scholarly journals “Brown” World Invertebrates Contradict “Green” World Biodiversity Theory

2008 ◽  
Vol 2008 ◽  
pp. 1-4 ◽  
Author(s):  
L. Brian Patrick ◽  
Lauchlan H. Fraser ◽  
Mark W. Kershner
Keyword(s):  
Nutrient Loading ◽  
Taxonomic Diversity ◽  
Conservation Strategies ◽  
Arthropod Community ◽  
Old Field ◽  
High Productivity ◽  
Limiting Nutrient ◽  
Npk Fertilizer ◽  
Productivity Theory ◽  
Terrestrial Biodiversity

Biodiversity-productivity theory predicts that ecosystems with increased productivity due to excessive limiting-nutrient loading will have decreased taxonomic diversity. In this 4-year study, we elevated productivity by adding NPK fertilizer to 20 m diameter plots in an old-field grassland to test the effects of anthropogenically mediated nutrient loading on plant and epigeal arthropod communities. While plants responded as predicted by the biodiversity-productivity theory, the epigeal arthropod community had highest species richness within the fertilized high-productivity treatments. We conclude that the contradictory response of the largely detrital-based epigeal community should alter conventional biodiversity-productivity theory and could affect terrestrial biodiversity conservation strategies.

The development from kinetic coefficients of a predictive model for the growth of Eichhornia crassipes in the field. IV. Application of the model to the Vernon Hooper Dam — a eutrophied South African impoundment

Bothalia ◽  
1984 ◽  
Vol 15 (3/4) ◽  
pp. 733-748 ◽  
Author(s):  
C. F. Musil ◽  
C. M. Breen
Keyword(s):  
Population Size ◽  
South African ◽  
Growth Rates ◽  
Eichhornia Crassipes ◽  
Nutrient Loading ◽  
Nutrient Inputs ◽  
Kinetic Coefficients ◽  
Limiting Nutrient ◽  
Population Sizes ◽  
Water Hyacinths

A model developed for  Eichhornia crassipes (Mart .) Solms was used to identify the limiting nutrient in the Vernon Hooper Dam and to predict population sizes, yields, growth rates and frequencies and amounts of harvest under varying conditions of nutrient loading and climate. Predicted data were used to evaluate the effectiveness of harvesting measures currently being employed for controlling both nutrient inputs and the population size in this impoundment. Predictions o f the population size, before harvesting was initiated, generally compared favourably with th a t estimated visually. Predictions of the quantities of P that could be removed daily by a 20 ha population indicate that such a population in the impoundment could reduce P concentrations in the epilimnion during summer stratification to levels limiting for algae. This may explain the observed reduction in algal concentrations since the introduction of harvesting. Estimates of the amounts and frequencies of harvest required to contain the predicted potential yields of a 20 ha population indicate that 100 metric tonnes of fresh water hyacinths harvested daily from the impoundment, under present conditions of reduced nutrient loading, are adequate during winter, but not during summer.

scholarly journals The productivity-biodiversity relationship varies across diversity dimensions

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Philipp Brun ◽  
Niklaus E. Zimmermann ◽  
Catherine H. Graham ◽  
Sébastien Lavergne ◽  
Loïc Pellissier ◽  
...  
Keyword(s):  
Land Use ◽  
Molecular Phylogeny ◽  
Plant Species ◽  
Phylogenetic Diversity ◽  
Taxonomic Diversity ◽  
Land Use Intensity ◽  
Species Dominance ◽  
High Productivity ◽  
External Constraints ◽  
Species Similarity

AbstractUnderstanding the processes that drive the dramatic changes in biodiversity along the productivity gradient remains a major challenge. Insight from simple, bivariate relationships so far has been limited. We combined >11,000 community plots in the French Alps with a molecular phylogeny and trait information for >1200 plant species to simultaneously investigate the relationships between all major biodiversity dimensions and satellite-sensed productivity. Using an approach that tests for differential effects of species dominance, species similarity and the interplay between phylogeny and traits, we demonstrate that unimodal productivity–biodiversity relationships only dominate for taxonomic diversity. In forests, trait and phylogenetic diversity typically increase with productivity, while in grasslands, relationships shift from unimodal to declining with greater land-use intensity. High productivity may increase trait/phylogenetic diversity in ecosystems with few external constraints (forests) by promoting complementary strategies, but under external constraints (managed grasslands) successful strategies are similar and thus the best competitors may be selected.

