scholarly journals Species Diversity Enhances Predator Growth Rates

2007 ◽  
Vol 2007 ◽  
pp. 1-5 ◽  
Author(s):  
Mark H. Olson ◽  
Robert P. Jacobs ◽  
Eileen B. O'Donnell
Keyword(s):  
Species Diversity ◽  
Growth Rates ◽  
Diversity Index ◽  
Micropterus Salmoides ◽  
Reciprocal Effects ◽  
Strong Positive Correlation ◽  
Negative Effects ◽  
Total Fish ◽  
Predator Abundance ◽  
Underlying Mechanisms

Predators can be important top-down regulators of community structure and are known to have both positive and negative effects on species diversity. However, little is known about the reciprocal effects of species diversity on predators. Across a set of 80 lakes in Connecticut, USA, we found a strong positive correlation between prey species diversity (using the Shannon-Weiner Diversity Index) and growth rates of largemouth bass (Micropterus salmoides). This correlation was strongest for small predators and decreased with body size. Although the underlying mechanisms are not known, the correlation is not driven by total fish abundance, predator abundance, or productivity.

scholarly journals Carbon stocks of homestead forests have a mitigation potential to climate change in Bangladesh

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tarit Kumar Baul ◽  
Tajkera Akhter Peuly ◽  
Rajasree Nandi ◽  
Lars Holger Schmidt ◽  
Shyamal Karmakar
Keyword(s):  
Species Diversity ◽  
Stand Structure ◽  
Diversity Index ◽  
Carbon Stocks ◽  
Small Scale ◽  
Species Diversity Index ◽  
C Stocks ◽  
Homestead Forests ◽  
C Stock ◽  
Low Altitude

AbstractA total of 176 homestead forests at three altitudes in the Chittagong Hill Tracts, Bangladesh were randomly surveyed to estimate carbon (C) stocks and how stand structure affects the biomass C. All woody vegetations were measured, and litter and soil (0–30 cm depth) were sampled. The tree biomass C stock in the top two altitude forests was up to 37–48% higher than in low altitude, owing to significantly higher tree density and species diversity. An increase in species diversity index by one unit increased the biomass stock by 23 Mg C ha−1. The C stock of litterfall in low altitude forests was 22–28% higher than in the top two altitude due to the deposition of litters downslope and deliberate use of mulch for soil improvement and conservation, resulting in up to 5% higher total soil C. The topsoil C was 10–25% higher than the deeper soil, depending on the altitude. The forest stored 89 Mg C ha−1, indicating a potential for C sequestration in trees outside forest. This study would help policymakers to strengthen the recognition of small-scale forests for mitigation in REDD + (reducing emissions from deforestation and forest degradation, the role of conservation, sustainable management of forests, and enhancement of forest carbon stocks) and support owners through C credits from sustainably managed forests.

scholarly journals What Does Productivity Really Mean? Towards an Integrative Paradigm in the Search for Biodiversity-Productivity Relationships

2013 ◽  
Vol 41 (1) ◽  
pp. 36 ◽  
Author(s):  
Liangjun HU ◽  
Qinfeng GUO
Keyword(s):  
Species Richness ◽  
Species Diversity ◽  
Biomass Production ◽  
Real Root ◽  
Spatial Scaling ◽  
Ecological Processes ◽  
The Real ◽  
Community Or ◽  
Per Se ◽  
Underlying Mechanisms

How species diversity relates to productivity remains a major debate. To date, however, the underlying mechanisms that regulate the ecological processes involved are still poorly understood. Three major issues persist in early efforts at resolution. First, in the context that productivity drives species diversity, how the pathways operate is poorly-explained. Second, productivity  per se varies with community or ecosystem maturity. If diversity indeed drives productivity, the criterion of choosing appropriate measures for productivity is not available. Third, spatial scaling suggests that sampling based on small-plots may not be suitable for formulating species richness-productivity relationships (SRPRs). Thus, the long-standing assumption simply linking diversity with productivity and pursuing a generalizing pattern may not be robust. We argue that productivity, though defined as ‘the rate of biomass production’, has been measured in two ways environmental surrogates and biomass production leading to misinterpretations and difficulty in the pursuit of generalizable SRPRs. To tackle these issues, we developed an integrative theoretical paradigm encompassing richer biological and physical contexts and clearly reconciling the major processes of the systems, using proper productivity measures and sampling units. We conclude that loose interpretation and confounding measures of productivity may be the real root of current SRPR inconsistencies and debate.

