Prepositional Phrases as Nominal Postmodifiers

Although PPs have declined in use in science writing in the last decades (Biber & Gray, 2016), their functions as nominal postmodifiers are essential in science writing. One of the most widely used PPs is of-phrases. In addition to of-phrases, in, for, on, and with function as nominal post modifiers in science discourse. Similar to the role of prenominal modifiers, PPs enable the packing of meaning in a compact yet less explicit way as explained in the section where nouns as nominal modifiers were placed. The normed rates of occurrences for of-phrases reported in Table 4.6 indicate that their use does not differ between the registers. Despite a significant difference across the disciplines, the actual difference is not large. The corpus analysis showed that there is some degree of variation in the use of PPs as noun postmodifiers. For example, some PPs are simple, such as “the use of natural seed treatment,” or “the degree of anxiety.” However, some PPs show higher complexity through more embedding. For example, the sentence “the thermal analysis is followed by the development of structural FE models for the investigation of the structural response of the welded material (imse-ra-018)” shows that more than one PPs can be used in an embedded manner.

With the help of PPs as nominal post-modifiers, it is easy to expand the nominal group because with each preposition it is possible to lengthen the phrase. This extensive embedding function of PPs has been previously pointed out by Halliday and Martin (1993) and Halliday (2009), who argued that scientific language utilizes PPs extensively as they allow for the packing of large amounts of meaning into a compact whole, supplying a substantial meaning potential. The following list of examples from the corpus data provides examples showing how extensive phrasal embedding is made possible by the use of PPs.

• Considering both the investment and operational decision making, a mixed integer bi- level program model for capacity expansion in the integrated supply network for an electricity market was developed. (imse-ths-010)

• The increase in data and the advances in analytics have given companies the power to make more accurate predictions and classifications, leading to better solutions (imse-ths- 015)

• A considerable number of studies have tended to equate the provision of feedback on learners' writing with EC (apling-ra-014)

• The collected data could be used for or influence the development of a later study with a specific focus on register (apling-ths-001)

• Analyses of demographic transitions of wild-proso millet illustrated the overriding effect of seed production in sweet corn on subsequent spring seedling recruitment and yield loss in a rotation crop. (agron-ra-028)

• Time series of hourly values and daily mean values indicate that Agro-IBIS is able to capture the variability in soil moisture at multiple depths across the field. (agron-ths- 018)

• We evaluated the effects of cropping sequence and N fertilization on dryland soil temperature and water content at the 0-to-15 cm depth and surface co2, and CH4 fluxes in a Williams loam in eastern Montana. (agron-ra-012)

The prevalent use of PPs across the three disciplines and between the registers corroborates the developmental nature of grammatical complexity from coordination to

subordination, and to phrasal embedding suggested by earlier studies (e.g., Halliday, 1993b; Halliday & Matthiessen, 1999; Norris & Ortega, 2009). As Halliday (1993b) proposed, GM is the end of the language development continuum. According to Biber et al. (2011), the last phase of the language development progression is achieved by the use of higher number of nouns and noun phrases. Likewise, Halliday attributes the formation of GM to the heavy use of nominal groups and nominalizations. Considering these two similar perspectives, the results for the use of phrasal embedding seem consistent with the literature.

Lastly, the following excerpt from an agronomy research article represents the heavy reliance on nouns and noun phrase constituents in science research writing.

Quantifying global carbon and water balances requires accurate estimation OF gross primary production (GPP) and evapotranspiration (ET), respectively, across space and time. Models that are based on the theory OF light use efficiency (LUE) and water use efficiency (WUE) have emerged as efficient methods FOR predicting GPP and ET, respectively. Currently, LUE and WUE estimates are obtained from biome-specific look-up tables and coarse resolution remote sensing data WITH large uncertainties. The major objective OF this study was to parameterize eddy covariance tower-based ecosystem LUE (ELUEEC), defined as the ratio OF tower- based GPP (GPPEC ) to photosynthetically active radiation (PAR), and ecosystem WUE (EWUEEC ), defined as the ratio OF GPPEC to tower-based ET (ETEC ), using the Moderate Resolution Imaging Spectroradiometer (MODIS)-derived enhanced vegetation index (EVI) FOR predicting maize (Zea mays L.) GPP and ET, respectively. (agron-ra-017)

Note: Nouns are bolded; noun-noun sequences are bold underlined; adjectives are in italics; PPs as nominal postmodifiers are UNDERLINED CAPS; compounds are underlined italic

As the analysis of the text sample from agronomy shows, nouns are widespread in a specialist science discipline such as agronomy. The text speaks for itself, but the following

points are worth stressing again to remind the readers the nominal discourse style of the written academic language and science discourse.

✓ Nouns are pervasive in science discourse.

✓ Nouns can premodify a head noun with multiple noun + noun sequences (e.g., water use efficiency).

✓ Adjectives can premodify nouns (e.g., accurate estimation, major objective) and more than one adjective may precede nouns (e.g., gross primary production).

✓ Noun-participle compound can modify nouns (e.g., tower-based ecosystem, MODIS-derived enhanced vegetation index).

✓ Acronyms are widely used for nouns (e.g., LUE and WUE estimates)

✓ Prepositional phrases can postmodify nouns (e.g., methods for predicting maize) ✓ Noun phrases can be jointly pre- and post-modified (e.g., accurate estimation of

gross primary production and evapotranspiration; efficient methods for predicting GPP).

✓ Noun phrases can be extensively modified through phrasal embedding (e.g., using the Moderate Resolution Imaging Spectoradiameter (MODIS)-derived enhanced vegetation index for predicting maize).

As the last point supports very well, the nominal group is a powerful resource for meaning- making in the construal of science discourse. As noted by Halliday (1998), it “expands lexically, by the device known as modification: one noun functions as a kind of keyword, and other words are organized around it, having different functions with respect to this head noun” (p. 196). As a result, the nominal elements in the clause take over the semantic content and help the writers express science in more “synoptic” forms as opposed to the

more dynamic style of everyday communication mostly represented by the heavy use of verbs and clausal structures (Norris & Ortega, 2009, p. 563).