Influence of area, altitude and hydroperiod on macroinvertebrate communities in southern Brazil wetlands

2007 ◽  
Vol 58 (11) ◽  
pp. 993 ◽  
Author(s):  
Cristina Stenert ◽  
Leonardo Maltchik
Keyword(s):  
Biological Diversity ◽  
Neotropical Region ◽  
Conservation Strategies ◽  
Macroinvertebrate Communities ◽  
Southern Brazil ◽  
Wetland Area ◽  
High Productivity ◽  
Intermittent Wetlands ◽  
Natural Wetlands ◽  
Richness Patterns

Wetlands are important ecosystems in southern Brazil because they show high productivity and biological diversity. However, conservative data indicate that ~90% of the wetlands have disappeared as a result of agricultural expansion. In this sense, the understanding of species composition and richness patterns in fragmented and natural wetlands is a priority for biodiversity conservation strategies. The main goal of the present study was to determine how much variation in macroinvertebrate richness and composition is explained by wetland area, hydroperiod and altitude. This survey was carried out in an extensive area of the Neotropical region (~280000 km2 – southern Brazil) with a large number of wetland systems (72) and covering a wide gradient of altitude and wetland surface area. The macroinvertebrate richness was higher in permanent wetlands than intermittent ones, and intermittent wetlands supported a macroinvertebrate composition that clearly differed from those of permanent wetlands. Macroinvertebrate richness was positively affected by wetland area; however, this relationship was significant only in permanent wetlands. There is a need to promote conservation of all wetland systems in southern Brazil, regardless of their hydroperiod and area. These arguments are essential to develop conservation and management programs of wetlands in this region.

Impacts of Agricultural Nutrient Loading on Finnish Watercourses

1993 ◽  
Vol 28 (3-5) ◽  
pp. 461-471 ◽  
Author(s):  
L. Kauppi ◽  
O.-P. Pietiläinen ◽  
S. Knuuttila
Keyword(s):  
Coastal Waters ◽  
Algal Blooms ◽  
Nutrient Loading ◽  
Drainage Basin ◽  
Agricultural Practices ◽  
Eutrophic Lakes ◽  
Green Algal ◽  
Limiting Nutrient ◽  
Agricultural Regions

Eutrophication of lakes, rivers and coastal waters is the main environmental problem caused by agriculture in Finland. Water quality of most Finnish watercourses is good or excellent, but in the intensively cultivated region of southern and western Finland the turbidity of water as well as algal blooms are a common problem. Generally, phosphorus is the limiting nutrient for primary production in Finnish lakes, but in eutrophic lakes and coastal waters the role of nitrogen becomes more important. Nitrogen from agriculture enters the watercourses mainly in dissolved form. By contrast, most phosphorus is transported in association with small particles. According to bioassays the algal availability of this paniculate P is very low. Therefore, the eutrophying effect of agriculture can be estimated on the basis of dissolved nutrients. In shallow lakes, typical in agricultural regions, the release of dissolved P from the bottom sediment often induces the development of N2-fixing blue- green algal blooms. In some cases the internal load may exceed the external load. For the recovery of such a lake the introduction of better agricultural practices in the drainage basin has to be coupled with in-lake measures.

scholarly journals Modification of landscape as promoter of change in structure and taxonomic diversity of reptile´s communities: an example in tropical landscape in the central region of Mexico

2018 ◽  
Vol 28 ◽  
pp. 33-49 ◽  
Author(s):  
Christian Berriozabal-Islas ◽  
Aurelio Ramírez-Bautista ◽  
Raciel Cruz-Elizalde ◽  
Uriel Hernández-Salinas
Keyword(s):  
Taxonomic Diversity ◽  
Evergreen Forest ◽  
Conservation Strategies ◽  
Species Loss ◽  
Number Of Species ◽  
Structure Of Communities ◽  
Tropical Evergreen Forest ◽  
Sierra Madre ◽  
Grazing Area