scholarly journals Morphofunctional changes of phytoplankton community during pluvial anomaly in a tropical reservoir

2015 ◽  
Vol 75 (3) ◽  
pp. 628-637 ◽  
Author(s):  
FRA Câmara ◽  
O Rocha ◽  
EKR Pessoa ◽  
S Chellappa ◽  
NT Chellappa
Keyword(s):  
Species Diversity ◽  
Dissolved Oxygen ◽  
Oxygen Content ◽  
Phytoplankton Community ◽  
Diversity Index ◽  
Hydrodynamic Instability ◽  
Electrical Conductance ◽  
Northeastern Brazil ◽  
Tropical Reservoir ◽  
Cyanobacterial Species

AbstractThe present study focuses on the structure and function of phytoplankton community during periods of marked changes in hydrological traits, influenced by an atypical climatic event (La Niña) and its impact on Armando Ribeiro Gonçalves Reservoir of Rio Grande do Norte, situated in the Caatinga biome of northeastern Brazil. The main questions addressed were: What are the effects of environmental factors on the temporal variation of Morphologically Based Functional Group (MBFG) of phytoplankton community? How does the composition of cyanobacterial species shift in relation to high and low trends of phytoplankton diversity? The samples were collected monthly during 2008-2009 and analyzed for pH, temperature, electrical conductivity, dissolved oxygen content and the nutrients, such as, nitrate-nitrogen, ammoniacal nitrogen, total nitrogen and orthophosphate. Phytoplankton samples were collected for both qualitative and quantitative analyses to evaluate species richness index and species diversity index. The data was divided into two distinct hydrodynamic periods of instability and stability. The results demonstrate considerable changes in dissolved oxygen content, water transparency and nitrogen nutrients, which directly influenced the MBFG of phytoplankton community in space and time. The instability of reservoir water was caused by heavy rainfall, which exerts atypical external disturbances. The seasonal variation of MBFG demonstrates a change in cyanobacterial composition and their diversity during instability and stability periods. MBFG VII, composed by colonial cyanobacteria with mucilage, was associated with reduced values of electrical conductance and alterations in pH. The predominance of filamentous species with heterocyst (MBFG III) occurs only during the hydrodynamic stability period and did not show significant association with analyzed parameters. The co-dominance of MBGFs III, V and VII along with high species diversity of phytoplankton community occurred during the second hydrodynamic instability period which was associated with the reduction in water temperature. It is concluded that the decrease in cyanobacterial species dominance and the general increase in the diversity of phytoplankton community are influenced by pluvial anomaly. The higher water level during the period of pluvial anomaly resulted in nutrient pulse and the mixing of water column in the reservoir, which determined the MBPG phytoplankton community distribution.

scholarly journals Distance Effects on Diversity and Abundance of the Flower Visitors of Ocimum kilimandscharicum in the Kakamega Forest Ecosystem

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Hellen K. Mandela ◽  
Mugatsia H. Tsingalia ◽  
Mary Gikungu ◽  
Wilbur M. Lwande
Keyword(s):  
Species Diversity ◽  
Diversity Index ◽  
Land Use Changes ◽  
Species Abundance ◽  
Diversity Indices ◽  
Forest Edge ◽  
Flower Visitors ◽  
Kakamega Forest ◽  
Species Invasions ◽  
Wiener Diversity Index

