Ecosystem Services in a Transitional Forest Landscape: Shifting Trajectories in Southeast Michigan,USA

North American forests provide multiple ecosystem services, such as carbon storage, biodiversity, and recreation. These services are often coordinated through multifunctional management, whereby various users and owners contribute to collective agendas. Forests in exurban “transition” zones are crucial components in the sustainability of broader metropolitan landscapes, but represent a particularly understudied confluence of ecosystem services and multifunctional management. In this paper, we develop a place-based approach to assess ecosystem services in transitional forests (those between rural and urban). We demonstrate how trajectories of forest composition are linked with shifting ecosystem services that both shape and are shaped by management activities. Sited in Stinchfield Woods, a forest in southeast Michigan, this study draws on a household survey, interviews, ecological data, and archival information. Given variations in priorities over time and among different users, we suggest that coordinated, adaptive management may improve provisioning of ecosystem services in ways that benefit multiple users.     

Solitary Rossby Waves in Zonally Varying Jet Flows

The dynamics of solitary Rossby waves (SRWs) embedded in a meridionally sheared, zonally varying background flow are examined using a non-divergent barotropic model centered on a midlatitude g -plane. The zonally varying background flow, which is produced by an external potential vorticity (PV) forcing, yields a modified Korteweg-de Vries (K-dV) equation that governs the spatial-temporal evolution of a disturbance field that contains both Rossby wave packets and SRWs. The modified K-dV equation differs from the classical equation in that the zonally varying background flow, which varies on the same scale as the disturbance field, directly affects the disturbance linear translation speed and linear growth characteristics. In the limit of a locally parallel background flow, equations governing the amplitude and propagation characteristics of SRWs are derived analytically. These equations show, for example, that a sufficiently large (small) translation speed and/or a sufficiently weak (strong) background zonal shear favor transmission (reflection) of the SRW through (from) the jet. Conservation equations are derived showing that time changes in the domain averaged amplitude ("mass") or squared amplitude ("momentum") are due to zonal variation in both the linear, long-wave phase speed and linear growth; dispersion and nonlinearity do not affect the "mass" or "momentum". Provided (1) the background PV forcing is sufficiently small, or (2) the background PV forcing is meridionally symmetric and the disturbance is a SRW, the dynamics of the disturbance field is Hamiltonian and mass and energy are thus conserved. Numerical solutions of the K-dV equation show that the zonally varying background flow yields three general classes of behavior: reflection, transmission, or trapping. Within each class there exists SRWs and Rossby wave packets. SRWs that become trapped within the zonally localized jet region may exhibit the following behaviors: (1) an oscillatory decay to a steady state at the jet center, (2) the creation of additional SRWs within the jet region, or (3) a steady-state wherein the solution has a smoothed step-like structure located downstream along the jet axis.     

Origin of glacial ridges (OIS 6) in the Kaskaskia Sublobe,southwestern Illinois,USA

The origin of Illinois Episode (OIS 6) glacial ridges (formerly: ‘Ridged Drift’) in the Kaskaskia Basin of southwestern Illinois is controversial despite a century of research. Two studied ridges, containing mostly fluvial sand (OSL ages: ~ 150 ± 19 ka), with associated debris flows and high-angle reverse faults, are interpreted as ice-walled channels. A third studied ridge, containing mostly fine-grained till, is arcuate and morainal. The spatial arrangement of various ridge types can be explained by a glacial sublobe in the Kaskaskia Basin, with mainly fine-grained ridges along the sublobe margins and coarse-grained glaciofluvial ridges in a paleodrainage network within the sublobe interior. Illinois Episode till fabric and striation data demonstrate southwesterly ice flow that may diverge near the sublobe terminus. The sublobe likely formed as glacial ice thinned and receded from its maximum extent. The Kaskaskia Basin contains some of the best-preserved Illinois Episode constructional glacial landforms in the North American midcontinent. Such distinctive features probably result from ice flow and sedimentation into this former lowland, in addition to minimal postglacial erosion. Other similar OIS 6 glacial landforms may exist in association with previously unrecognized sublobes in the midcontinent, where paleo-lowlands might also have focused glacial sedimentation.     

