How important are species richness, species evenness and interspecific differences to productivity? A mathematical model

Oikos ◽  
2000 ◽  
Vol 88 (1) ◽  
pp. 57-66 ◽  
Author(s):  
Ivan Nijs ◽  
Jacques Roy
Keyword(s):  
Mathematical Model ◽  
Species Richness ◽  
Species Evenness ◽  
Interspecific Differences

The Ecological Balance of Nature: Identifying Stasis and Growth in Late Cretaceous Planktonic Foraminifera from ODP Hole 690C (Weddell Sea)

2020 ◽  
Vol 50 (3) ◽  
pp. 313-317
Author(s):  
Martin A. Buzas ◽  
Lee-Ann C. Hayek ◽  
Brian T. Huber
Keyword(s):  
Species Richness ◽  
Late Cretaceous ◽  
Planktonic Foraminifera ◽  
Sampling Time ◽  
Weddell Sea ◽  
Species Evenness ◽  
Data Set ◽  
Balance Of Nature ◽  
Ecological Balance ◽  
Do So

ABSTRACT The ecological balance of nature is defined as an equilibrium between species richness (S) and species evenness (E) such that diversity (H) remains constant with time. Based on this definition, our approach identifies growth or decline in communities as perturbations from stasis and has successfully done so for benthic foraminiferal communities. Here, we examine whether this approach is appropriate for planktonic foraminifera. To do so, we utilized planktonic foraminiferal counts (39 samples, 66% recovery) from Maastrichtian sediments in the Weddell Sea from ODP Hole 690C. A total of 24 species were observed and both >63-µm and >150-µm fractions were counted. In the >63-µm fraction, nine communities were recognized while in the >150-µm fraction, there were 12. In both fractions at 70.45 Ma, a boundary was recognized and immediately after this boundary, a community in growth was identified. A trend of increasing diversity upcore was substantiated by regression on individual samples. For our purposes, the >150-µm fraction in this data set is sufficient to recognize community trends. The >150-µm fraction in Hole 690C has 82% of the sampling time in stasis and an average time per community is 0.85 Ma. The >63-µm fraction has 73% of the sampling time in stasis and an average time per community of 1.02 Ma.

scholarly journals Diversity of Hoverfly (Diptera: Syrphidae) Communities in Different Habitat Types in Zanjan Province, Iran

ISRN Zoology ◽  
2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Masumeh Naderloo ◽  
Shahrokh Pashaei Rad
Keyword(s):  
Species Richness ◽  
Species Diversity ◽  
Rice Field ◽  
Diversity Analysis ◽  
Species Evenness ◽  
Habitat Types

The diversity of hoverfly communities was studied in four different habitat types (river side, woodland, fruit garden, and rice field) in the years of 2008 and 2009. Adult hoverflies were collected from different habitants in Zanjan province. A total of 31 species with 750 individuals of hoverflies were collected, among which Sphaerophoria scripta (Linnaeus), Eristalis arbustorum (Linnaeus) and Eristalis tenax (Linnaeus) were found to be the most abundant. Records from these four sites were used in the diversity analysis. The results indicated that river side and rice field showed the highest and lowest degree of species richness and species diversity. Also, river side and rice field showed the highest and lowest species evenness, respectively.

scholarly journals STRUKTUR KOMUNITAS IKAN TARGET DI TERUMBU KARANG PULAU HOGOW DAN PUTUS-PUTUS SULAWESI UTARA

2011 ◽  
Vol 7 (2) ◽  
pp. 60 ◽  
Author(s):  
Unstain NWJ Rembet ◽  
Mennofatria Boer ◽  
Dietriech G Bengen ◽  
Achmad Fahrudin
Keyword(s):  
Multivariate Analysis ◽  
Species Richness ◽  
Coral Reef ◽  
Species Diversity ◽  
Species Abundance ◽  
Controlling Factors ◽  
Ecological Groups ◽  
Species Evenness ◽  
Target Fish ◽  
Abundance And Diversity

ABSTRACTCommunity structure of target fishes was analyzed to understand their response to different conditions of coral reefs in several places of Hugow and Putus-Putus islands. This study focused on species abundance and diversity including Shannon-Wiener’s species diversity (H’), species richness (SR), species evenness (J’) and dominance (d) indices, respectively. A multivariate analysis was used for the classification or correspondence factorial analyses. The result recorded 4,501 individuals belonging to 52 species of target fishes. Both cluster and correspondence analyses clearly recognized 3 groups of target fish with 2 major controlling factors for the development of these 3 ecological groups, i.e. coral reef conditions and geographic position to the hydrodynamic condition.ABSTRAKStruktur komunitas ikan target dianalisis untuk melihat respon ikan target terhadap perbedaan kondisi terumbu karang di beberapa lokasi Pulau Hogow dan Putus-Putus. Penelitian ini dilakukan pada bulan Oktober 2010 dengan pengambilan data di 6 stasiun. Dalam penelitian ini telah dikaji variabel komunitas seperti kelimpahan dan keanekaragaman spesies termasuk indeks keanekaragaman spesies Shannon-Wiener (H’), indeks kekayaan spesies (SR), indeks kemerataan spesies (J’) dan indeks dominasi (d). Untuk melihat assemblage ikan target dilakukan analisis multivariat baik analisis klasifikasi maupun analisis faktorial koresponden. Dalam penelitian ini diperoleh 4501 indidu yang termasuk dalam 52 spesies ikan target. Analisis multivariat baik analisis cluster maupun analisis koresponden telah memisahkan dengan jelas 3 grup ikan target, dimana terdapat dua faktor utama pengendali pembentukan 3 grup ekologis ini yakni faktor kondisi terumbu karang dan faktor posisi lokasi terhadap kondisi hidrodinamika perairan.