Pollination is an important ecosystem service in the maintenance of biodiversity and most importantly in food production. Pollination is on the decline due to habitat loss, exotic species invasions, pollution, overharvesting, and land use changes. This study analyzed the abundance and diversity of flower visitors’ of Ocimum kilimandscharicum in Kakamega forest with increasing distance from the forest edge. Data were collected through direct observation and sweep netting. Six study sites were identified along two transects each 2.5 km long and labeled A to F. Distance in metres from the forest edge to each site was A=221, B=72, C=83, D=198, E=113, and F=50. Sampling was done from 7:30 am to 4:00 pm, three days in a week for five months consecutively. Diversity indices of different flower visitors were calculated using the Shannon-Wiener diversity index. One-way analysis of variance was used to compare differences between sites and a two-sample t-test was used to identify mean significant differences in species diversity between the closest and the furthest sites. A total of 645 individuals belonging to 35 species were captured from 4 families. The highest diversity was at site F (H’= 2.38) which was closest to the forest edge and the lowest diversity was from site A (H’=1.44) which was furthest from the forest edge. Distance from the forest edge significantly influenced species diversity (F(3, 20)=14.67, p=0.024). Distance from the forest edge also significantly influenced species abundance between the furthest sites A, D, and E and the nearest sites F, B, and C to the forest edge (t=4.177; p=0.0312) and species richness (t=3.2893; p=0.0187). This study clearly demonstrates that Ocimum kilimandscharicum flower visitors play essential roles in pollination and their higher number of visits translates into higher numbers of seeds set. Many of these pollinators are associated with the forest and hence the need to conserve the Kakamega forest as a source pool for pollinators.

scholarly journals Effects of grazing on plant species diversity and above ground biomass in a Trans- Himalayan Rangeland

1970 ◽  
Vol 17 (1) ◽  
pp. 25-31 ◽  
Author(s):  
Anita Pokharel ◽  
Madhu Chhetri ◽  
Chiranjibi P Upadhyaya
Keyword(s):  
Species Diversity ◽  
Species Composition ◽  
Plant Species ◽  
Diversity Index ◽  
Livestock Grazing ◽  
Above Ground Biomass ◽  
Ground Biomass ◽  
Grazing Effect ◽  
Significant Difference ◽  
Palatable Species

Limited information is available on the species composition, above ground biomass and its relations to grazing in a trans-Himalayan rangeland. Its assessment is essential for long term conservation and management. In the present study, we compared species composition, phenology, diversity index and biomass between controlled (without grazing) and open (free grazing) plots to assess the effects of grazing in the selected experimental sites of Upper Mustang during July and November 2005. Species encountered were classified as high, medium, low and non palatable and in three life form categories-grasses, shrubs and forbs. The experimental sites are dominated by forbs (80%) followed by grasses (15%) and shrubs (5%). Disturbance caused by grazing affects the phenological characteristics of the plant community. Result also reveals that species diversity, maximum possible diversity, evenness and species richness was higher in the grazed plots during July and November. A comparison of the aboveground biomass in July showed that mean percentage biomass of high, medium and low palatable species is higher in ungrazed plots. In November, the percentage biomass of only medium palatable species was higher in ungrazed plots and rest of the category is higher in grazed plots. Significant difference in July, a peak growing seasons for most of the plant species in the region reveals that the pasture has impact of livestock grazing. Keywords: Biomass, diversity, grazing effect, rangeland, species Banko Janakari: A journal of forestry information for Nepal Vol.17(1) 2007 pp.25-31

scholarly journals Vegetation analysis and plant diversity in Pinus Jantho Forest (PJF) nature reserve, Aceh Besar

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
HILMINA ITAWAMERNI ◽  
SAIDA RASNOVI ◽  
ZUMAIDAR ZUMAIDAR
Keyword(s):  
Species Diversity ◽  
Plant Species ◽  
Nature Reserve ◽  
Diversity Index ◽  
Systematic Sampling ◽  
Vegetation Analysis ◽  
High Level ◽  
Piper Aduncum ◽  
Important Value Index ◽  
Pinus Merkusii