The degree of species loss was assessed by comparing the structure of communities and species diversity of reptiles from three different environments, one natural (tropical evergreen forest [TEF]) and two modified (shaded coffee plantation [SCP] and grazing area [GA]) from the mid portion of the Sierra Madre Oriental, Mexico. The results showed 29 species, 18 in TEF, 13 in SCP and 12 in GA. According to the abundance of each species, the reptile structure for TEF and SCP was similar and they both differed from GA, while the diversity (effective number of species) was the highest for TEF. The percentage of number of species from TEF accounted for 28% more species than SCP and GA, which indicated a species loss of about 70% in disturbed environments. The values of beta diversity were the highest between TEF and GA, followed by SCP and GA and to a lesser degree between TEF and SCP, which indicates that TEF showed a high number of exclusive species. Our results suggest that carrying out long-term studies that include richness and diversity in environments with different levels of disturbance, in addition to including characteristics of natural history, might enhance the development of more efficient conservation strategies for these species.

scholarly journals A Comparison of Amphibian and Reptile Diversity Between Disturbed and Undisturbed Environments of Salvatierra, Guanajuato, Mexico

2019 ◽  
Vol 12 ◽  
pp. 194008291982999
Author(s):  
Adrian Leyte-Manrique ◽  
Buelna-Chontal Abel Antonio ◽  
Torres-Díaz Miguel Alejandro ◽  
Christian Berriozabal-Islas ◽  
Carlos Alberto Maciel-Mata
Keyword(s):  
Deciduous Forest ◽  
Taxonomic Diversity ◽  
Conservation Strategies ◽  
Tropical Deciduous Forest ◽  
Taxonomic Distinctness ◽  
Reptile Species ◽  
Sceloporus Grammicus ◽  
Vulnerability Score ◽  
Different Levels

Amphibians and reptiles are two groups of vertebrates that are sensitive to changes in their environment. These changes are mostly caused by human activities, which affect the abundance, composition, and distribution of these vertebrates. In this study, we compare the richness and taxonomic diversity of herpetofauna between undisturbed environments (tropical deciduous forest = TDF) and disturbed environments (corn fields = CF) near the towns of Urireo (URI) and San Nicolas de los Agustinos (SNA) in Salvatierra, Guanajuato. We recorded a total of 19 species in the two locations (4 amphibian and 15 reptile species). At the URI locality, 12 species were recorded in CF and 10 in TDF. At the SNA locality, eight species were recorded in CF and seven species in TDF. In addition, we found that overall taxonomic distinctness was greater at URI than SNA across both types of vegetation, with the highest diversity found in TDF of URI. Seven of the 19 species recorded are current allocated to some protection category of NOM-059-SEMARNAT-2010: Lithobates neovolcanicus, Kinosternon integrum, Sceloporus grammicus, Lampropeltis polyzona, Masticophis mentovarius, Salvadora bairdi, and Thamnophis melanogaster differing from other mechanisms such as the International Union for Conservation of Nature and Environmental Vulnerability Score. Our results suggest that carrying out long-term studies that include diversity and taxonomic distinctness in environments with different levels of disturbance, in addition to including characteristics of natural history, might enhance the development of more efficient conservation strategies for these vertebrates.

scholarly journals Sequential nutrient uptake as a potential mechanism for phytoplankton to maintain high primary productivity and balanced nutrient stoichiometry

2017 ◽  
Vol 14 (9) ◽  
pp. 2469-2480 ◽  
Author(s):  
Kedong Yin ◽  
Hao Liu ◽  
Paul J. Harrison
Keyword(s):  
Nutrient Uptake ◽  
Water Column ◽  
Primary Productivity ◽  
Nutrient Ratios ◽  
Vertical Profiles ◽  
Nutrient Stoichiometry ◽  
High Productivity ◽  
Limiting Nutrients ◽  
Limiting Nutrient

Abstract. We hypothesize that phytoplankton have the sequential nutrient uptake strategy to maintain nutrient stoichiometry and high primary productivity in the water column. According to this hypothesis, phytoplankton take up the most limiting nutrient first until depletion, continue to draw down non-limiting nutrients and then take up the most limiting nutrient rapidly when it is available. These processes would result in the variation of ambient nutrient ratios in the water column around the Redfield ratio. We used high-resolution continuous vertical profiles of nutrients, nutrient ratios and on-board ship incubation experiments to test this hypothesis in the Strait of Georgia. At the surface in summer, ambient NO3− was depleted with excess PO43− and SiO4− remaining, and as a result, both N : P and N : Si ratios were low. The two ratios increased to about 10 : 1 and 0. 45 : 1, respectively, at 20 m. Time series of vertical profiles showed that the leftover PO43− continued to be removed, resulting in additional phosphorus storage by phytoplankton. The N : P ratios at the nutricline in vertical profiles responded differently to mixing events. Field incubation of seawater samples also demonstrated the sequential uptake of NO3− (the most limiting nutrient) and then PO43− and SiO4− (the non-limiting nutrients). This sequential uptake strategy allows phytoplankton to acquire additional cellular phosphorus and silicon when they are available and wait for nitrogen to become available through frequent mixing of NO3− (or pulsed regenerated NH4). Thus, phytoplankton are able to maintain high productivity and balance nutrient stoichiometry by taking advantage of vigorous mixing regimes with the capacity of the stoichiometric plasticity. To our knowledge, this is the first study to show the in situ dynamics of continuous vertical profiles of N : P and N : Si ratios, which can provide insight into the in situ dynamics of nutrient stoichiometry in the water column and the inference of the transient status of phytoplankton nutrient stoichiometry in the coastal ocean.

