In dendritic river systems, gene flow is expected to occur primarily within watersheds. Yet, rare cross‐watershed transfers can also occur, whether mediated by (often historical) geological events or (often contemporary) human activities. We explored these events and their potential evolutionary consequences by analyzing patterns of neutral genetic variation (microsatellites) and adaptive phenotypic variation (male color) in wild guppies ( Poecilia reticulata ) distributed across two watersheds in northern Trinidad. We found the expected signatures of within‐watershed gene flow; yet we also inferred at least two instances of cross‐watershed gene flow—one in the upstream reaches and one further downstream. The upstream cross‐watershed event appears to be very recent (41 ± 13 years), suggesting dispersal via recent flooding or undocumented human‐mediated transport. The downstream cross‐watershed event appears to be considerably older (577 ± 265 years), suggesting a role for rare geological or climatological events. Alongside these strong signatures of both contemporary and historical gene flow, we found little evidence of impacts on presumably adaptive phenotypic differentiation, except perhaps in the one instance of very recent cross‐watershed gene flow. Selection in this system seems to overpower gene flow—at least on the spatiotemporal scales investigated here.

Cemeteries existing within cities are often omitted from the “green space” narrative despite their high levels of vegetation. Given the relatively small areas of green space in many cities, it is important to appropriately manage these landscapes to ensure that residents can access green spaces and enjoy the many benefits they offer. The purpose of our paper is to demonstrate that cemeteries should be managed and researched as urban green spaces that provide ecosystem services. We compared and contrasted cemeteries with urban parks and used their similarities and differences, as well as a review of existing cemetery and other green-space literature, to discuss how cemeteries can provide a wide variety of ecosystem services. We found that cemeteries and parks both have high levels of vegetation, similar perceived safety issues, and some common rules and regulations, while differing in their consideration as public spaces, effect on real-estate values, historical–cultural value, and funding and management goals. Despite the differences, we believe that the vegetation (particularly trees), monuments, other infrastructure, and atmosphere within cemeteries make them well-suited to providing ecosystem services such as recreation, human health and restoration, stormwater management, microclimate regulation, aesthetics, and so on. Cemeteries can also potentially provide ecosystem “disservices” such as allergens, invasive/dangerous/poisonous species, and the degradation of groundwater quality. However, we believe that the potential for ecosystem services far outweighs the potential for ecosystem disservices in urban cemeteries, and as such we believe they should be studied and managed as green spaces with functions beyond those of interment and mourning. Given the general superiority of trees over other vegetation in providing a diversity of ecosystem services, we urge cemetery managers to consider options for increases and improvements in cemetery tree populations.

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This systematic literature review identifies and critiques methodological trends in green gentrification research (focusing on studies of vegetative greening) and provides suggestions for advancing this field. Findings reveal (1) research has largely focused on U.S. case studies; (2) early work employed qualitative methods but quantitative analyses have become more common; (3) little attention has been paid to the influence of greening characteristics/functions and non-greening factors on gentrification; (4) the mechanisms through which greening leads to gentrification are not well understood, particularly on the demand side; and (5) despite being the main concern of green gentrification, displacement has not been well-documented.

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