A general framework for quantifying the effects of land-use history on ecosystem dynamics

Land-use legacies are important for explaining present-day ecological patterns and processes. However, an overarching approach to quantify land-use history effects on ecosystem properties is lacking, mainly due to the scarcity of high-quality, complete and detailed data on past land use. We propose a general framework for quantifying the effects of land-use history on ecosystem properties, which is applicable (i) to different ecological processes in various ecosystem types and across trophic levels; and (ii) when historical data are incomplete or of variable quality. The conceptual foundation of our framework is that past land use affects current (and future) ecosystem properties through altering the past values of resources and conditions that are the driving variables of ecosystem responses. We describe and illustrate how Markov chains can be applied to derive past time series of driving variables, and how these time series can be used to improve our understanding of present-day ecosystem properties. We present our framework in a stepwise manner, elucidating its general nature. We illustrate its application through a case study on the importance of past light levels for the contemporary understorey composition of temperate deciduous forest. We found that the understorey shows legacies of past forest management: high past light availability lead to a low proportion of typical forest species in the understorey. Our framework can be a useful tool for quantifying the effect of past land use on ecological patterns and processes and enhancing our understanding of ecosystem dynamics by including legacy effects which have often been ignored

High-resolution palynology reveals the land-use history of a Sami renvall in northern Sweden

Acknowledgements: This research was funded by the Leverhulme Trust through the Footprints on the Edge of Thule project, and was written under the auspices of the ERC-funded project Arctic Domus. Thanks are offered to Audrey Innes for laboratory assistance; Ian Foster for 210Pb dating; Gordon Cook for AMS radiocarbon analyses; and Martin Konert and the late Sjoerd Bohncke for assistance with LOI and related analyses. The comments of Tim Mighall, Jeff Blackford, Mari Kuoppamaa, two anonymous referees and the editor helped to improve the paper.Peer reviewedPublisher PD

Former land use affects the nitrogen and phosphorus concentrations and biomass of forest herbs

The colonization rates of understorey plants into forests growing on former agricultural land differ remarkably among species. Different dispersal and recruitment largely account for the contrasting colonization rates, but different effects of the soil legacies of former agricultural land use on plant performance may also play a role. Seven herbaceous forest species were sampled in paired post-agricultural and ancient forest stands to study whether land-use history has an effect on the aboveground nutrient concentrations (N, P and N:P ratios) and biomass of forest herbs and, if so, whether slow and fast colonizing species respond differently. Results showed that P concentrations were significantly affected by former land use with higher concentrations in the post-agricultural stands. N concentrations were unaffected and N:P ratios were significantly higher in the ancient stands. Nutrient concentrations varied considerably among species, but the variation was unrelated to their colonization capacity. Six out of the seven species had higher biomass in the post-agricultural stands relative to the ancient stands, and the degree to which the species increased biomass was positively related to their colonization capacity, i.e., the fast colonizing species showed the strongest increase. Such differential responses to past land use may contribute to the contrasting colonization capacity of forest plants. Land-use history thus affected both the nutrient concentrations and biomass of forest herbs, and only the biomass response was related to colonization capacity

Copper and zinc as a window to past agricultural land-use.

Abstract Intensive agricultural management significantly affects soil chemical properties. Such impacts, depending on the intensity of agronomic practices, might persist for several decades. We tested how current soil properties, especially heavy metal concentrations, reflect the land-use history over a 24,000 ha area dominated by intensive apple orchards and viticulture (South Tyrol, ITA). We combined georeferenced soil analyses with land-use maps from 1850 to 2010 in a space-for-time approach to detect the accumulation rates of copper and zinc and understand how present-day soil heavy metal concentrations reflect land-use history. Soils under vineyards since the 1850s showed the highest available copper concentration (median of 314.0 mg kg-1, accumulation rate between 19.4 and 41.3 mg kg-1·10 y-1). Zinc reached the highest concentration in the same land-use type (median of 32.5 mg kg-1, accumulation rate between 1.8 and 4.4 mg kg-1·10 y-1). Using a random forest approach on 44,132 soil samples, we extrapolated land-use history on the permanent crop area of the region, reaching an accuracy of 0.72. This suggests that combining current soil analysis, historical management information, and machine learning models provides a valuable tool to predict land-use history and understand management legacies

Role of plant functional traits in determining vegetation composition of abandoned grazing land in north-eastern Victoria, Australia

