Productivity of conifer forests and especially natural forest regeneration on the felling with regard to forest soil fertility

Цель исследования – выявить влияние эффективного плодородия лесных почв на продуктивность чистых по составу ельников и сосняков, а также на ус- пешность последующего естественного лесовозобновления на вырубках. Эффективное плодородие лесных почв по О.Г. Чертову – это отношение мощности гу- мусового горизонта к мощности лесной подстилки (гумусо-подстилочный коэффициент, ГПК). Продуктивность взрослых ельников Ленинградской области имеет высокую прямую корреляционную связь с ГПК (R2 = 0,884). Наивысшая продуктивность ели (бонитеты Iа и Iа,5) характеризуется коэффициентами плодо- родия, равными соответственно 2 и 2,3. Зависимость продуктивности сосняков от ГПК оказалась значительно менее тесной, чем ельников (R2 = 0,464). В сосняках с наивысшей продуктивностью (бонитеты Iа,5-Iб,5) ГПК составляет 1,7–3,5. На вы- рубках давностью 5–15 лет величина ГПК закономерно возрастает по исходным типам леса от бедных к сравнительно богатым местообитаниям. При этом изме- няются густота и состав подроста, как общего, так и подроста хвойных пород. Наибольшая общая густота подроста (20–22 тыс. экз./га), с достаточно большой долей хвойного подроста – 5–6 тыс. экз./га – характерна для почв среднего плодо- родия (ГПК = 1,2), но с некоторым переувлажнением – в типах леса черничники влажные и долгомошники. Наибольшее количество подроста хвойных пород (с преобладанием сосны в составе) – 8–13 тыс. экз./га – присуще бедным и сухим местообитаниям (вересковый и брусничный типы леса). С увеличением эффек- тивного плодородия почв происходит смена подроста сосны на подрост ели, при- чем густота подроста хвойных в целом снижается. Эта густота имеет нелинейную тесную отрицательную связь с ГПК (R2 = 0,916). Густота подроста березы от пло- дородия почвы не зависит (R2 = 0,025), тогда как густота подроста осины имеет с ним высокую положительную связь (R2 = 0,706). Разрастание подлеска с ГПК слабо связано, но в большинстве случаев подлесок снижает густоту подроста хвойных пород и, в частности, подроста сосны. Разрастание трав, особенно зла- ков, характерно для богатых почв, и также оказывает существенное отрицатель- ное влияние на густоту хвойного подроста. Таким образом, почвы, обладающие наибольшим эффективным плодородием, после вырубки материнского древостоя быстро заселяются конкурентами сосны и ели: травами, подлеском и лиственны- ми породами, прежде всего осиной. Следовательно, по исходному типу леса и со- ставу древостоя, определяющим эффективное плодородие почв, при отсутствии хозяйственных мер по содействию естественному возобновлению хвойных пород, можно уверенно прогнозировать успешность естественного последующего лесовосстановления всех лесообразующих пород на вырубках. The purpose of the study is to determine the impact of effective forest soil fertility on productivity of spruce and pine stands of pure the composition, as well as the success of the subsequent natural forest regeneration on the felling. Effective forest soil fertility by O.Chertov is the ratio of thickness the humus horizon and forest litter (humus-litter coefficient, HLC). Spruce productivity Leningrad region has high direct cor- relation with HLC (R2 = 0.884). The highest productivity trees (quality class IA and Ia, 5) is characterized by fertility coefficients, equal respectively 2.3 and 2. Dependence of productivity pine stands from HLC was significantly less close than spruce stands (R2 = 0.464). In stands with the highest productivity (quality class Ia, 5-Ib, 5) HLC is 1.7–3.5. On the felling where prescription 5–15 years the amount of HLC naturally in- creases the original forest types from the poor to the relatively rich habitats. This change the density and composition of forest regeneration, both general and regenera- tion of conifers. The highest overall density of forest regeneration (20–22 thousand copies./ha), with a fairly large portion of pine regeneration is 5–6 thousand copies./ha characteristic soil medium fertility (HLC = 1.2), but with some excessive moisture – polytrichosum and nass myrtillosum. The largest number of young conifers (pine- dominated composition) – 8–13 thousand copies./ha is inherent in the poor and arid habitats (vacciniosum and сladinosum forest types). With the increase of effective soil fertility changes of young pines on young spruce, with undergrowth density conifers declines in general. This density has a close relationship with negative nonlinear HLC (R2 = 0.916). Density undergrowth of birch from the soil fertility is not affected (R2 = 0.025), whereas the density of aspen regrowth has with him a high positive rela- tionship (R2 = 0.706). Growth of underbrush with HLC loosely connected, but in most cases the underbrush reduces density undergrowth of coniferous species and, in partic- ular, young pine. Growth of grasses, especially cereals, characteristically for the rich soil, and also has a significant negative effect on density pine regrowth. Thus, soil, possessing the highest effective fertility, after cutting down maternal stand soon devel- oped by competitors of pine and spruce: herbs, underbrush and deciduous breeds, pri- marily aspen. Consequently, the original forest stand composition and type, determin- ing effective soil fertility, in the absence of management measures on assistance to natural regeneration of coniferous breeds, we can confidently predict the success of a natural follow-up reforestation of all felling.

