The degradation of land formerly reclaimed after surface‐coal‐mining (opencast) is a widespread problem in upland Wales (UK). This community‐based project aims to support the voluntary sector in land reclamation by investigating the means of reversing land degradation. It explores ways of encouraging trees to ameliorate the severely compacted, infertile, mine‐soils typical of former opencast sites. This study evaluates the benefits of a single initial application of 2‐year slow release fertilizer (SRF), both with and without additional supplements, through a 10‐year controlled experiment in a mixed planting of common Alder (Alnus glutinosa (L.) Gaertn), Oak (Quercus petraea (Matt.) Liebl., Quercus robur L. and hybrids) supplemented with Scots Pine (Pinus sylvestris, L.); Silver Birch (Betula pendula, Roth); Goat Willow (Salix caprea, L.) and Rowan (Sorbus aucuparia, L.). After 10 years, SRF treatment resulted in a small, marginally significant, decrease in survival (85% vs. 83%) across all species, except Oak, but SRF‐treated trees were significantly larger than those given no‐SRF at planting (421 cm vs. 368 cm). By contrast, in Year 5 data, only SRF‐treated Alders are marginally significantly larger, whereas in Years 1–3 across all six species, significantly more records show greater mean growth in trees with no‐SRF than those given SRF at planting. Probably, this delayed response to SRF treatment resulted from the slow development of the larger soil ecosystem. Treatment with additional supplements (double SRF, remineralization agent and superphosphate) tended to have negative impacts on growth but double SRF and to a lesser degree remineralization had a positive effect on survival.

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Land degradation on officially ‘reclaimed’ opencast coal‐mine sites is a widespread problem in South Wales. This project explores methods suitable for use by community volunteers seeking to effect local environmental improvement by restoring geoecological self‐sustainability on lands that are commonly affected by extreme auto‐compaction and low soil nutrient status. This paper describes a formally established 7‐year experiment designed to assess the effect of three alternative tree planting strategies used in the forestation of such lands. These are notch planting (e.g. forestry), pit planting (e.g. parks and gardens) and trench planting (e.g. orchard terraces). The study explores tree survival and growth for two species commonly used in land reclamation contexts: alder [Alnus glutinosa (L.) Gaertn] and Welsh or Durmast Oak [Quercus petraea (Matt.) Liebl]. t‐testing of the results shows that survival and growth rates for both species tend to be significantly better for trench planting than for pit planting than for notch planting. Differences in mortality between pit‐planted and trench‐planted trees become less significant during the experiment while differences in growth increase with time. The conclusion is that providing a loosened, lower density, rooting substrate significantly improves both the growth and the survival rates of trees planted in compacted Welsh surface coal‐mine spoils and that trench planting is more effective than parks and gardens‐style pit planting, which is more effective than forestry‐style notch planting. Copyright © 2013 John Wiley & Sons, Ltd.

The United Kingdom has a problem in the disposal of municipal green waste (MGW). This is unsuitable for landfill, but when properly composted may be beneficial to tree growth. A formal controlled trial of the 11-year growth (height, diameter at breast height [DBH]) and survival of 3 tree species was evaluated on degraded former opencast coal land on the margins of UNESCO’s Blaenavon Industrial Landscape World Heritage site in South East Wales. Forest reclamation is considered a viable cost-effective approach to reclamation but success may be compromised by infertile and seriously compacted substrates, the depleted bio-geoecological system, and a lack of funding. In this trial, trees were (or were not) supplied, on planting, with 0.75 kg per stem of composted MGW – here a mixture of 40% domestic food waste and 60% garden waste. Results show that the application of MGW made no significant difference to either tree height or DBH. Survival rates were highest for Common Alder ( Alnus glutinosa (L.) Gaertn.) followed by Silver Birch ( Betula pendula, Roth) and European Larch ( Larix decidua Mill.). However, Silver Birch and Larch treated with MGW compost had significantly greater survival rates, whereas Alder had significantly lower survival rates, compared with trees planted without MGW treatment.

Many reclaimed opencast coal-lands in Wales are now seriously degraded. This study explores the 10-year growth of native trees planted on compacted coal spoil. It compares the relative benefits of planting with spent mushroom compost (SMC) or well-rotted farmyard manure (FYM), both with and without supplementary fertilizer. Four main tree species—Common Alder, Oak, Scots Pine and Silver Birch—are considered. The survival of SMC-planted trees (77%) was significantly higher than for FYM-planted (72%). In Year 10, SMC-planted trees were significantly taller than those planted with FYM (4.75 vs. 4.57 m, respectively). Similarly, basal diameter (measured above the root collar) was larger among the SMC-planted trees. Discriminant analysis showed that the key discriminating variable between SMC-planted and FYM-planted trees was the type of fertilizer applied during planting. Adding slow-release fertilizer (SRF) and SRF plus superphosphate (SRF + P2O5) was beneficial to FYM-planted trees. Fertilizer supplements often favor the growth of FYM-planted trees in the early years, but later SMC-planted trees take the lead. The only species that benefited long term from FYM or fertilizer supplements was Alder. Overall, SMC-planted trees perform better than FYM-planted trees, but some of the difference can be mitigated by supplementary fertilization. Overall, SMC-planted trees perform better than FYM-planted trees.