Assessment of the Impact of Forest Reclamation Measures for the Adaptation of Agriculture to Climate Change in the South of the Russian Plain

Abstract

The aim of this study was to study the effectiveness and economic efficiency of the impact of agroforestry complexes on the adaptation of agriculture to climate change in the south of the Russian Plain. It has been established that this manifests quantitatively in a significant decrease (by almost a third) in the area of wind-destroyed lands and drought-dead crops in farms protected by forest strips compared with open agricultural territories. The calculation of direct damage prevented by protective forest plantations from degradation and loss of soil fertility as a result of dust storms and indirect damage prevented by protective forest plantations from crop loss as a result of extreme droughts shows that the total amount of remuneration received by farmers from agroforestry in connection with the placement of a forest-forming element in their fields is EUR 317–1239 ha⁻¹ year⁻¹. This value is the contribution of agroforestry to adaptation to climate change and is subject to zonal dynamics—it depends on natural and climatic conditions. The application developed as part of this research has value for decision makers, since it allows for preliminary assessment of the effectiveness and efficiency of agroforestry for various areas of farms and various natural zones.

1. Introduction

Climate change is a global problem and affects all countries of the world. Recurrent abnormal droughts, dust storms, desertification, changing precipitation patterns, floods, and sea level rise are some of the effects of climate change that currently affect people and nature and will continue to do so in the future [1].

One of the negative consequences of climate change is global warming. It increases the frequency and intensity of extreme weather events, contributes to desertification and land degradation, and negatively affects food security and terrestrial ecosystems in many regions of the world. Global warming is a subset of climate change [2]. Human impact on the environment, along with an increase in the intensity and duration of extreme heat waves, has significantly increased global warming in recent years [3].

Modern agriculture contributes to climate change by causing it and also undermines the foundations of its own existence and, consequently, suffers from it. Thus, it not only contributes to climate change, but is also affected by it. Modern agriculture is simultaneously accelerating climate change and experiencing damage from climate change [4].

Climatic changes directly affect the production performance of many crops. The average yield of many of them (for example, corn, sorghum, wheat, or rice) decreases as a result of exceeding a certain maximum temperature threshold. Thus, a long-term increase in temperature will contribute to a decrease in future yields, on both irrigated and arid lands [5].

As a result of these circumstances, politicians in many countries are forced to focus on the recommendations of the sustainable development agenda (Sustainable Development Goals (SDGs)) for the period up to 2030. They recognize that adaptation to climate change is necessary for sustainable agriculture. The most appropriate way of doing this is to introduce methods into the agricultural sector that mitigate the effects of climate change [6].

There is an unquestioned scientific consensus in the world that the combination of forestry with agricultural crops is effective, and agroforestry systems can provide additional ecosystem services compared to monoculture systems. It is recognized that agroforestry has great potential as a solution for adaptation to climate change, which is to help farmers and landowners prepare for the effects of climate change. Agroforestry systems promote soil health and increase biological diversity. These benefits increase farmers’ resilience and their ability to cope with extreme weather events such as heavy rainfall or severe drought [7,8,9,10,11,12,13].

Agroforestry also provides a unique opportunity to combine the goals of increasing productivity and improving soil condition due to the anti-erosion functions of trees [14]. It has the potential to eliminate land degradation. Moreover, agroforestry systems can provide higher savings compared to individual agricultural or forestry systems while improving the ecology and climatic conditions of the present and future [15].

In order to understand the importance of agroforestry for achieving sustainable development goals in terms of mitigation and adaptation to climate change, as well as increase the sustainability of agriculture in arid regions, we assumed that if arable land is developed for crop rotation without first creating a system of forest strips, then after a certain time the state of the soil cover and crops degrades to the limits known to science [16,17]. These limits (parameters of soil and crop losses), in our opinion, determine the importance of agroforestry in the adaptation of the agricultural sphere to climate change. Therefore, we studied different groups of farms with and without different protective forest cover in order to identify the real effectiveness of agroforestry—to establish the main qualitative and quantitative patterns of spatial dynamics of the effectiveness of forest plantations in preventing soil deflation and crop death.

