Exotic Plantations Research Articles

Habitat complementarity and butterfly traits are essential considerations when mitigating the effects of exotic plantation forestry

Habitat complementarity and butterfly traits are essential considerations when mitigating the effects of exotic plantation forestry

LAND USE CHANGES AND FLORAL DIVERSITY IN KENYA’S MT. ELGON FOREST ECOSYSTEM

<p><strong>Background</strong>. Montane forests encompass spectacular landscapes, a wide variety of ecosystems, a great diversity of species, and distinctive human communities. Mountain forests support about one quarter of world’s terrestrial biodiversity and include nearly half of the world’s biodiversity “hotspots.<strong> </strong>Understanding of land use change (LUC) in mountain forest ecosystem is crucial for sustainable management of the ecosystem especially in developing countries like Kenya where the majority of the people depend on natural resources for their livelihoods. Changes in land use in this forest ecosystem could lead to a decline in biodiversity and in the livelihoods of the forest adjacent communities. <strong>Objective:</strong> To evaluate the differences in land use changes and floral diversity of Mt. Elgon forest ecosystem. <strong>Methodology:</strong> Differences in land use changes on floral diversity were evaluated using quadrats that were placed in different land uses to measure species diversity and abundance. The Shannon-Weiner diversity index and Whittaker beta diversity index was used to determine changes and similarities in floral diversity, while Kruskal-Wallis test and chi square test was used to determine differences in species abundances. <strong>Result:</strong> This study established that there were differences in floral diversity in relations to land use changes. The Shannon-Weiner diversity index revealed that control (natural forest) site had the highest species diversity (H=2.07331, evenness=0.884), followed by indigenous plantations (H=1.93962; evenness 0.69957), urban settlements (H=1.85081; evenness=0.66754), Nyayo Tea Zone (H=1.5324, evenness=0.56), mixed farming (H=1.43694, evenness=0.43694) and exotic plantation (H=1.28231, evenness=0.61612). Whittaker beta diversity index for control site verses urban settlements was (0.5385), indigenous plantations (0.2222), Nyayo Tea Zone (0.1429) while mixed farming and exotic plantations (0.000). Kruskal-Wallis test revealed a statistically significant differences in total number of plant species in the various study sites (H=8.288; P=0.049). Similarly, the results revealed a significant difference between specific plant communities (trees, shrubs, herbs, ferns, and climbers) in the study area (H=38.116; P=0.000). Chi square test of homogeneity was used to test difference in distribution of species communities in different location and the results revealed that the differences were insignificant. <strong>Implications:</strong> Results of species diversity analyses show differences in floral diversity and similarities in areas under different land uses. <strong>Conclusion</strong>: There are significant differences in floral diversity in areas under different land uses of Mt. Elgon forest ecosystem. Species diversity and similarity of indigenous planted forests and urban settlement closely approach that of the natural forests. Floral diversity play a critical role in provisioning of essential ecosystem services.</p>

A Stand-Level Comparison of Carbon and Nitrogen Distribution in an Exotic Japanese Cedar Plantation and a Natural Oak Stand

This study compared carbon (C) and nitrogen (N) distribution at a stand level in an exotic Japanese cedar (Cryptomeria japonica D. Don) plantation and a natural Serrata oak (Quercus serrata Murray) stand growing under similar site conditions in South Korea. The aboveground biomass (stems, branches, and leaves) of 20 trees (10 of each species), the forest floor, and the mineral soils to a depth of 30 cm were sampled to determine C and N concentrations. Except in branches, C concentrations were significantly higher (p < 0.05) in the Japanese cedar plantation than in the Serrata oak stand, whereas N concentrations, except in the stem bark, were significantly lower in the Japanese cedar plantation. Reforestation with an exotic coniferous species significantly increased the C stocks in the aboveground biomass and the N stocks in the forest floor and mineral soils compared with a natural oak stand. The N stocks in the aboveground biomass were dependent on either the N concentrations or the C stocks in the tree components, whereas soil C and N stocks were negatively related to soil fertility parameters such as C/N ratio. Although it is uncertain which factors are responsible for the difference in aboveground C and soil N stocks following the establishment of Japanese cedar plantations on former natural Serrata oak stands, tree replacement may have an impact on C and N allocation within different forest compartments.