scholarly journals Avian Diversity of Oak Mixed Forest in Pauri Garhwal, Uttarakhand, India

2021 ◽  
Vol 16 (3) ◽  
Author(s):  
Jarnail Singh ◽  
Sunil Bhandari ◽  
M S Bisht
Keyword(s):  
Species Richness ◽  
Field Survey ◽  
Diversity Index ◽  
Mixed Forest ◽  
Bird Species ◽  
Bird Diversity ◽  
Species Evenness ◽  
Avian Diversity ◽  
Number Of Species

The avian diversity of Oak mixed forest in Pauri Garhwal district of Uttarakhand was studied during October 2019 to March 2020. Two strands of oak mixed forest located at different sites at 29º 22’-29º 75’ North and 78º, 10’ -78º,80’ East (1750 masl) were selected. Regular field survey was carried out during the morning and evening hours at each site. A total of 63 species of birds belonging to 07 orders and 31 families were recorded. The average bird diversity index H ¯was 3.202. The species richness was observed around 7.27 and species evenness was 0.72. The highest number of species was recorded at Ransi Oak mixed forest (63) and lowest number of bird species were recorded in Teka Oak mixed forest (60).

scholarly journals Insect Biodiversity in Organic and Non-Organic Rice Ecosystem in The District of Bantul

2016 ◽  
Vol 20 (1) ◽  
pp. 15
Author(s):  
Eka Armi Ovawanda ◽  
Witjaksono Witjaksono ◽  
Y. Andi Trisyono
Keyword(s):  
Species Richness ◽  
Rice Field ◽  
Insect Pest ◽  
Rice Farming ◽  
Species Evenness ◽  
Organic Rice ◽  
Number Of Species ◽  
Insect Biodiversity ◽  
Rice Ecosystem ◽  
Planting Season

Measuring biodiversity of insects is an essential part in management concept of insect pest populations based on ecology. This study examined the index of insect biodiversity by measuring species richness, species evenness and heterogeneity in organic and non-organic rice farming ecosystem. The sampling was conducted during the planting season of April–May 2015 and October–November 2015 at 44, 52 and 66 days after rice transplanting (DAT). High number of species richness (7 to 13 species) was found in the non-organic rice field (April–May 2015). In contrast, high number of species richness (22 to 33 species) was found in the organic rice field (October–November 2015). The species evenness and heterogeneity in the organic farming were generally higher than these in the non-organic rice in the both of planting season April–May 2015 and October–November 2015. Overall, the organic rice farming ecosystem can increase species richness, species evenness and heterogeneity of insect. INTISARI Mengukur biodiversitas serangga adalah salah satu bagian penting dalam konsep pengelolaan populasi serangga hama berbasis ekologi. Penelitian ini mengkaji indeks biodiversitas serangga dengan mengukur kekayaan spesies (species richness), kemerataan spesies (species evenness), dan keanekaragaman/kelimpahan spesies (heterogenity) pada sistem budidaya padi organik dan non-organik. Pengambilan sampel diperoleh pada saat musim tanam April–Mei 2015 dan musim tanam Oktober–November 2015 di 44, 52, dan 66 hari setelah tanam. Total kekayaan spesies tertinggi (7–13 spesies) ditemukan di lahan padi non-organik (April–Mei 2015). Sebaliknya, total kekayaan spesies (22–33 spesies) ditemukan di lahan padi organik (Oktober–November 2015). Kemerataan spesies dan heterogenitas di lahan padi organik secara umum lebih tinggi dibanding di padi non-organik pada kedua musim tanam April–Mei 2015 dan Oktober–November 2015. Secara keseluruhan, sistem budidaya di ekosistem padi organik dapat meningkatkan kekayaan spesies, kemerataan spesies, dan heterogenitas serangga.

scholarly journals Comparative Study of Understory Between Exotic Monoculture Plantation (Acacia Sp.) and Adjacent Natural Sal (Shorea Robusta) Forest

2020 ◽  
Vol 2 (6) ◽  
Author(s):  
Md. Tauhidor Rahaman ◽  
D. B. Gurung ◽  
Md. Najmus Sayadat Pitol
Keyword(s):  
Species Richness ◽  
Diversity Index ◽  
Acacia Auriculiformis ◽  
Species Evenness ◽  
Equitable Distribution ◽  
Shorea Robusta ◽  
Wiener Diversity Index ◽  
Monoculture Plantation ◽  
Sal Forest ◽  
Herb Species

