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The present study has investigated the occurrence of the English anaphoric expressions, he/she, in L2 grammars. Adult Chinese learners of English were evaluated on whether they were able to provide a correct semantic interpretation of these pronouns when they appeared in complex sentences (subordinate + matrix) and correlative structures. Results have shown that L2 learners did not encounter any major difficulties in identifying the appropriate antecedents of these pronominal forms and were almost as accurate as English native speakers. This positive acquisition scenario clearly indicates that a correct reference production of English anaphors is attainable despite the visible differences between the two languages. Theoretically, it seems to support some form of Continuity in SLA; it is also consistent with the idea that internal interface phenomena are fully acquirable and are not subject to fossilization ("Interface Theory," Sorace in Biling Lang Cogn 7:143-145, 2004; Linguist Approaches Biling 1:1-33, 2011). Furthermore, L2 structures partially present in L1 grammar are attainable without necessarily relying on learners' first language (contra "Failed Functional Features Hypothesis," Hawkins and Chan in Second Lang Res 13:187-226, 1997). In fact, contrary to previous L2 studies, no visible L1 transfer effects were observed in the data.

Satellite-based estimation of forest variables including forest biomass relies on model-based approaches since forest biomass cannot be directly measured from space. Such models require ground reference data to adapt to the local forest structure and acquired satellite data. For wide-area mapping, such reference data are too sparse to train the biomass retrieval model and approaches for calibrating that are independent from training data are sought. In this study, we compare the performance of one such calibration approach with the traditional regression modelling using reference measurements. The performance was evaluated at four sites representative of the major forest biomes in Europe focusing on growing stock volume (GSV) prediction from time series of C-band Sentinel-1 and Advanced Land Observing Satellite Phased Array L-band Synthetic Aperture Radar (ALOS-2 PALSAR-2) backscatter measurements. The retrieval model was based on a Water Cloud Model (WCM) and integrated two forest structural functions. The WCM trained with plot inventory GSV values or calibrated with the aid of auxiliary data products correctly reproduced the trend between SAR backscatter and GSV measurements across all sites. The WCM-predicted backscatter was within the range of measurements for a given GSV level with average model residuals being smaller than the range of the observations. The accuracy of the GSV estimated with the calibrated WCM was close to the accuracy obtained with the trained WCM. The difference in terms of root mean square error (RMSE) was less than 5% units. This study demonstrates that it is possible to predict biomass without providing reference measurements for model training provided that the modelling scheme is physically based and the calibration is well set and understood. [ABSTRACT FROM AUTHOR]

In this paper, I investigate the phenomenon of morphological variability in the production of Italian determiners, descriptive adjectives, and direct object pronouns by adult English learners of Italian to determine whether morphological errors are the result of computational or representational difficulties. Second language acquisitionists do seem to agree on whether erroneous morphological forms noticeable even in advanced second language grammars due to the absence of the functional apparatus responsible for their feature-checking, a partially developed morphological competence, or even learners' performance limitations. Data have shown that the morphological features of Italian Determiner Phrases (DPs) and pronouns are fully acquirable, despite their absence in the grammar of learners' native language. Furthermore, adult English speakers' precocious familiarity with Italian nominal and pronominal morphology, and the uniform occurrence of erroneous forms in their interlanguage grammars suggest that morphological variability does not stem from the absence of the necessary functional structure, but from a general deficiency in properly "assembling" the morphological features of a particular lexical item, and learners' inability to map them with the syntactic information available. (Contains 7 tables and 2 footnotes.)

The response of the terrestrial carbon cycle to climate change is among the largest uncertainties affecting future climate change projections. The feedback between the terrestrial carbon cycle and climate is partly determined by changes in the turnover time of carbon in land ecosystems, which in turn is an ecosystem property that emerges from the interplay between climate, soil and vegetation type. Here we present a global, spatially explicit and observation-based assessment of whole-ecosystem carbon turnover times that combines new estimates of vegetation and soil organic carbon stocks and fluxes. We find that the overall mean global carbon turnover time is 23(+7)(-4) years (95 per cent confidence interval). On average, carbon resides in the vegetation and soil near the Equator for a shorter time than at latitudes north of 75° north (mean turnover times of 15 and 255 years, respectively). We identify a clear dependence of the turnover time on temperature, as expected from our present understanding of temperature controls on ecosystem dynamics. Surprisingly, our analysis also reveals a similarly strong association between turnover time and precipitation. Moreover, we find that the ecosystem carbon turnover times simulated by state-of-the-art coupled climate/carbon-cycle models vary widely and that numerical simulations, on average, tend to underestimate the global carbon turnover time by 36 per cent. The models show stronger spatial relationships with temperature than do observation-based estimates, but generally do not reproduce the strong relationships with precipitation and predict faster carbon turnover in many semi-arid regions. Our findings suggest that future climate/carbon-cycle feedbacks may depend more strongly on changes in the hydrological cycle than is expected at present and is considered in Earth system models.

This experimental study investigates the acquisition of Italian accusative and dative clitics by English adult speakers. These pronouns are non-existent in English. Results from a grammaticality judgement task show that Italian accusative and dative clitics develop slowly but gradually in Italian second language (L2) grammars. Interestingly, the placement properties appear to develop earlier than their case properties. The possible implications of these findings for theories of the L2 initial state are considered. (Contains 2 figures and 6 tables.)