Leaf Thermal and Chemical Properties as Natural Drivers of Plant Flammability of Native and Exotic Tree Species of the Valparaíso Region, Chile.

Forest fires are one of the main environmental threats in Chile. Fires in this Mediterranean climate region frequently affect native forests and exotic plantations, including in several cases urban and rural settlements. Considering the scarcity of information regarding the fire response dynamics of tree species that are frequently affected by fires, this study aims to establish a flammability classification according to the evolution of the fire initiation risk presented by the most affected forest species in the Valparaíso region. Three exotic species, Eucalyptus globulus, Pinus radiata, and Acacia dealbata, and two native species, Cryptocarya alba and Quillaja saponaria, were studied. Flammability assays indicate that E. globulus, A. dealbata, and C. alba are extremely flammable, whereas P. radiata and Q. saponaria are flammable. Furthermore, E. globulus and A. dealbata have the highest heating values while Q. saponaria has the lowest values. The extreme flammability of E. globulus, A. dealbata, and C. alba indicates a high susceptibility to ignite. Furthermore, the high heat of combustion of E. globulus and A. dealbata can be associated with a high energy release, increasing the risk of fires spreading. In contrast, Q. saponaria has the lowest predisposition to ignite and capacity to release heat. Accordingly, this work shows that all studied tree species contain organic metabolites that are potentially flammable (sesquiterpenes, aliphatic hydrocarbons, alcohol esters, ketones, diterpenes, and triterpenes) and can be considered as drivers of flammability in vegetation. Finally, these preliminary results will aid in the construction of more resilient landscapes in the near future.

Effects of exotic plantation expansion and management intervention on woody plant species diversity, regeneration and soil seed bank in Tarmaber district, Ethiopia

This study was carried out to determine the effect of plantation forest with management intervention on woody plant species diversity in Tarmaber district north shewa zone Ethiopia, regeneration and soil seed bank species composition in five different forest types. A total of 75 circular sample plots of 314 m2 were established along a transect lines. Soil seed bank analysis was done from soil samples collected in each of the plots (225 samples). Different diversity index and ANOVA was used in SPSS software for analysis. The result showed that a total of 51 woody plant species was recorded in adjacent natural forest (41), managed C. lusitanica (27), not managed C. lusitanica (9), managed E. globules (22) and not managed E. globules (13) species. Regeneration of seedlings were 3538, 5567, 707, 1462 and 2524 mean stems ha-1 for natural forest, managed C. lusitanica, not managed C. lusitanica, managed E. globules and not managed E. globules respectively. Unmanaged C. lusitanica plantations had significantly lower densities of mature tree stems ha-1 as compared to managed C. lusitanica, managed E. globules and adjacent natural forest (F=14.03, p<0.05). Similarly in terms of sapling density ha-1 unmanaged C. lusitanica was significantly lower from other forest types (F=7.37, p <0.05). However managed C. lusitanica had significantly higher seedling regeneration (stem density ha-1) than other plantation and adjacent natural forests (F = 16.11, p < 0.05). Generally mean stem densities including tree, sapling and seedling of woody species among different forest types managed C. lusitanica was significantly higher among different forest types (F= 13.01, p<0.05). From the soil seed bank a total of 22 plant species (20 native and 2 exotic) species were recovered. In different forest types the number of species recorded was in adjacent natural forest (19), managed C. lusitanica (11), unmanaged C. lusitanica (4), managed E. globules (7) and unmanaged E. globules (5). Generally, with appropriate management intervention, undergrowth vegetation and soil seed bank status in plantation forest had good species composition and diversity.