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Evaluating Plantation Forest vs. Natural Forest Regeneration for Biodiversity Enhancement in Hong Kong

Forests ◽

10.3390/f12050593 ◽

2021 ◽

Vol 12 (5) ◽

pp. 593

Author(s):

Janet E. Nichol ◽

Sawaid Abbas

Keyword(s):

Hong Kong ◽

Species Richness ◽

Forest Regeneration ◽

Forest Succession ◽

Natural Forest ◽

Plantation Forestry ◽

Aerial Photographs ◽

Continuous Increase ◽

Natural Forest Regeneration ◽

Spatio Temporal

Global trends predict a continuous increase in the proportion of forest occupied by plantations up to the end of the 21st century, while a dramatic loss of biodiversity is foreseen as a result of anthropogenic exploitation and climate change. This study compares the role and performance of plantation policies in Hong Kong, with natural regeneration of secondary forest, using detailed spatio-temporal data extracted from a previous study. The study extends over a 70-year period from 1945 to 2014 using aerial photographs and satellite images of five time periods to document spatio-temporal trends in plantation forestry and natural forest succession. Field data on species richness and woody biomass at different stages of forest succession are compared with available data from plantations in the same study area. Results indicate that plantation forests support relatively few native species in the understory, with much lower species richness than naturally regenerated forest, even after 6 to 7 decades. Time-sequential maps of habitat change show that natural forest succession from barren grassy hillsides, progressed at an annual rate of 7.8%, from only 0.2% of the landscape post WWII, to over 37% today. Plantation forestry on the other hand has been less successful, and has even acted as a barrier to natural forest regeneration, as mono-cultural plantations from the late 1960s to 1980s are still plantations today, whereas other similar areas have succeeded naturally to forest. The theory of plantations acting as a nurse crop for a woody native understory is not supported, as Pinus massoniana plantations, destroyed by two deadly nematodes during the 1970s, apparently had no woody understory, as they were seen to have reverted to grassland in 1989 and are still mainly grassland today.

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The Impact of Nickel Mining on Soil Properties and Growth of Two Fast-Growing Tropical Trees Species

International Journal of Forestry Research ◽

10.1155/2020/8837590 ◽

2020 ◽

Vol 2020 ◽

pp. 1-9

Author(s):

Ricksy Prematuri ◽

Maman Turjaman ◽

Takumi Sato ◽

Keitaro Tawaraya

Keyword(s):

Forest Soil ◽

Dry Weight ◽

Natural Forest ◽

Total Carbon ◽

Available Phosphorus ◽

Shoot Height ◽

Fast Growing ◽

Shoot Dry Weight ◽

Nickel Mining ◽

The Impact

Opencast nickel mining is common in natural forests of Indonesia. However, rehabilitation of postmining degraded land is difficult. We investigated the effect of opencast nickel mining on soil chemical properties and the growth of two fast-growing tropical tree species, Falcataria moluccana and Albizia saman. Soil was collected from post-nickel mining land and a nearby natural forest. Soil pH, available phosphorus (P) concentration, total carbon (TC) and total nitrogen (TN) concentration, C/N ratio, cation exchange capacity (CEC), and exchangeable K, Na, Mg, Ca, Fe, and Ni concentrations were determined. Falcataria moluccana and A. saman were then grown in the collected soils for 15 weeks in a greenhouse. Shoot height and shoot and root dry weights of the seedlings were measured. The post--nickel mining soils TN, TC, available P, CEC, and exchangeable Ca and Na concentrations decreased by 98%, 93%, 11%, 62%, 85%, and 74%, respectively, in comparison with the natural forest soils. The pH of postmining soil was higher than natural forest soil. Shoot dry weight of F. moluccana seedlings grown in postmining soil was significantly ( P < 0.05 ) lower than that of seedlings grown in natural forest soil. However, there was no difference in shoot dry weight between A. saman seedlings grown in natural forest soil and postmining soil, as well as root dry weights of both species. The results indicate that opencast nickel mining decreased soil fertility, which subsequently inhibited the growth of F. moluccana and A. saman seedlings.