However, climate change affects different regions in different ways. The adaptation of a suitable agroforestry system varies depending on regional climatic conditions, for which the development of a suitable model is very important. Due to the further progressive deterioration of the soil and the environment in these regions, it is also important to know the impact of trees on a zonal basis in order to develop an economically sound plan for the early development of agroforestry.

Thus, the aim of this study was to analyze the effectiveness and quantify the effectiveness of agroforestry in the context of its impact on the adaptation of agriculture to climate change, as well as to determine the zonal patterns of the dynamics of these indicators.

2. Materials and Methods

2.1. Case Study Sites

The research was carried out in relation to the arid conditions of the south of the Russian Plain—in the steppe, dry steppe, and semi-desert zones located within the Volgograd Region, Russia (Figure 1) [18].

The key research area in the steppe zone was the Novonikolaevsky District. The surface is an elevated plain with heights of 200–300 m, in places strongly bisected by a valley–beam network. The climate is moderate and moderately continental (the coefficient of continentality is 165 to 190): winters are moderately mild to moderately cold (−5–12 °C) and sparsely snowy to moderately snowy (15–40 cm); summers are warm (+20–22.2 °C). The type of moisture dynamics is as follows: spring and summer are arid and semi-arid, autumn is slightly arid.

The key research area in the dry steppe was the Kletsky District. The geographical location of the area determines its high continentality of the climate and its aridity. The climate is medium and very continental (coefficient of continentality 200–220): its winter is moderately cold (−10–15 °C) and snow-free (15–25 cm), while its summer is warm (+21.6–22.5 °C). The type of moisture dynamics is as follows: dry and semi-dry summers; spring and autumn with slightly increased moisture.

The key research area in the semi-desert zone was the Pallasovsky District. The surface is a lowland characterized by an alternation of sandy massifs and flat clay plains with small depressions occupied by salty and brackish lakes and salt marshes. The climate of the zone is medium and very continental (continentality coefficient 240–250): winters are moderately mild and moderately cold (−5–15 °C) and have very little snow (10–25 cm), while summers are very warm and moderately hot (+22.5–25.8 °C). The type of moisture dynamics is as follows: all seasons are dry and semi-dry.

The main climatic parameters of the selected natural zones are presented in

Table 1. Basic climatic characteristics of natural zones of the south of the Russian Plain [19].

Natural Areas	Heat Supply		Moisture Availability		Probability of Dry and Arid Years, %
	Sum of Active Temperatures (>10 °C), °C	The Main Growing Season, Days	Precipitation, mm year−1	Hydrothermal Coefficient
Steppe zone	2719	160–180	389	0.75	0.45
Dry steppe zone	3090	160–190	350	0.55	0.53
Semi-desert zone	3200	150–175	250	0.37	0.70

.

To establish the quantitative value of the contribution of agroforestry to the adaptation of climate change in each natural zone, single-type plots of farms with different forest cover were selected (based on the ratio of the area occupied by protective forest plantations to the total area of arable land) [20]:

• The first group of farms did not have forest plantations on their lands or had only scattered, single-standing trees that did not form a complete agroforestry system and did not fully perform the functions of protecting land from negative climatic phenomena. Thus, the forest cover of the territory was ≈0.0%.
• The second group of farms had a complete system of forest plantations on their lands, fully protecting the adjacent territory from natural anomalous phenomena. The protective forest cover of this territory is optimal and amounts to 3.5%–3.8%.

Thus, groups of farms with protective forest cover of ≈0.0% and 3.8%, respectively, were studied in the steppe zone. The arable land of these farms is confined exclusively to ordinary heavy loamy and loamy chernozems. The main direction of agriculture is the cultivation of cereals and oilseeds.

In the dry steppe zone, farms with a protective forest cover of ≈0.0% and 3.5%, respectively, were studied. Chestnut soils are used in the farming of crops. The main direction of agriculture is the cultivation of grain crops.

