Effects of initial planting method on the performance of mixed plantings of alder and oak on compacted opencast coal-spoils, Wales: 10-year results

Reed²,

D’Aucourt³

et al. 2018

Land Degrad Dev

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.

Section: Introductionmentioning

confidence: 99%

mentioning

confidence: 99%

Effects of initial fertilizer treatment on the 10‐year growth of mixed woodland on compacted surface‐coal‐mine spoils, S. Wales

Reed²,

D’Aucourt³

et al. 2018

Land Degrad Dev

“…The exception is Mn, where the trend is reversed. In theory, of course, the total uptake of trees increases with age because of their greater biomass (Haigh et al, 2018;Plamping et al, 2017). Table 6 displays correlations between the metal loadings in soils and leaves across the full range of plantings.…”

Section: Resultsmentioning

confidence: 99%

“…Here, Noustorova et al (1999) recorded a total microflora of 196-286*10 3 g, of which >80% were ammonifying bacteria. Earthworm biomass is also greater under Varteg's trees than outside the plantations (Plamping et al, 2017). The reduction of soil metal loadings is a system process; many organisms may be involved.…”

Section: Belgiummentioning

confidence: 99%

Phytoremediation: Metal decontamination of soils after the sequential forestation of former opencast coal land

Desai

Science of The Total Environment

Walkington

2019

Forest phytoremediation through forestry may be an effective means for reducing the metal loading in lands reclaimed after surface-coal-mining in the UK. Planted with mixed woodland, soil loadings of 5 key metals (Zn, Cd, Mn, Pb and Cu) decreased, significantly and progressively, compared to soils left as grassland, through a 14 year forestation chronosequence on land reclaimed from the former Varteg opencast coalmine, South Wales, UK. Fourteen years after initial tree planting, soil metal loadings decreased by 52% for Cd (4.3 mg.kg-1 per year), 48% for Cu (2.1 mg.kg-1 per year), 47% for Zn (7.3 mg.kg-1 per year), 44% for Pb. (7.1 mg.kg-1 per year) and 35% for Mn (45 mg.kg-1 per year). Analysis of metal loadings in the leaves of Alnus glutinosa (L. Gaertn) (Common Alder) and Betula pendula (Roth) (Silver Birch) found both species involved in metal uptake with birch taking up more Cd, Cu, Zn and Mn and Alder taking up more Pb. Concentrations of Zn, Mn and Cd (Birch only) increased significantly in leaves from, but not soils under, older plantings. Since different tree species take up metals at different rates, mixed plantings may be more effective in forest phytoremediation.

“…Since 1990, this has involved mixed plantings of native broad-leaved species, mainly Common Alder, Oak, and Scots Pine, with some Silver Birch, Rowan, and Goat Willow, using a variety of fertilisers, planting regimes, and subsequent records of tree growth. 33,37 The 2007 (MD07) planting differs from the earlier plantings on the Varteg site in using mono-specific blocks of trees, which reduces potential problems from allelopathy. It also introduces European Larch (Larix decidua Mill.)…”

Section: Selection Criteria For Tree Speciesmentioning

confidence: 99%

Composted Municipal Green Waste Enhances Tree Success in Opencast Coal Land Reclamation in Wales

Air, Soil and Water Research

Desai

Cullis

et al. 2019

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.