Method‐dependent influence of environmental variables on reef fish assemblages when comparing trap and video surveys

Despite substantial survey effort and a large body of literature on abiotic and biotic factors in temperate reef ecosystems, knowledge of the complex and interactive effects of environmental variables on those communities is limited. Various survey methods have been developed to study environmental predictors of biodiversity, but there remains a gap in our understanding of how survey results are influenced by environmental factors. Here, we surveyed the fish assemblage associated with southeastern U.S. temperate marine reefs with simultaneous, paired trap, and camera gears throughout a ~50,000 km² area during 2011–2013 and assessed the influence of environmental variables on the trap‐ and video‐surveyed assemblages. Predictor variables in the multivariate general linear models included depth, temperature, month, year, location, substrate relief, percent sessile biota, biota type, and turbidity. Depth and latitude had the greatest influence on the fish assemblage for both gears. The influence of habitat variables differed between methods and percent biota explained more variation in the fish assemblage when assessed by traps, while substrate relief and biota type explained more variation in the fish assemblage when assessed by video. In general, habitat complexity was positively related to the abundance of fishes in the video survey, but there was a negative relationship in the trap survey. Differences between gears were species‐specific and the influences of environmental variables were similar for some species such as Haemulon plumierii and Hyporthodus niveatus. The methods presented here can be used to assess method‐dependent differences in fish assemblages, which is a necessary precursor to assess the effect of environmental variables on the accuracy of surveys.     

Palynology of Triassic–Jurassic boundary sections in northern Switzerland

A first palynostratigraphic scheme of Upper Triassic deposits in northern Switzerland was established based on spore-pollen associations and dinoflagellate cyst records from the upper part of the Upper Triassic Klettgau Formation and the lower part of the Lower Jurassic Staffelegg Formation. Drill cores from the Adlerberg region (Basel Tabular Jura) and from Weiach (northern part of Canton Zurich) as well as from an outcrop at the Chilchzimmersattel (Basel Folded Jura) were studied and five informal palynological associations are distinguished. These palynological associations correlate with palynological association of the Central European Epicontinental Basin and the Tethyan realm and provide a stratigraphic framework for the uppermost Triassic sediments in northern Switzerland. Throughout the uppermost Triassic to Jurassic palynological succession a remarkable prominence of Classopollis spp. is observed. Besides Classopollis spp. the three Rhaetian palynological associations A to C from the Upper Triassic Belchen Member include typical Rhaetian spore-pollen and dinoflagellate taxa (e.g., Rhaetipollis germanicus, Geopollis zwolinskae, Rhaetogonyaulax rhaetica, and Dapcodinium priscum). Association B differs from association A in a higher relative abundance of the sporomorph taxa Perinopollenites spp. and the consistent occurrence of Granuloperculatipollis rudis and Ricciisporites tuberculatus. Spore diversity is highest in the late Rhaetian palynological association C and includes Polypodiisporites polymicroforatus. A Rhaetian age for the Belchen Member is confirmed by palynological associations A–C, but there is no record of the latest Rhaetian and the earliest Jurassic. In contrast to the Rhaetian palynological associations the Early Jurassic associations W and D include Pinuspollenites spp., Trachysporites fuscus (in association W), and Ischyosporites variegatus. In the view of the end-Triassic mass extinction and contemporaneous environmental changes the described palynofloral succession represents the pre-extinction phase (associations A and B) including a distinct transgression, the extinction phase (association C) associated with a regression, and the post-extinction phase (association W).     

Neighborhood and socioeconomic change in emerging megapolitan nodes: tracking shifting social geographies in three rapidly growing United States metropolitan areas, 1980–2010

This paper investigates the complex demographic and social changes that have occurred in the neighborhoods of fast-growing United States metropolitan areas emerging as nodes in megapolitan regions between 1980 and 2010. A neighborhood typology is created using k-means cluster analysis to examine the demographic and housing characteristics, and geographic distribution, of neighborhoods that have existed in rapidly growing metropolitan areas. A socioeconomic index is created using principal component analysis (PCA) to analyze socioeconomic conditions within neighborhoods. Using data from the metropolitan areas of Las Vegas, Nevada; Austin, Texas; and Raleigh, North Carolina, this study identifies five neighborhood types, each of which has distinctive geographic and socioeconomic trends. The geographic orientation of each metropolitan area within their larger megapolitan region appears to have a role in the geography of neighborhood change. The results are also discussed in relation to human ecology, immigration, and economic restructuring.