e-learningsite.com

free essays
Uncategorized

Ecology Question 1

ECOLOGY 7

Ecology

Question1

Theproducts of primary production in terrestrial ecosystems becomeavailable to secondary producers in the soil through energy transfer.Secondary producers in the soils usually obtain energy from theprimary producers, when they obtain nutrients from the primaryproducers. Primary producers have the ability to supply nutrients tothe soil, which become utilized by the secondary producers in thesoil for instance, leguminous plants fix nitrogen to the soil.

Question2

Thereis a great comparison amid the rhizosphere and bulk soils, in termsof, abiotic and biotic factors. The rhizosphere soil is a highlyfavorable environment for activity and proliferation of variousmicroorganisms. However, the bulk soil does not support manymicroorganisms like rhizosphere do. Therefore, most biotic factorsare supported in rhizosphere soils, while bulk soils support bothbiotic and abiotic factors.

Question3

Microbesare exceedingly vital in supporting primary production therefore, assecondary producers, they are capable of supporting transfer ofenergy in an ecosystem. In the microbial secondary producer pool,there are different microbes that assist in the transfer of energy inthe ecosystem. For instance, microbes in the soil such as thebacteria are capable of converting free nitrogen into nitrates, whichis utilized by plants. Other microbes also take part in otherprocesses such as fermentation. Some of the products of secondaryproduction include food such as yogurt and cheese, solvents such asethanol, and food additives. On the other hand, energy and gas areproduced as by-products. This process is efficient since it can takeplace voluntarily.

Question4

Microbeshave a critical role to play in the nitrogen cycle. The nitrogencycle processes, which include nitrogen fixation, nitrogenmineralization, nitrogen immobilization, nitrification, anddenitrification, require microbes. Nitrogen fixation is theconversion of nitrogen to ammonia, while nitrogen mineralization isthe transformation of organic nitrogen to ammonium. On the otherhand, nitrification entails the transformation of ammonium tonitrate, while denitrification entails the reduction of nitrates todinitrogen and gaseous oxide (Slade,2007).

Question5

Primaryproduction in plants can be quantified by the 14Cmethod. In this method, a labeled tracer is utilized in quantifyingassimilated carbon. In order to establish the uptake, it is vital toknow the concentration of dissolved inorganic carbon (DIC) occurringin the sample water, quantity of 14C-DICadded, and quantity of 14Cretained at the conclusion of the experiment. On the other hand,secondary production in microbes can be quantified through measuringthe cell mass, or rate of synthesis of cells. Cell mass are taken atdifferent times, after which secondary production is calculated.

Question6

Protozoaare grouped into ciliates, amoebae, and flagellates. These groupsoccur in vast numbers therefore, they can be calculated per gram ofsoil. Protozoa are exceedingly significant in determining theavailability of nutrients in the soil. Protozoa are involved in themineralizing of nutrients, which make nutrients available for use byplants and other organisms.

Question7

Oribatida

Plants Organic Matter MesostigmatidaAnts Hen Man

Prostigmatida

Question8

Iagree with the statement since there are a variety of soil organisms,which cannot be exhausted. In most studies, people only learn about afew soil organisms this has helped in understanding the importanceof these soil organisms. Therefore, it is not a must for one to knowabout all soil organisms in order to understand the role of soilbiota in ecosystem function.

Question9

Althoughmicrobivorous nematodes have been found to account for approximately60-80% of the total nematodes, the microbivorous nematodes have beenrelatively little studied by scientists due to their littlesignificance to the ecosystem.

Question10

Twospecies of bacteria feeding nematodes are likely to co-occur in thesame habitat if they have the same respiratory rate, and theirmetabolic rates associated to temperature is the same. This iscritical since in case they engage in an activity, they can workwithin the temperature range. On the other hand, they may fail toco-occur if they work under different temperature range.

Question11

Antsand termites are both soil organisms, but have differences.Biologically, the two have differences in that termites belong to theorder Isoptera, while ants belong to the order Hymenoptera. On theother hand, termites eat plant tissues, while ants are scavangers.Furthermore, ants undergo a complete metamorphosis, while termitesundergo incomplete metamorphosis (Leadley,2008). Ants’ habitats are in the soil, wood, and cavities inplants. In the soil, they help inn turning and aerating the soil.However, their role in wood and plant cavities is destructive. On theother hand, the habitats for termites include soil, moist wood, andin plants. Just like ants, termites cause destruction in plants andwood and help in aerating soil.

Question12

Oneof the adaptations that help different species of oligochaetes tocoexist in the same soil volume is the ability to adapt in both moistand dry habitats (Chapman &ampReiss,2000). This is critical for soil processes since it helps them inaerating the soil, despite it being dry or moist. Another adaptationis that they can live in a wide range of temperatures. This is alsocritical for soil aeration in different temperature ranges (Giere,2009).

Question13

TrophicStructure

Allthe three subdivisions have a similar trophic structure, where thefirst trophic level comprises of plants, then secondary and tertiarytrophic level.

LitterDecomposition

Thethree subdivisions influence litter decomposition differently. In themarine subdivision, litter decomposition is through moisture andsalty water. The same case applies in mangrove subdivision, butmoisture is a key influence in litter decomposition. On the otherhand, terrestrial subdivision influences litter decomposition throughheat (Reddy,1995).

References

Chapman,J. L., &amp Reiss, M. J. (2000).&nbspEcology:Principles and applications.Cambridge [u.a.: Cambridge Univ. Press.

Giere,O. (2009).&nbspMeiobenthology:The microscopic motile fauna of aquatic sediments.Berlin: Springer.

Leadley,B. A. (2008).&nbspEcologyof soil organisms.London: Heinemann Educational.

Reddy,M. V. (1995).&nbspSoilorganisms and litter decomposition in the tropics.Boulder [u.a.: Westview Press.

Slade,S. (2007).&nbspThenitrogen cycle.New York: PowerKids Press.