Effect of Forest Cover on Raptor Abundance in Exotic Forest Plantations in Chile

Habitat specialists, such as forest raptors, are generally more likely to suffer from the impacts of large-scale forestry. One of the most characteristic and controversial aspects of many industrial plantation systems is the use of clearcutting as a harvesting method, which generates a mosaic of highly contrasting land cover types, such as wooded areas adjacent to zones practically devoid of vegetation. We explored the effect of forest cover on the abundance of habitat-generalist and forest-specialist raptors in South-central Chile. During the 2016 to 2018 breeding seasons, we conducted 584 playback surveys at 149 sampling points centred on 3×3km plots within 9×9km squares. The Rufous-legged Owl Strix rufipes, a forest specialist, showed a positive relationship with forest cover at the local scale. However, we found no significant relationships for other forest specialists in this study. Most habitat-generalist species showed a negative or non-linear relationship with forest cover, with greater species abundances observed in landscapes with intermediate levels of forest and open areas. Interestingly, the models with the highest statistical support included total forest cover (native forest + plantations) as a predictor, suggesting that the habitat-generalist species did not significantly discriminate between natural and artificial forests. Our results show that both generalist and forest-specialist raptors can use landscapes dominated by exotic plantations in South-central Chile.—Santander, F., Alvarado O., S. & Estades, C.F. (2021). Effect of forest cover on raptor abundance in exotic forest plantations in Chile. Ardeola, 68: 391-408.

Activity and habitat use by understory birds in a native Andean forest and a eucalypt plantation

Eucalypt plantations alter the physical and chemical conditions of the environment, and the value of such plantations for biodiversity conservation is controversial. Research on their potential effects on native Neotropical bird communities has focused on taxonomic diversity, while its impacts on other ecological aspects remain only partially explored. We used camera traps to compare habitat use and activity patterns of an understory bird assemblage between a native forest and an adjacent eucalypt plantation in the Colombian Andes. Six and seven understory bird species comprised the eucalypt plantation and the native forest assemblages, respectively. Habitat use of the White-throated Quail-Dove (Zentrigon frenata), Sickle-winged Guan (Chamaepetes goudotii), and antpittas was significantly lower in the plantation, whereas brushfinches used both forest types equally. Each species showed coefficients of activity that overlapped above 59%, suggesting the overall activity patterns of the understory birds were similar in both forest types. However, activity peaks of most species were slightly different between the 2 forests. Despite the fact that these areas are adjacent to one another, and that this eucalypt plantation has undergone 50 years of understory growth, our results indicate that this exotic plantation does not constitute a suitable habitat for most Andean understory birds. We found that eucalypt plantation effects on bird assemblages go beyond their taxonomic diversity and affect other ecological aspects such as their patterns of activity. Our study provides new insights on activity patterns of Andean birds and highlights the need for assessing the value of exotic plantations as a surrogate habitat for understory bird conservation.

Exotic tree plantations as alternative breeding habitat for an endemic avian predator

Forest‐dwelling raptors living on islands are more vulnerable than continental relatives due to their particular life history traits and habitat degradation. The Canary Islands' forests have suffered severe transformations because of intense human exploitation since its colonization by the Europeans. In recent decades, forest managers have initiated actions to restore the original ecosystems. Consequently, gathering knowledge on the relationships between habitat and reproduction output of forest species is essential to develop long‐term conservation actions. Here, we explore the suitability of exotic tree plantations as breeding habitat for an island endemic raptor, the Macaronesian sparrowhawkAccipiter nisus granti. We monitored territories distributed in three main forest types, two native (laurel forest and Canarian pinewood) and one composed of exotic trees. We assessed breeding density, characterized nesting habitat at macro‐, micro‐habitat and nest tree levels, and estimated breeding parameters in the three forests. We evaluated habitat selection and its potential relationship with breeding parameters, as well as nest structure survival in native versus exotic tree species. Density was higher in exotic forests and habitat features differed among forests at three spatial scales. Sparrowhawks used areas with high cover of exotic trees, with high trees, far away from human settlements and at low altitudes. All models testing for differences in breeding success and productivity among the forest types were not significant, but the percentage of successful pairs was slightly higher in exotic tree plantations than in native forests. Nest structures located in exotic trees showed a higher annual survival than those placed in native trees. Our results indicate that exotic plantations are a secure nesting habitat and therefore forestry practices, including those aiming to eradicate exotic trees, must be carefully planned to avoid nest destruction or disturbance in occupied forest patches.

