Riparian wetlands may provide numerous ecosystem services, including water quality protection, food and fiber supply, wildlife habitat, and carbon sequestration. In recent years, riparian forests have received increased attention and funding for riparian forest restoration projects. Unfortunately, failures of riparian restoration efforts are likely due to mortality of planted trees. Tree mortality is commonly attributable to several factors, including selection of species that are not well suited to the wetland sites, inadequate planting densities, soil compaction associated with former agricultural activities, lack of microtopographic relief that allow small seedling to survive on wet sites, competition by herbaceous plants, and browse. Selection of well-suited species, dense planting and use of mechanical soil site preparations are all potential remedies to partially address success of wetland restoration plantings. Riparian restoration projects have historically been undertaken with goals of improving water quality and/or wildlife habitat, but in recent years there has been increased valuation of carbon sequestration. Carbon valuation appears to be increasing, but more research is needed to determine rates and pools of carbon accumulation in riparian areas. Our research quantifies forest establishment effects on multiple carbon pools in a densely planted, 12-year-old old-field riparian restoration. Our research evaluated the effects of four soil mechanical site preparations (bed, disk, pit, and mound and rip) and species selection (American sycamore (Platanus occidentalis) and willow oak, (Quercus phellos) on forest establishment and carbon storage across multiple pools, namely in planted trees, herbaceous vegetation, fine roots, organic soil horizons, and the mineral soil. At 12 years, we found that species selection was more important to carbon storage than site preparation. American sycamore was well suited to the site and had better survival than willow oak (64% vs 42% survival). American sycamore also stored more carbon across all site preparations than willow oak. Measured carbon storage averaged 74.8 Mg ha-1 for American sycamore treatments and 63.1 Mg ha-1 for willow oak treatments. The plots were densely planted (1.2 m (4ft) by 1.8 m (6ft) spacing), and forests were established even in higher mortality willow oak plots. These results indicate that high planting density is potentially a viable practice for establishing riparian forest cover, especially if desired species are marginally site suited or other survival inhibiting factors exist. / Master of Science / Riparian forests located within the floodplain of streams are known to protect stream water quality, provide wildlife habitat, and store carbon. Due to these benefits, trees may be replanted on riparian areas that were formerly used for agriculture. Unfortunately, trees planted on these restoration sites have often died. The tree mortality may be due to planting incorrect tree species that may struggle on wet floodplains, soil compaction from agricultural practices, not enough trees being planted, and restored floodplains lacking small, elevated areas common across natural wetlands known to favor tree rooting and survival. Reasonably, selecting species that are well suited to a specific site, planting trees more densely, and using plowing methods designed to break up compaction and create some relief in elevation would amend these issues. Traditionally, floodplain restorations have focused on improving water quality and providing habitat for wildlife, but the benefits of storing carbon have become increasingly valuable in recent years. While we know that wetlands store carbon, research is needed to examine how quickly and where carbon is stored. Our research quantifies forest establishment and carbon storage of very densely planted, 12-year-old American sycamore (Platanus occidentalis) and willow oak (Quercus phellos) plantations. This research examines the effects four soil tillage methods and tree species selection had on tree survival and carbon storage. Carbon storage was measured in vegetation, soil, and small roots. Twelve years after planting, species selection had a greater impact on carbon storage than soil tillage methods. No tillage method altered survival or total carbon after 12 years, but American sycamore was found to have better survival and more carbon than willow oak in all soil tillage treatments. Both species were successful in establishing planted forests on the floodplain, but the success was aided by the very high initial numbers of planted trees that ensured enough trees would survive on the site even after trees were lost to mortality. Creation of willow oak forests benefitted more from dense planting, as it was less suited to the site and more planted willow oaks died. We recommend tillage for compacted soil, selecting the most suitable tree species, and planting adequate numbers of trees.

The estimation of afforestation reservation prices for small landowners in New Zealand has not been the subject of much research despite its importance in predicting future land use. Reservation prices for planting represent the minimum payment a landowner must receive before converting land from agriculture to forest. A survey of 728 landowners from every region of New Zealand who own between 20 and 200 hectares of forest as well as other unplanted land used for agriculture were surveyed about forestland, forest land owner demographics, ownership objectives, silviculture and reservation prices. In this study, reservation price strategies were investigated by offering hypothetical annual and one-time payments for converting land from agriculture to forestry. From this survey, the average one-time payment a landowner would be willing to accept to convert a hectare of land from agriculture to forestry was $3,554 and the average annual payment to convert a hectare of land was $360. The key factors influencing the reservation price were; whether or not the landowner lived on the property, if one of the ownership objectives was income from carbon, the primary agricultural enterprise and total household income. An implied discount rate was calculated for each landowner and excluding those who would not accept any payment the average after-tax discount rate was 9.7%. Small landowners indicated that their primary reason for owning plantation forest was income from timber with very few landowners using their forest land for recreation. The median farm size was 400 hectares and the median forest plantation was 37 hectares. Planting of radiata pine peaked in 1994 and 1995 with more radiata pine planted in 1994 than in all the years from 2000-2009. Most landowners are performing some type of silviculture in their forests. Ninety percent of landowners are pruning in the current rotation while only 61% plan to prune in the future. Only 26% of landowners have engaged in any commercial harvesting in the past ten years but as their current rotation matures 71% plan to replant on the same site. A majority of respondents thought the situation for forest landowners was getting better. Understanding the reservation price strategies of landowners is important for predicting future land use patterns and recognizing how close landowners are to converting land. The ownership objectives of landowners and the replanting decisions they make are critical for future timber supply. The results of this study can assist in the development of forest establishment incentive programmes. Better information about landowner characteristics will result in enhanced decision-making for the timber industry and the government in New Zealand.