Pinus Jantho Forest (PJF) Nature Reserve has unique characteristics and distinctive ecosystem that plays an important role in the preservation of germplasm and the protection of natural resources. The sustainability of the PJF Nature Reserve is strongly determined by vegetation of its constituents. Therefore, an effort is needed to help its management properly, one of which is by knowing the diversity of plants that make up the community in PJF Nature Reserve. The purpose of this research is to analyze the composition and diversity of plant species in PJF Nature Reserve. Data collection and sampling were done using multiple square method. The plots were laid out by systematic sampling. PJF Nature Reserve composed of 111 species from 46 family. The seedling and understorey have the highest number individuals (1028 in total). Then there are 240 individuals at sapling level, 108 individuals at pole, and 72 individuals for tree.  The Euphorbiaceae family has the largest number of species (11 species). The highest Important Value Index (IVI) for seedlings and understorey, sapling and pole, and tree respectively were Chloranthus elatior (11.09%), Piper aduncum (21.90% and 19.32%), and Pinus merkusii (25.52%). The Diversity Index indicates a high level of plant species diversity (3.25-3.63).

scholarly journals KEANEKARAGAMAN JENIS ANGGREK ALAM (Orchidaceae) BERDASARKAN KETINGGIAN TEMPAT DI GUNUNG POTENG CAGAR ALAM RAYA PASI KOTA SINGKAWANG PROVINSI KALIMANTAN BARAT

2020 ◽  
Vol 8 (3) ◽  
Author(s):  
Novita Putri Sesar ◽  
Iskandar A M ◽  
Togar Fernando Manurung
Keyword(s):  
Species Diversity ◽  
Environmental Factors ◽  
Nature Reserve ◽  
Diversity Index ◽  
Economic Value ◽  
Survey Method ◽  
Species Diversity Index ◽  
Orchid Species ◽  
West Kalimantan ◽  
Medium Range

Natural orchids are one of the flora in Mount Poteng which is included of Raya Pasi Nature Reserve located at Singkawang City, West Kalimantan Province. Orchids have economic value for source of income and be beneficial to ecology that needs to be protected. The altitudes and environmental factors strongly affected the presence of orchid species.The research aims to record the diversity of natural orchids species based on the altitudes place in Mount Poteng. The research was conducted on February 28 until March 28, 2020. This research uses survey method. The research sample was taken using double plots method and to determine sample plots locations is conducted by purposive. The total number of the sample plots is 16 plots and each plot measure 20 by 50 meters. Based on the result of research found 19 species of natural orchids that consist of 348 individuals. The results analysis of the diversity index of orchid species in whole of altitudes at Mount Poteng is 1,338 that is included medium range. The highest species diversity index of 1,300 occurred at altitude of 400-500 m asl and the lowest species diversity index at altitude of 700-725 m asl that is 0,594. Orchid species which found in whole of altitudes is Dendrobium crumenatum. Furthermor, there were found the orchid species on certain heights are Cleisostoma scortechinii, Cordiglottis filiformis, Ludisia discolor, and Phalaenopsis pantherina at altitude of 400-500 m asl and species of Bromheadia finlaysoniana and Pomatocalpa latifolia found at altitude of 700-725 m asl.Keywords: altitudes, mount poteng, orchids, species diversity

scholarly journals Baseline Assessments of Wildlife Biodiversity Within Selected Areas of Central Visayas, Philippines

2021 ◽  
Vol 6 (2) ◽  
pp. 27-34
Author(s):  
RP Jose ◽  
WA Aureo ◽  
CI Narido ◽  
TD Reyes Jr ◽  
MB Sarnowski
Keyword(s):  
Species Richness ◽  
Species Diversity ◽  
Diversity Index ◽  
Population Trends ◽  
Species Richness And Diversity ◽  
Natural Park ◽  
Biodiversity Inventories ◽  
Baseline Information ◽  
High Diversity ◽  
Areas Of Protection