Changed avian assemblage of Savitribai Phule Pune University campus in last four decades

Savitribai Phule Pune University is known for its biodiversity in Pune. In the present study, we have analyzed changes which have occurred on the campus and surrounding area over the last 40 years. Of the 90 bird species reported in the campus and Khadki pond in 1976, we failed to notice 34 species in 2018. A major reason for the decline in bird diversity could be changes in the campus habitat from low scrub jungle, fallow lands and grassland to buildings, roads, and exotic plantations. Increase in human settlement surrounding the campus may also be a contributing factor. Replacing exotic plants by indigenous plant species and control of land use can prevent further loss of biodiversity.

Persistence of the Swiss Needle Cast Outbreak in Oregon Coastal Douglas-Fir and New Insights from Research and Monitoring.

Swiss needle cast (SNC), caused by Nothophaeocryptopus gaeumannii, is a foliage disease of Douglas-fir (Pseudotsuga menziesii), that reduces growth in native stands and exotic plantations worldwide. An outbreak of SNC began in coastal Oregon in the mid-1990s and has persisted since that time. Here we review the current state of knowledge after 24 years of research and monitoring, with a focus on Oregon, although the disease is significant in coastal Washington and has recently emerged in southwestern British Columbia. We present new insights into SNC distribution, landscape patterns, disease epidemiology and ecology, host-pathogen interactions, trophic and hydrologic influences, and the challenges of Douglas-fir plantation management in the presence of the disease. In Oregon, the SNC outbreak has remained geographically contained but has intensified. Finally, we consider the implications of climate change and other recently emerged foliage diseases on the future of Douglas-fir plantation management.

The impact of forest science in Chile: history, contribution, and challenges

In this article we describe Chile’s transition from an agriculture productive model that originated in the 19th century into a more complex economic model that incorporates forest production, explaining the role of forest sciences in this process. Forest science has made great contributions to the country, especially in terms of improving forestation and forest management techniques that have allowed the rapid expansion of the forestry industry and prevented soil erosion on degraded lands. However, native forests have been neglected and vast areas of forest have been replaced with exotic plantations. This process has highlighted the imperative need for developing a new productive model to ensure not only a fair distribution of wealth but also the use of science-based sustainable forest management practices to protect native forest ecosystems nationwide. A national strategic plan for managing, conserving, and restoring native forests is needed not only to align the forest industry with sustainable development but also to develop sound climate change strategies to achieve the country’s goal of becoming carbon neutral by 2050. Under this scenario forest science can play an important role by producing much needed evidence-based knowledge.

True bugs (Hemiptera: Heteroptera) associated with dead wood in exotic Pinus radiata plantations in New Zealand

ABSTRACT This paper reports the true bugs (Heteroptera) collected during a large-scale study of saproxylic insects in exotic pine plantations in New Zealand, reared from Pinus radiata dead wood in the central North Island in 2009–2010. Although only seven species were collected in total, the observations of two flightless flat bug (Aradidae) species indicate that exotic pine forests may provide alternative habitat for dispersal-limited endemic forest invertebrates. An important finding is the first New Zealand record of the Australian aradid Glochocoris monteithi. Assuming this find represents the existence of an established local population, this would be only the third documented case of a flat bug successfully establishing in another major zoological realm.