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Optimum Design of Laterally Supported Castellated Beams Using Natural Forest Regeneration Algorithm

Iranian Journal of Science and Technology Transactions of Civil Engineering ◽

10.1007/s40996-016-0024-1 ◽

2016 ◽

Vol 40 (3) ◽

pp. 195-207 ◽

Cited By ~ 1

Author(s):

A. Kaveh ◽

F. Shokohi

Keyword(s):

Optimum Design ◽

Forest Regeneration ◽

Natural Forest ◽

Natural Forest Regeneration

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Assessment of the impact of the urbanized territory of Yekaterinburg city on the formation of undergrowth in the forest park zone

BIO Web of Conferences ◽

10.1051/bioconf/20213800130 ◽

2021 ◽

Vol 38 ◽

pp. 00130

Author(s):

Olga Tolkach ◽

Olga Dobrotvorskaya

Keyword(s):

Natural Forest ◽

Forest Types ◽

Floristic Similarity ◽

Adventive Species ◽

Forest Park ◽

Urbanized Territory ◽

Growing Conditions ◽

Forest Parks ◽

A Site ◽

The Impact

The parameters of the undergrowth in the forbs and berry groups of pine forest types in 9 parks in Yekaterinburg and areas of natural forest have been investigated. Data on the species composition, density, and distribution by groups of heights of plants that make up the undergrowth collected. It has been established that the transformation of the undergrowth by an urbanized environment neutralizes the influence of the growing conditions of the considered forest types on it. In the forest-park zone, an increase in the density of the undergrowth is observed in comparison with the natural forest. The specificity of the forest park undergrowth is the floristic contamination with adventive species, the number of which is close to 50% of the total number of undergrowth species. The coefficient of floristic similarity of the undergrowth, according to the Sorensen coefficient between forest parks and a site of natural forest, was 0.26-0.46. In quantitative terms, the self-seeding of adventive species in the undergrowth is less than that of native plants. The invasive activity of ash-leaved maple in city parks and its dynamics over a 10-year period are considered, using the example of one of the parks.

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Structural changes to forests during regeneration affect water flux partitioning, water ages and hydrological connectivity: Insights from tracer-aided ecohydrological modelling

Hydrology and Earth System Sciences ◽

10.5194/hess-25-4861-2021 ◽

2021 ◽

Vol 25 (9) ◽

pp. 4861-4886

Author(s):

Aaron J. Neill ◽

Christian Birkel ◽

Marco P. Maneta ◽

Doerthe Tetzlaff ◽

Chris Soulsby

Keyword(s):

Land Cover ◽

Land Cover Change ◽

Forest Regeneration ◽

Structural Changes ◽

Water Flux ◽

Natural Forest ◽

Hydrological Connectivity ◽

Area Index ◽

Flux Partitioning ◽

Natural Forest Regeneration

Abstract. Increasing rates of biodiversity loss are adding momentum to efforts seeking to restore or rewild degraded landscapes. Here, we investigated the effects of natural forest regeneration on water flux partitioning, water ages and hydrological connectivity, using the tracer-aided ecohydrological model EcH2O-iso. The model was calibrated using ∼ 3.5 years of diverse ecohydrological and isotope data available for a catchment in the Scottish Highlands, an area where impetus for native pinewood regeneration is growing. We then simulated two land cover change scenarios that incorporated forests at early (dense thicket) and late (old open forest) stages of regeneration, respectively. Changes to forest structure (proportional vegetation cover, vegetation heights and leaf area index of pine trees) were modelled for each stage. The scenarios were then compared to a present-day baseline simulation. Establishment of thicket forest had substantial ecohydrological consequences for the catchment. Specifically, increased losses to transpiration and, in particular, interception evaporation drove reductions in below-canopy fluxes (soil evaporation, groundwater (GW) recharge and streamflow) and generally slower rates of water turnover. The greatest reductions in streamflow and connectivity were simulated for summer baseflows and small to moderate events during summer and the autumn/winter rewetting period. This resulted from the effect of local changes to flux partitioning in regenerating areas on the hillslopes extending to the wider catchment by reducing downslope GW subsidies that help sustain summer baseflows and saturation in the valley bottom. Meanwhile, higher flows were relatively less affected, especially in winter. Despite the generally drier state of the catchment, simulated water ages suggested that the increased transpiration demands of the thicket forest could be satisfied by moisture carried over from previous seasons. The more open nature of the old forest generally resulted in water fluxes, water ages and connectivity returning towards baseline conditions. Our work implies that the ecohydrological consequences of natural forest regeneration depend on the structural characteristics of the forest at different stages of development. Consequently, future land cover change investigations need to move beyond consideration of simple forest vs. non-forest scenarios to inform sustainable landscape restoration efforts.

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