To achieve forest management goal it is important to maintain biodiversity. This paper compares understory plant species diversity between exotic monoculture plantation (Acacia auriculiformis) and adjacent natural sal (Shorea robusta) forest. A total of 35 sample plots were taken by random sampling from six patches of adjacent natural sal forest and exotic monoculture plantation. Shannon-Wiener diversity index, species richness and evenness were calculated and compared. Result revealed that, a total of 2,218 plants of 42 species were recorded in natural sal (Shorea robusta) forest. Dominant families were Apocynaceae and Verbanaceae, having three species in each family. Shannon-Wiener diversity index was 2.1 and mean species richness was 14.4. On the contrary, 2,827 plants were found from 15 species in exotic monoculture (Acacia auriculiformis) plantation study area. Dominant family was Leguminosae family. Three species were found under Leguminosae family. Shannon-Wiener diversity index was 0.86 and mean species richness was 4.47. Therefore, Shannon diversity index and richness were significantly higher in natural sal forest as compared to exotic monoculture plantation. Species evenness of natural sal forest was 0.8 and 0.6 for monoculture plantation which indicates less equitable distribution of understory vegetation in monoculture than adjacent natural sal forest. With regard to herb species, evenness was significantly lower in monoculture plantation (0.03) as compared to natural sal forest (0.52). There was no equitable distribution for the herb species under monoculture plantation. Jaccard’s similarity index showed that 36% shrub species and 30% of herb species were same in exotic monoculture plantation area and adjacent natural sal forest.

scholarly journals Characterization of Peat Microbial Functional Diversity in Aerobic Rice Rhizosphere

2020 ◽  
Vol 43 (4) ◽  
Author(s):  
Nor Ayshah Alia Ali Hassan ◽  
Halimi Mohd Saud
Keyword(s):  
Species Richness ◽  
Microbial Activity ◽  
Functional Diversity ◽  
Rice Variety ◽  
Carbon Sources ◽  
Aerobic Rice ◽  
Species Evenness ◽  
Fertilizer Rate ◽  
H Index ◽  
Microbial Functional Diversity

Microorganisms in the rhizosphere possess numerous metabolic activities. The addition of inorganic substance such as fertilizer could affect the microbial functional diversity. This study was conducted to evaluate the effect of different rate of NPK fertilizer on microbial functional diversity in the rhizosphere of local aerobic rice variety. Aerobic rice variety MRIA 1 was used in this study. Peat was taken from a non-agricultural area in Klang, Malaysia. The effect of fertilizer rate was determined with 4 different rates (C = non-fertilized; T1 = 100 kg/ha NPK; T2 = 200 kg/ha NPK; T3 = 400 kg/ha NPK). Microbial functional diversity was performed using Biolog™ Ecoplate System and measured by microbial activities, such as average well color development (AWCD), species richness (R), Shannon-Weaver index (H index) and species evenness (E). As a result, microbial activity increased to 5.7% when fertilizer applied at T2, while fertilizer rate at T3 increased species richness by 3.2%. However, addition of fertilizer did not affect the H index while species evenness slightly decreased by 1.1% when applied at T3. Bacteria population was reduced when fertilizer added at T1. Fertilizer addition to the peat soil decreased the culturable population of nitrogen-fixing microbes while no effect was found on culturable fungal, actinomycetes and phosphate-solubilizing microbe population. Microbes in T2 utilized many carbon sources. Variation in carbon sources used by microbes was found when fertilizer was applied at different rates. D-cellobiose, pyruvic acid methyl ester, and L-serine were the carbon sources that influenced the microbial function in soil. It is concluded that fertilizer has an effect on microbial functional diversity in the peat rhizosphere of local aerobic variety. The recommended fertilizer rate (T2) increased the microbial activity while high fertilizer rate (T3) increased species richness and decreased species evenness.

scholarly journals Abundance and diversity of aquatic insects in two water bodies of Chittagong university campus

2015 ◽  
Vol 42 (1) ◽  
pp. 19-33
Author(s):  
Munira Nasiruddin ◽  
Mohammad Ali Azadi ◽  
Md Selim Reza
Keyword(s):  
Species Richness ◽  
Species Diversity ◽  
Aquatic Insects ◽  
Water Bodies ◽  
Species Evenness ◽  
University Campus ◽  
Abundance And Diversity

Abundance and diversity of aquatic insects was studied in two water bodies, (a pond and a lake) of Chittagong University campus during October 2009 to September 2010. A total of 4406 insects belonging to 32 genera, under 20 families and 6 orders were recorded. In both the water bodies, the representatives of the orders Hemiptera and Odonata were the most abundant groups. During the study period highest abundance of the total insects was recorded in November 2009 and the lowest in July 2010. Abundance of insects was comparatively higher in the pond habitat than in the lake. The Quotient of Similarity (QS) of the insects between the two water bodies was found to be the highest in October 2009 and lowest in July 2010. Species diversity, species richness and species evenness values of the lake were higher than that of the pond. Hydrophilus sp. and Sphaerodema sp. were the most dominant insects in the pond, while Chironomous sp. and Gerris sp. in the lake.Bangladesh J. Zool. 42(1): 19-33, 2014

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