Effects of Exotic Plantation and Management Intervention on Woody Plant Species Diversity, Regeneration and Soil Seed Bank in Tarmaber District, Ethiopia

Plantations have many economic and environmental benefits, but exotic plantations are widely viewed negatively mainly in relation to biological diversity conservation, and regenerations to prove this dilemma this study is necessary. This study was carried out in Tarmaber district north shewa zone Ethiopia to determine the effect of plantation forest with management intervention on woody plant species diversity, regeneration and soil seed bank species composition in five different forest types. A total of 75 circular sample plots of 314 m² were established along a transect lines. Soil seed bank analysis was done from soil samples collected in each of the plots (225 samples) to examine the similarity between the soil seed bank and aboveground flora. Different diversity index and ANOVA was used in SPSS software for analysis. The result showed that a total of 51 woody plant species was recorded in adjacent natural forest (41), managed <i>C. lusitanica</i> (27), not managed <i>C. lusitanica</i> (9), managed <i>E. globules</i> (22) and not managed <i>E. globules</i> (13) species. Regeneration of seedlings were 3538, 5567, 707, 1462 and 2524 mean stems ha^-1 for natural forest, managed <i>C. lusitanica</i>, not managed <i>C. lusitanica</i>, managed <i>E. globules</i>and not managed <i>E. globules</i>respectively. Unmanaged <i>C. lusitanica</i>plantations had significantly lower densities of mature tree stems ha^-1 as compared to managed <i>C. lusitanica</i>, managed <i>E. globules</i>and adjacent natural forest (F=14.03, p<0.05). Similarly in terms of sapling density ha^-1 unmanaged <i>C. lusitanica</i> was significantly lower from other forest types (F=7.37, p <0.05). However managed <i>C. lusitanica</i>had significantly higher seedling regeneration (stem density ha^-1) than other plantation and adjacent natural forests (F = 16.11, p < 0.05). Generally meanstem densities including tree, sapling and seedling of woody species among different forest types managed <i>C. lusitanica</i> was significantly higher among different forest types (F= 13.01, p<0.05). From the soil seed bank a total of 22 plant species (20 native and 2 exotic) species were recovered. In different forest types the number of species recorded was in adjacent natural forest (19), managed <i>C. lusitanica</i> (11), unmanaged <i>C. lusitanica</i> (4), managed E. globules (7) and unmanaged <i>E. globules</i> (5). The similarity of the soil seed bank was more or less similar to the above ground flora with maximum Sorenson’s similarity values of 0.633. Generally with appropriate management intervention undergrowth vegetation and soil seed bank status in plantation forest had good species composition and diversity.

An alternative broad vegetation hierarchy for eastern New South Wales, with application for environmental planning and management

Many previous vegetation description and mapping programs have highlighted the need for a hierarchical classification that easily translates from regional through to international scales. Often programs have not selected appropriate levels of vegetation classification and mapping for management purposes. Here, we provide an alternative broad vegetation classification at the macrogroup level in the international vegetation classification for eastern New South Wales (NSW) that could be applied in regional and local environmental planning and management. Existing aerial photographic interpretation (API) floristic and canopy maps available for eastern NSW were collated and reclassified and incorporated into a unifying dataset of macrogroups, which also included types dominated by exotic vegetation such as exotic plantations. There we identified, in total, 71 macrogroups across eastern New South Wales (NSW) of a total of 85 identified for NSW mapped at 1:25 000 scale, or finer, in the following three sections: north-east, Sydney basin and central west, and southern coast and Snowy Mountains. These were then amalgamated into a single remnant vegetation map covering 23 525 280 ha. This alternative broad vegetation hierarchy provides a reliable and overt vegetation classification and mapping dataset that can easily incorporate future revisions as new mapping data become available.

Influence of native and exotic tree plantations on biophysical indicators in the Brazilian Savanna

ABSTRACT The monitoring of biophysical indicators can show the conservation or recovery status of a landscape. This study aimed to analyze the influence of tree plantations on the dynamics of biophysical indicators (albedo, NDVI, surface temperature and evapotranspiration), in an experimental area of the Cerrado biome (Brazilian Savanna), by applying remote sensing techniques and the SEBAL algorithm. The indicators dynamics were given as a function of changes in the land use, while assessing the response of the environment to the planting of tree species. SEBAL data on areas that underwent changes in land use and cover during this period were analyzed. In the surroundings of the experimental area, albedo and surface temperature decreased in agricultural and exposed soil areas converted to tree plantations, while the NDVI and evapotranspiration increased. The opposite happened in the conversion of native areas destined to agriculture and livestock. In the experimental area, it was confirmed that the plantations contributed not only to the decrease in the surface and albedo temperature, but also to the increase in the NDVI and evapotranspiration. This confirms the positive influence of tree planting in rural properties of the Cerrado as a support to environmental regularization and more sustainable agricultural systems. Moreover, it highlights the potential of the technique applied to assist in monitoring Cerrado ecosystems in areas larger than those commonly monitored in the field.

