Reasoning about ecosystems includes consideration of causality over temporal and spatial distances; yet learners typically focus on immediate time frames and local contexts. Teaching students to reason beyond these boundaries has met with some success based upon tests that cue students to the types of reasoning required. Virtual worlds offer an opportunity to assess what students actually do in a simulated context. Beyond this, mobile devices make it possible to scaffold and assess learning in the real world. Situating learning outside, in the target contexts, bypasses many of the challenges of transfer. A study investigated the learning of fifth and sixth graders (n = 38) while they used a virtual world called EcoMUVE, designed to support learning of ecosystems concepts and complex causal dynamics, and mobile broadband device (MBDs) components, designed to assess and support learning and transfer in a real pond ecosystem. The experiences of two classes were contrasted as reference populations; one class participated in the MBD experience first, followed by the learning components in EcoMUVE; the other participated in EcoMUVE first, followed by the MBD components. Rich and triangulated data was collected to illuminate how students experienced and responded to the curriculum components. Both classes made learning gains in EcoMUVE. Students who completed EcoMUVE prior to their MBD experience transferred concepts to their pond explorations. Both classes made learning gains at the pond following the MBD support and revealed more expert reasoning about the importance of change over time and distant drivers in ecosystem dynamics.