between Cape York and Cairns. The pioneering seagrass species, Halodule uninemis (Forsk.) Aschers, and Halophila ovalis (R. Br.) Hook. f., were present in almost all coastal areas. Two seagrass species often dominant in the tropics, Enhalus acoroides (L.f.) Royle and Thalassia hemprichii (Ehrenb.) Aschers., were uncommon. This is likely to have resulted from environmental stress during periods of reduced salinity and high turbidity associated with seasonal summer rainfall. Halophila decipiens Ostenfeld was the only species found in depths > 11 m. Three depth-related zones of species are described. With the exception of E. aroroides, most seagrasses were <20 cm in height. Seagrass biomass was greatest in 2-6 m of water. Maximum dry weight of above-ground plant material and maximum leaf area from a square metre of bottom was 99.6 g and 4.5 m2, respectively, at the Flinders Group of islands. The distribution of prawns and seagrasses did not show a trend with latitude. Penaeus esculentus Haswell and Metapenaeus endeavouri (Schmitt), the most numerous penaeid prawn species in commercial trawl catches, were also the most numerous juvenile prawns in seagrass beds. Juvenile P. longistylus Kubo were found for the first time in northern Queensland seagrass beds. Although juveniles of this species appeared to occupy only a narrow habitat range, these habitats were found in coastal bays, in estuaries and on coral-reef platforms where conditions were suitable. Size-class data suggest that reef prawns and coastal prawns are parts of the same population. The timing of the life cycle of the major commercial prawn species differed from that found previously in the Gulf of Carpentaria.

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