A comprehensive inventory of faunal biodiversity was conducted within three Key Biodiversity Areas of Central Visayas. Mt. Bandilaan Natural Park (MBNP), Balinsasayao Twin Lakes Natural Park (BTLNP), and Rajah Sikatuna Protected Landscape (RSPL). Three primary wildlife groups were surveyed: bats, birds and amphibians. Species diversity and population trends were then analyzed to assess areas of biodiversity importance. RSPL generally had the highest species richness and diversity index while MBNP consistently had the lowest. When pooled. The surveyed areas resulted in a high diversity index and rate of endemicity showing the importance of multiple areas of protection. These findings can be utilized to prioritize habitat protection as well as to serve as a baseline information for future biodiversity inventories. J. Biodivers. Conserv. Bioresour. Manag. 2020, 6(2): 27-34

scholarly journals Keanekaragaman Pari Hasil Tangkapan Nelayan di TPI Karangantu Banten

2021 ◽  
Vol 9 (3) ◽  
pp. 257-266
Author(s):  
Erreull Isyhadu Putri ◽  
◽  
Dinda Rizqi ◽  
Fenia Alya ◽  
Tia Azizah
Keyword(s):  
Species Diversity ◽  
Literature Review ◽  
Diversity Index ◽  
Conservation Status ◽  
Habitat Characteristics ◽  
Species Diversity Index ◽  
Interview Method

This study aims to determine the diversity of rays caught by fishermen in TPI Karangantu Banten. This research uses interview method and literature review. The discussion of the observations includes classification, habitat, characteristics, and conservation status. The results of this study indicate that there is a diversity of rays, namely the results of the families obtained from the observations are Rhinopteridae, Dasyatidae, and Gymnuridae). From the results of the calculation of the species diversity index using the Shannon Wiener formula, it is included in the medium category. This diversity can be used as knowledge and inventory for biodiversity, especially the chondrichthyes class in TPI Karangantu, Serang, Banten.

scholarly journals The The diversity and abundance of Hymenoptera insects on tidal swamp rice field in Indragiri Hilir District, Indonesia

2020 ◽  
Vol 21 (3) ◽  
Author(s):  
ZAHLUL IKHSAN ◽  
HIDRAYANI ◽  
YAHERWANDI ◽  
HASMIANDY HAMID
Keyword(s):  
Species Diversity ◽  
Rice Field ◽  
Diversity Index ◽  
Human Life ◽  
Similarity Index ◽  
Pitfall Trap ◽  
Vital Role ◽  
Tidal Swamp ◽  
Abundance And Diversity ◽  
Number Of Individuals

Abstract. Ikhsan Z, Hidrayani, Yaherwandi, Hamid H. 2020. The diversity and abundance of Hymenoptera insects on tidal swamp rice field in Indragiri Hilir District, Indonesia. Biodiversitas 21: 1020-1026. Hymenoptera is one of the four largest insect orders and it plays a vital role in human life as pollinators, parasitoids, and predators. Hymenoptera parasitoids are particularly important as agents of biological control of pest. The objective of this research was to study the diversity and abundance of Hymenoptera on tidal swamp rice field in Indragiri Hilir District, Riau Province, Indonesia. Samplings were conducted in 3 sub-districts of rice production centers, namely Batang Tuaka, Keritang and Reteh, using four trapping techniques (i.e. insect net, malaise trap, pitfall trap, and yellow pan trap). Shannon diversity index (H '), Krebs evenness index (E), and Jaccard similarity index (Is) were calculated. We found 4,701 individuals consisting of 39 families and 319 species of Hymenoptera at the three studied areas. Tidal swamp rice in Indragiri Hilir District had a high species diversity of Hymenoptera parasitoids and Hymenoptera predators, but a moderate species diversity of Hymenoptera pollinators. Species diversity and evenness of Hymenoptera parasitoids and predators were higher in Keritang than in Batang Tuaka and Reteh. The families of Formicidae, Braconidae, Ichneumonidae, and Scelionidae had the highest number of species, while Formicidae, Scelionidae, Diapriidae, and Braconidae had the highest number of individuals. Based on these findings, the abundance and diversity of Hymenoptera insects in Indragiri Hilir District have the potentials to be developed as biological agents to control pests on tidal swamp rice in this area.

Sign in / Sign up

Export Citation Format

Share Document