Monitoreo de la sucesión de especies vegetales leñosas bajo una plantación de Pinus radiata D. Don, en el parque universitario “Francisco Vivar Castro”, provincia de Loja, Ecuador

En los andes del Ecuador existen plantaciones de Pinus radiata y Pinus patula, sembradas entre matorrales, páramos y áreas abiertas; y, se desconoce la sucesión vegetal, sus cambios y desarrollo. Se investigó una plantación de Pinus radiata en la hoya de Loja con el objetivo de caracterizar la composición florística y monitorear la regeneración natural considerando categorías de regeneración: plántulas, brinzales y latizales. Se establecieron 5 parcelas de 20 m x 20 m, se anidaron 5 subparcelas de 5 m x 5 m y 5 subparcelas de 1 m x 1 m. Se midió altura y diámetro basal. Se determinó la sobrevivencia y crecimiento en un periodo de 12 meses; se analizó la influencia de variables ambientales: luminosidad, pendiente, profundidad del suelo horizonte O, sobre la diversidad y abundancia de la regeneración natural. Se identificaron 24 especies, 21 géneros y 22 familias. La mayor diversidad presentan los latizales; las especies con mayor IVI en las tres categorías son: Piper barbatum, Viburnum triphyllum y Frangula granulosa. Los latizales presentan mayor sobrevivencia (99,37 %), seguida por brinzales (87,59 %) y plántulas (82,76 %). El incremento en altura y diámetro es mayor en Frangula granulosa, Clusia latipes, Critoniopsis pycnantha y Alnus acuminata. No existe influencia significativa de los factores ambientales sobre la diversidad y abundancia de la regeneración natural. La regeneración natural encontrada en las condiciones de hábitat de la plantación; demuestra que es factible la recuperación de la vegetación natural y la presencia de un bosque natural cuando desaparezca la plantación forestal.

Seed bank responses after clearcutting Pinus patula plantations in Andean high montane areas

Clear cutting exotic plantations favours natural regeneration processes in which seed banks may play an important role. In Andean high montane areas, after Pinus patula clear cutting, changes in soil pH and litter lead to increased fauna and flora biodiversity. However, the impactof these changes on seed banks remains unknown. The aims of the present study were to understand how seed bank richness, abundance, and composition changes after p. patula clear cutting, and to identify the role of above ground cover, pH and litter cover on these seed bank variations. The study was conducted in three areas with different post-clear cutting ages (0,2.5,4.5 years), a p. patula plantation and in a high Andean forest patch. All these sites were located between 3033 and 3100 m.a.s.l. Seed bank abundance, richness and the number of seeds of the ten most abundant species increased in areas with 2.5 and 4.5 years after clear cutting. Moreover, seed bank composition was different among study areas. These changes were related to increasing above ground vegetation cover and soil pH, and to decreasing litter cover. Seed banks contributed almost exclusively to the recovery of some herbaceous species; were corded only one tree species recruit from the seed banks (Baccharislatifolia) in the forest soils; therefore, the natural regeneration processes may be constrained. Our results high light the need to implement active restoration to accelerate high montane forest recovery in areas previously covered with pine tree plantations.

