A trophic diversity index for presence-absence food data

Oecologia ◽  
1976 ◽  
Vol 25 (2) ◽  
pp. 187-191 ◽  
Author(s):  
Carlos M. Herrera
1980 ◽  
Vol 7 (3) ◽  
pp. 365 ◽  
Author(s):  
S Hall

An analysis of faecal samples and stomach contents of Antechinus stuartii and A. swainsonii inhabiting forest in southern Victoria revealed a large overlap in the type and size of prey items taken by these dasyurids. The frequencies of 23 prey types and 15 prey sizes in the diets of these predators were both positively correlated. Weevils (Coleoptera, Curculionidae) represented the only difference in prey types not attributed to individual variations. A. stuartii took more, and a wider size range of, weevils than did A. swainsonii; the trophic diversity index of prey types was greater for A. stuartii. The larger A. swainsonii took more prey greater than 20 mm; it took prey on the average 23% longer and 75% heavier than did A. stuartii; the trophic diversity index of prey size was greater for A. swainsonii. It is concluded that these morphologically distinct predators are exploiting the same large population of prey. They are both generalists and appear to be opportunistic feeders.


2009 ◽  
Vol 46 (3) ◽  
pp. 183-189 ◽  
Author(s):  
V. Tomar ◽  
W. Ahmad

AbstractFunctional diversity and detritus soil food web of soil inhabiting nematodes in natural woodland dominated by Acacia nilotica L. was studied. Functional diversity was studied in terms of trophic groups assessed by Trophic diversity index (TDI) and Shannon-Weaver index (H′), while food web was diagnosed by channel index (CI). The plant parasitic channel was determined by plant parasitic index (PPI). The stability of the soil ecosystem was measured in terms of maturity index (MI), structure index (SI) and enrichment index (EI). Shannon-Weaver index of the area was recorded as 2.1 ± 0.3 while trophic diversity index 2.6 ± 0.7, maturity index (MI) 3.1 ± 0.2, channel index 62.4 ± 28.1 and structure and enrichment indices 68.1 ± 18.5 and 15.4 ± 13.7 respectively. A high degree of positive correlation was recorded between population of dorylaims and MI while some degree of negative correlation existed between population of plant parasitic nematodes and MI. Population of other nematodes showed a positive correlation with SI and EI. The faunal profile was found to be tilted towards quadrat C giving the idea of relatively undisturbed ecosystem with moderate enrichment and fungal decomposition channel.


2021 ◽  
Author(s):  
Jorge Lozano ◽  
Marta Guntiñas ◽  
Rodrigo Cisneros ◽  
Esther Llorente ◽  
Aurelio F. Malo

ABSTRACTHere we describe the dietary patterns of the culpeo (or Andean fox) at a biogeographical scale. We also analyze the influence of exotic lagomorphs on its diet and explore differences between culpeo subspecies. We selected 17 mutually comparable diet studies, which include 19 independent diet assessments. Then, we extracted and standardized the values of the different diet components from these studies and calculated the relative frequency of occurrence (RF) of the ten main trophic groups that we found. Further, we calculated the Shannon-Wienner H’ trophic diversity index.The results showed that small mammals (41%), lagomorphs (21%), invertebrates (12.4%) and large herbivores (7.3%) were the most consumed groups. A factorial analysis of all trophic groups rendered four orthogonal factors that were used as response variables in relation to a set of environmental predictors. Altitude correlated with most factors (i.e. trophic groups). Exotic lagomorphs were consumed in lowlands, in higher latitudes and in regions showing high values of the human footprint index, replacing in these areas native fauna as the main prey. There were no differences in diet between the two main culpeo subspecies analysed, L.c. culpaeus and L.c. andinus.Finally, the best explanatory models (GLM) of trophic diversity selected, using the Akaike’s information criterion (AIC), showed that the most diverse diets were those composed of large herbivores, edentates, carnivorous species, birds and herptiles (i.e. amphibians and reptils), in areas of high rainfall located in protected areas. Neither latitude nor altitude seemed to have an effect on the trophic diversity of the culpeos, as they were not retained by the final models.


2019 ◽  
Vol 4 (2) ◽  
Author(s):  
Zulkifli Aiyub Kadir ◽  
Bahagia Bahagia

<p>Humans have utilized landscape for  produces a diverse character of the wider area of the watershed. Agroforestry is a land management system in addressing the problems that arise due to changes in land use of soil and water conservation. The aim of the study was to analyze plant diversity in agroforestry practices that have services in the Krueng watershed landscape in Aceh watershed. Develop strategies in the Krueng Aceh DAS agroforestry service. This research was conducted in the upper, middle and downstream of the Krueng Aceh watershed, with a rapid method of Agro-Biodiversity Appraisal and SWOT. The results showed that the composition of the vegetation structure found in the study sites tended to vary with the diversity index of agroforestry that was currently in the upstream and middle of the Krueng Aceh watershed. Based on SWOT analysis, internal scores are 2.45 and external scores are 3.21. Agroforestry practices in the upper stream of Krueng Aceh watershed were dominated by <em>Aleurites moluccana</em>, <em>Areca cathecu</em>, and  <em>Averrhoa bilimbi</em> L  species with the highest INP in the upper stream of Krueng Aceh watershed. Vegetation at the middle stream of Krueng Aceh watershed dominated by <em>Areca cathecu,</em> <em>Lansium domesticum</em> and Musa<em> paradisiaca</em>.  </p>