Question: In the Northern Hemisphere, species with dispersal limitations are typically absent from secondary forests. In Australia, little is known about dispersal mechanisms and other traits that drive species composition within post-agricultural, secondary forest. We asked whether mode of seed dispersal, nutrient uptake strategy, fire response, and life form in extant vegetation differ according to land-use history. We also asked whether functional traits of Australian species that confer tolerance to grazing and re-colonisation potential differ from those in the Northern Hemisphere. Location: Delatite Peninsula, NE Victoria, Australia. Methods: The vegetation of primary and secondary forests was surveyed using a paired-plot design. Eight traits were measured for all species recorded. ANOSIM tests and Non-metric Multi-dimensional Scaling were used to test differences in the abundance of plant attributes between land-use types. Results: Land-use history had a significant effect on vegetation composition. Specific leaf area (SLA) proved to be the best predictor of response to land-use change. Primary forest species were typically myrmecochorous phanerophytes with low SLA. In the secondary forest, species were typically therophytes with epizoochorous dispersal and high SLA. Conclusions: The attributes of species in secondary forests provide tolerance to grazing suggesting that disturbance caused by past grazing activity determined the composition of these forests. Myrmecochores were rare in secondary forests, suggesting that species had failed to re-colonise due to dispersal limitations. Functional traits that resulted in species loss through disturbance and prevented re-colonisation were different to those in the Northern Hemisphere and were attributable to the sclerophyllous nature of the primary forest

Biomarkers as Proxies to Analyse Land-Use History in Northern Jordan

In the semi-arid 'Decapolis region' in northern Jordan, due severe land degradation in the past, 'barren' and 'impoverished' landscapes can be found today. It is widely believed that land degradation in these regions was caused by ancient land use, e.g. overgrazing due to ‘Arab mismanagement'. However, the connection of degradation with land use is far from certain. The 'Decapolis region' is located in an approximately 100 km wide transition zone from Mediterranean to steppe and desert climate. Therefore, the landscape in this region is highly sensitive to climate variations. A major sedimentation phase in the late 6th century AD appears to represent a significant climate change towards more aridity, and might be connected with a cluster of heavy rainfall events in northern Jordan. In fact, more recent studies have found that periods of predominantly pastoral land use in northern Jordan were connected with natural reforestation. Since a dating of sedimentation alone does not deliver clues about the precise reason of deposition, a multidisciplinary team is analyzing the land-use history in the ‘Decapolis’ region. This presentation focusses on ongoing biomarker analyses. Samples were selected considering geoarchaeological data, including phosphorus concentrations, archaeological data, including distribution of potsherds and other fragments on ancient fields and data of further disciplines. Vegetation changes are investigated by analyses of n-alkanes and terpenoids. Manuring with faeces is analysed by specific steroids that are indicative for faeces deposition. Preliminary results showed a high input of omnivorous (pigs, humans) faeces in some areas. Manuring with faeces of herbivores seemed to be less important

Holocene Vegetation and Land Use History in the Northern Vosges (France)

A radiocarbon-dated peat profile from Rond Pertuis supérieure mire in the uplands of the Northern Vosges is studied using palynological methods. The profile dates from the middle Atlantic period (4500–3100 B.C.) to recent times. During the middle of the Atlantic period an oak forest rich in pine covered the Northern Vosges. Fir and beech immigrated at the end of the Atlantic leading to the decline of oak and pine in the forest. This also marked the onset of decisive human influence on the development of the terrestrial vegetation. Five land use phases were detected, the first one at the end of the Neolithic period (~4000–2200 B.C.). Subsequently, continuous land use is evident from the Bronze Age (2200–800 B.C.) up to now. In the late Middle Ages (A.D. 900–1500) and the early Modern Era (since A.D. 1500), the woodlands were completely altered by human activities. During the 19th century modern forestry introduced spruce into the investigated area in the Northern Vosges. Spruce afforestation then accelerated in the middle of the 20th century.researc

Interactive effects of past land use and recent forest management on the understorey community in temperate oak forests in South Sweden

Questions: Past agricultural land use and forest management have shaped and influenced the understorey composition in European forests for centuries. We investigated whether understorey vegetation assemblages are affected by (a) legacies from a historical infield/outland agricultural system (i.e., a system with nutrient-enriched vs nutrient-depleted areas), (b) recent management intensity (i.e., thinning/felling activities), and (c) the interaction of recent management and potential legacies. Location: Oak forests in Skane, south Sweden. Methods: We use three vegetation surveys (1983, 1993/94 and 2014) and notes on management and land-use history, available for 62 permanent 500 m(2) plots. We conducted linear mixed effect modelling to detect both main and interactive effects of past land use and recent management on understorey diversity measures and vegetation indicator values for light and fertility. We combined nonmetric multidimensional scaling with permutational multivariate analysis of variance and indicator species analysis to detect compositional differences caused by past land use and/or recent management. Results: Understorey diversity was mainly affected by management activities, but the former infield/outland agricultural system was an important determinant of understorey composition. Understorey composition of former infields reflected higher nutrient availability and lower light availability compared to former outland. Past land use and recent management had interactive effects on light-related understorey variables: for the less intensively managed plots, the outland plots contained more light-demanding species than the infield plots, while for the more intensively managed plots, the light-demanding signature of the understorey was similar for infield and outland plots. Conclusions: Different intensities of past land use as well as recent forest management influenced the composition of the forest understorey, and interactions were present. Therefore, careful consideration of both the long-term land-use history and the more recent disturbances due to forest management are necessary when making future predictions of understorey composition and diversity