Quantitative Genetic Variation in Bark Stripping of Pinus radiata

Bark stripping by mammals is a major problem for conifer forestry worldwide. In Australia, bark stripping in the exotic plantations of Pinus radiata is mainly caused by native marsupials. As a sustainable management option, we explored the extent to which natural variation in the susceptibility of P. radiata is under genetic control and is thus amenable to genetic improvement. Bark stripping was assessed at ages four and five years in two sister trials comprising 101 and 138 open-pollinated half-sib families. A third younger trial comprising 74 full-sib control-pollinated families was assessed at two and three years after planting. Significant additive genetic variation in bark stripping was demonstrated in all trials, with narrow-sense heritability estimates between 0.06 and 0.14. Within sites, the amount of additive genetic variation detected increased with the level of bark stripping. When strongly expressed across the two sister trials, the genetic signal was stable (i.e., there was little genotype × environment interaction). No significant non-additive effect (specific combining ability effect) on bark stripping was detected in the full-sib family trial, where it was estimated that up to 22.1% reduction in bark stripping might be achieved by selecting 20% of the less susceptible families. Physical traits that were genetically correlated, and likely influenced the amount of bark removed from the trees by the marsupials, appeared to depend upon tree age. In the older trials, these traits included bark features (presence of rough bark, rough bark height, and bark thickness), whereas in the younger trial where rough bark was not developed, it was the presence of obstructive branches or needles on the stem. In the younger trial, a positive genetic correlation between prior height and bark stripping was detected, suggesting that initially faster growing trees exhibit more bark stripping than slower growing trees but later develop rough bark faster and became less susceptible. While the presence of unexplained genetic variation after accounting for these physical factors suggests that other explanatory plant traits may be involved, such as chemical traits, overall the results indicate that selection for reduced susceptibility is possible, with potential genetic gains for deployment and breeding.

Impact of pine plantation establishment on soil properties and fungal communities of natural forests in Zimbabwe

Globally, large expanses of land were cleared for the establishment of exotic pine and eucalypt tree plantations for commercial purposes. In Zimbabwe, these plantations resulted in the clearance of over 120 000 ha of native vegetation, especially miombo woodlands that are dominant in wetter regions of the country, to which these exotic species are mostly suited. To evaluate the effect of exotic pine plantations on soil physicochemical properties and fungal communities, we studied a second rotation pine plantation and adjacent miombo woodland. Soil nutrient concentration and pH were consistently higher (p < 0.05) in the miombo woodland compared to pine plantation soils. Although both land uses were dominated by fungi belonging to Dikarya, pine plantation soil was dominated by Basidiomycota (69.1%) while miombo woodland soil was dominated by Ascomycota (66.1%). Basidiomycota in pine plantation soil was dominated by ectomycorrhizal associates of pine while Ascomycota in miombo woodland soil was dominated by saprophytic fungi.

Soil type modulates the response of C, N, P stocks and stoichiometry after native forest substitution by exotic plantations

Natural forests conversion to intensively managed forest plantation is an expanding land-use change that could profoundly impact C and nutrient terrestrial cycles. Here we assessed how different soil types respond to changes in the C, N, and P major biogeochemical pools by comparing paired natural broadleaf deciduous forest and pine plantation across five different soils with contrasting mineralogy. We quantified major biogeochemical stocks in all soil compartments to a depth up to 240 cm, including the forest floor. Our result showed that soils' C, N, and P stocks and stoichiometry do not respond equally to this land-use change. Deep soil biogeochemical pools (120–240 cm) contributed substantially to the total soil stock in most sites (up to 40% for C, 47% for P, and 52% for P). Elemental depth distribution was significantly modified because of forest substitution, and some sites displayed a significant stock reduction in deep soil compartments (>120 cm). Whole mineral soil C and N stocks were generally lower in the planted forest, while these stocks in litter layers were significantly different between soil and forest types (p < 0.001). C and N stocks in soils with low clay content or low activity clays were more significantly affected by forest substitution. On the other hand, soils with moderate to high clay content and dominant high activity clay were only mildly affected by this change. Phosphate and ammonium available pools were more affected in low activity and low clay content soil. P pools, and consequently C:P and N:P ratios in mineral soils, vary significantly between soil types. Our results corroborate that soils with contrasting properties respond differently to native forest substitution to intensively managed plantations and that the magnitude of this response seems to be controlled mostly by clay mineralogy.