The role of environmental, geographical, morphometric and spatial variables on plankton communities in lakes of the arid Patagonian plateaus

2020 ◽  
Vol 42 (2) ◽  
pp. 173-187
Author(s):  
Sol Porcel ◽  
Griselda Chaparro ◽  
M Cristina Marinone ◽  
Juan F Saad ◽  
Julio Lancelotti ◽  
...  
Keyword(s):  
Variation Partitioning ◽  
Null Model ◽  
Taxonomic Diversity ◽  
Conservation Strategies ◽  
High Dispersion ◽  
Spatial Effects ◽  
Spatial Factors ◽  
Zooplankton Communities ◽  
Planktonic Communities

Abstract Species diversity is one of the most informative community metrics and is influenced by regional and local factors. We studied the spatial patterns of taxonomic and functional phyto- and zooplankton diversity in 33 lakes from two basaltic plateaus of the arid Patagonia. The aims of our study were to evaluate α, β and γ taxonomic diversity of phyto- and zooplankton; to assess the influence of environmental, spatial, geographical and morphometric factors on phyto- and zooplankton communities and to compare the influence of these variables on the taxonomic and functional composition. β1-diversity (within plateaus) was the major component for phytoplankton, rotifers and microcrustaceans taxonomic regional diversities. Planktonic communities were mainly constrained by macrophytes, fish, conductivity, dissolved organic carbon, altitude and spatial factors. The high dispersion of small individuals within plateaus tends to homogenize these communities, as indicated by null model results and the high explanation of fine-scale spatial factors in variation partitioning. This knowledge contributes to explaining the diversity patterns of planktonic communities of these valuable environments and to develop conservation strategies, considering both environmental heterogeneity and spatial effects.

Growth and nutrient dynamics of western hemlock with conventional or exponential greenhouse fertilization and planting in different fertility conditions

2005 ◽  
Vol 35 (4) ◽  
pp. 1002-1016 ◽  
Author(s):  
B J Hawkins ◽  
D Burgess ◽  
A K Mitchell
Keyword(s):  
Nutrient Dynamics ◽  
Nutrient Loading ◽  
Slow Release ◽  
Field Performance ◽  
Tsuga Heterophylla ◽  
Western Hemlock ◽  
Constant Rate ◽  
Npk Fertilizer ◽  
Northern Forests ◽  
Outdoor Nursery

In many northern forests, low nutrient availability constrains growth of young trees. We tested the efficacy of exponential nutrient application to load western hemlock (Tsuga heterophylla (Raf.) Sarg.) seedlings with nutrients to enhance field performance. Seedlings were grown with conventional, constant-rate fertilization (100 mg N·L–1) or with exponentially increasing fertilization at rates of 2% and 3% per day in a greenhouse. Growth and nutrient allocation were characterized. Seedlings from the three greenhouse treatments were then planted in an outdoor nursery experiment for 2 years with NPK fertilizer applied at 10, 25, or 100 mg N·L–1, and in a 3-year field experiment with and without slow-release fertilizer. Seedling height, biomass, and nutrient concentration did not differ greatly among exponential or constant-rate fertilization treatments in the greenhouse. The influence of postplanting fertility, both in the nursery and in the field, outweighed the effect of greenhouse exponential nutrient application. In the outdoor nursery, seedlings from all greenhouse treatments showed increased growth with higher rates of fertilization. In the field, there were no differences in growth among seedlings from the three greenhouse treatments, but fertilization at planting increased growth. The capacity for nutrient loading in container-grown western hemlock was likely exceeded because large quantities of N were applied in all treatments.

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