SIMBIOSA ◽  
2014 ◽  
Vol 3 (2) ◽  
Author(s):  
Notowinarto Notowinarto ◽  
Ramses Ramses ◽  
Mulhairi Mulhairi

Bulang districts Batam Islands of  Riau province (Riau Islands), its consists of many islands with as well as having the potential diversity of coastal marine life in particular kinds of macro algae or seaweed. Conducted research aimed to determine the structure of macro- algal communities in the intertidal zone islands. The results of the identification of algal species found 16 species are: the Order of Chlorophyceae as 6 spesies; Order Phaeophyceae as 2 spesies; and Order Rhodophyceae as 8 spesies. The community structure at the five stations showed the highest values were found in the island of dominance Cicir (D ' = 0.79) , uniformity index values on Tengah Island (E ' = 0.99) , while the island Balak had the highest diversity index (H ' = 0.88) , with the abundance patterns of population structure on the island is pretty good Central . Results of correlation analysis of regression between IVI types of algae with the conditions of environmental quality suggests that there is a significance (Fhit ˃ F table and the value of r = > 90 %) between IVI algae Halimeda sp and Cryptarachne polyglandulosa at each station with a temperature parameter surface (⁰C) , depth temperature (⁰C) and pH values. Keywords : Algae, Community Structure, Important Value Index.


2018 ◽  
Vol 8 (2) ◽  
pp. 348-353
Author(s):  
E. A. Kuchina ◽  
N. D. Ovcharenko ◽  
L. D. Vasileva

<p>Anthropogenic impact on the population of ground beetles leads to a change in their numbers, structure of dominance, density, species composition, spectrum of life forms. This makes the beetles Carabidae a convenient and informative bioindicator of the ecological state of biocenoses. The material for this work was the Carabidae collections conducted in June-August 2016-2017 in the park zone of different regions of Barnaul, differing in location, area, hydrological regime, vegetation cover, purpose and anthropogenic load. When processing the material, the quantitative, species and generic composition of the carabidae was determined, calculations were made for such indicators as the Berger-Parker dominance index, the Shannon species diversity index (Hs), and the Jacquard species similarity index. The fauna (Coleoptera, Carabidae) of the park zone of Barnaul is represented by 55 species belonging to 20 genera. The dominant group is represented by species belonging to steppe, forest and polyzonal groups. Forest-steppe species of ground beetles as dominants have not been identified in any of the investigated territories. The greatest variety of ecological groups was noted on the territory of the Yubileyny рark, which is explained by the presence of zones with various microclimatic conditions, the presence of a birch grove that flows through the park with the Pivovarka River, and a wide log in the park. Registered species belong to eight groups of life forms belonging to two classes - zoophagous and myxophytophagous. On the numerical and species abundance, zoophages predominate. The spectrum of life forms corresponds to the zonal spectrum characteristic of the forest-steppe zone.</p><p> </p>


Author(s):  
M. A. Gondal ◽  
S. Iqbal ◽  
U. Atique ◽  
N. U. Saher ◽  
N. A. Qureshi ◽  
...  

Abstract The primary objective of this study was to investigate the seasonal fish and crustacean variations concerning taxonomic composition, species richness, and diversity in sandy beach habitat. For this purpose, we investigated the Sonmiani Hor lagoon area during four distinct seasons, i.e., northeast (NE) monsoon, pre-monsoon, south-west (SW) monsoon, and post-monsoon for one year. During each haul, the net was pulled about 100m along the beach in 0.5m depth. The results showed a strong linear correlation between the diversity index and equitability in fishes (r = 0.978). The diversity index was strong negatively correlated with the abundance and biomass (r = -0.978, -0.972, respectively). The physical attributes like sea surface water temperature and salinity showed a strong negative effect on species assemblages (r = -0.981 and -0.943, respectively). The mean air and water temperature illustrated approximately 3°C difference during NE and pre-monsoon seasons. However, salinity, pH, and electrical conductivity did not show any significant seasonal variabilities. Under the ecological indices, the fish species displayed higher diversity (H’ = 3.19) during SW monsoon, whereas the lowest diversity was observed during pre-monsoon (H’ = 1.58). The equitability and species richness, however, remained more noticeable during SW monsoon (J’ = 0.81). The total number of individuals of fish and crustaceans reached 4799 with 3813 fish individuals and 986 individuals of crustaceans. A total of 27 families of fish while five crustacean families comprising of 30 genera and 38 fish species while ten genera and 17 species of crustaceans were recorded. Liza subviridis displayed the highest abundance among the sampled fish species. In conclusion, fish species constituted a significant part of the coastal fauna in the study area. The seasonal variations displayed distinct variations in fish species composition and diversity.


2020 ◽  
Vol 14 (1) ◽  
pp. 34
Author(s):  
Faezah Pardi

This study was conducted at Pulau Jerejak, Penang to determine the floristic variation of its tree communities. A 0.5-hectare study plot was established and divided into 11 subplots. A total of 587 trees with diameter at breast height (DBH) of 5 cm and above were measured, identified and recorded. The tree communities comprised of 84 species, 63 genera and 32 families. The Myrtaceae was the most speciose family with 10 recorded species while Syzgium glaucum (Myrtaceae) was the most frequent species. The Myrtaceae recorded the highest density of 306 individuals while Syzgium glaucum (Myrtaceae) had the highest species density of 182 individuals. Total tree basal area (BA) was 21.47 m2/ha and family with the highest BA was Myrtaceae with 5.81 m2/ha while at species level, Syzgium glaucum (Myrtaceae) was the species with the highest total BA in the plot with value of 4.95 m2/ha. The Shannon˗Weiner Diversity Index of tree communities showed a value of 3.60 (H'max = 4.43) and Evenness Index of 0.81 which indicates high uniformity of tree species. The Margalef Richness Index (R') revealed that the tree species richness was 13.02. Myrtaceae had the highest Importance Value of 20.4%. The Canonical Correspondence Analysis (CCA) showed that Diospyros buxifolia (Ebenaceae) and Pouteria malaccensis (Sapotaceae) were strongly correlated to low pH. Dysoxylum cauliflorum (Meliaceae) and Eriobotrya bengalensis (Rosaceae) were correlated to phosphorus (P) and calcium ion (Ca2+), respectively. Therefore, the trees species composition at Pulau Jerejak showed that the biodiversity is high and conservation action should be implemented to protect endangered tree species. Keywords: Floristic variation; Tree communities; Trees composition; Pulau Jerejak; Species diversity


2017 ◽  
Vol 14 (2) ◽  
pp. 1 ◽  
Author(s):  
Noor Nasuha Abd Aziz ◽  
Siti Khairiyah Mohd Hatta ◽  
Idris Abd Ghani ◽  
Saiyid Jalaluddin Saiyid Shaifuddin

A study on abundance and diversity of Hymenoptera was conducted in Gunung Datuk, Rembau. Samplings were conducted from November 2014 to February 2015 using six Malaise traps. Three traps were placed at Site 1 at 700m height for high elevation and the remaining traps were placed at Site 2 at 200m height for low elevation. A total number of 221 Hymenopteran were collected which consist of nine families namely Ichneumonidae, Formicidae, Braconidae, Bethylidae, Evaniidae, Tiphiidae, Vespidae, Pompilidae and Apidae. In this study, 93 individuals were obtained from Site 1, comprising nine families and 43 morphospecies while 127 individuals were obtained from Site 2 with nine families and 45 morphospecies. Formicidae was the most dominant family collected from both sites with a total of 104 individuals while the least family recorded was Apidae with only one individual. Shannon’s Weiner Diversity Index (H’) showed Site 1 had the higher diversity value with H’ = 3.17 compared to Site 2 with value H’ = 3.12. For Evenness Index, Site 1 had higher value compared to Site 2 with E’ = 0.84 and E’ = 0.82 respectively. Moreover, for Margalef Richness Index, Site 1 recorded R’ = 9.24 while site two recorded R’ = 9.08 which concluded that Site 1 had higher species richness compared to Site 2. Paired t-test showed that both sites had no significant difference with p>0.05. Overall study showed that the diversity and abundance of Hymenoptera in Gunung Datuk were low since the value of H’ is less than 3.50.


Author(s):  
Ngo Xuan Nam

The zoobenthos samples were collected in 30 collecting sections from 02nd to 13th June and from 02nd to 13th October 2014. Investigation of species compositon of zoobenthos in coastal areas, Thai Binh province was identified 72 species belonging to 56 genera of 33 families, 14 orders, 4 classes (Gastropoda, Bivalvia, Crustacea, Polychaeta), 3 phyla (Mollusca, Arthropoda, Annelida). In particular, Mollusca was by far the most popular with 46 species, accounting for roughly 63.8%, compared to the figure of Arthropoda was 23 species, occupying approximately 31.9%, Annelida was 3 species, occupying approximately 4.3%. The density of zoobenthos at the sampling sites averaged from 17 to 420 individuals/m2. The Shannon-Weiner (H') diversity index at the study sites averaged from 2.13 to 3.63.


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