In the semi-desert zone, farms with protective forest cover of ≈0.0% and 3.6%, respectively, were studied. The soils are light chestnut in composition with low saline content. Irrigation-free agriculture consists of the cultivation of millet and sorghum crops. Estuary irrigation is practiced.

The most active form of soil degradation within these farms is wind erosion and desertification of land.

2.2. Data Collection

Agroforestry, by mitigating the effects of climate change, helps land users to adapt to extreme and changeable weather conditions. The damage from soil degradation as a result of ultra-abnormal droughts and dust storms prevented by protective forest plantations was considered a quantitative indicator of the role of agroforestry in adaptation to climate change in regional terms.

The effectiveness of forest reclamation measures was calculated via the actual value of the percentage reduction in the area of destroyed lands and dead crops in fields with more significant forest cover, compared with low-wooded lands in identical climatic and weather conditions. These data were obtained as a result of many years of research by the Economics Department of the Federal Scientific Center of Agroecology, Complex Melioration and Protective Afforestation, Russian Academy of Sciences, Russia.

Based on biophysical data on the area of destroyed lands and dead crops in the studied natural zones, a comparative analysis of the value of degraded areas of farms of various forest cover was carried out. These data were obtained from the current reports from farms, which land users provide every year to the Agriculture Committee for the Volgograd Region [21,22].

Further, damage was assessed based on the established values of degraded lands. It included economic indicators.

The assessment of direct damage from degradation as a result of drought and dust storms was carried out according to the generally accepted compensation cost method, which is based on a replacement cost approach, where nutrient losses act as an indicator of soil fertility [23,24,25,26,27]. The research is based on quantitative biophysical data on the nutrients of zonal soils and their losses as a result of the deflation of the soil layer.

The reference humus content in zonal non-eroded soils was taken as a basis. Therefore, for ordinary chernozems, the average humus content in the steppe zone is 6.7%; in the chestnut soils of the dry steppe, 2.3%; in the light chestnut soils of the semi-desert zone, 1.7% [28,29]. Furthermore, the losses of soil organic matter were calculated based on a thorough analysis of special studies [17]. In order to arrive at a single scale of comparative assessment of the adaptation of farms to climate change (due to the lack of actual data on the degree of degradation intensity in each of them), damage was calculated based on the average degree of wind erosion of the soil layer with appropriate diagnostic signs: more than ½ of the humus-accumulative horizon is demolished and the humus content has decreased by 15%–40%. The calculations carried out in this way made it possible to “equalize” various farming systems, remove noise, and isolate and objectively assess the significance of zonal, spatial, and forest-forming factors that play a role in adaptation to climate change.

The assessment of indirect damage from degradation as a result of drought and dust storms was carried out according to a method [14,16,30] based on quantitative biophysical data on dead crops. The damage was calculated based on the cost of shortage of crop production and the cost of replanting dead crops. Calculations were performed for agricultural crops that predominate in the structure of the sown areas of the studied farms.

Compensation costs for the restoration of lost soil fertility and dead crops were obtained from prices in 2022 [31]. They were calculated based on purchase prices for the sale of fertilizers and agricultural products in rubles.

The costs of replanting dead crops were determined on the basis of a set of measures taken in the region to create and grow the main agricultural crops [32].

The obtained figures in rubles were further converted into euros at the official exchange rate set by the Central Bank of Russia, Moscow, Russia, on 1 May 2023.

2.3. Data Analyses

2.3.1. Evaluation of the Effectiveness and Efficiency of Agroforestry Measures to Adapt Agriculture to Climate Change

The effectiveness of agroforestry (EA) from the point of view of adaptation of agricultural production to climate change is determined by its ability to prevent erosion, destruction of land, and loss of crops as a result of the impact of negative natural anomalies. In other words, this is the area of agricultural forested land that remains untouched by the elements. Quantitatively, this can be traced via a comparison of two land plots—forested and open—under absolutely identical natural climatic and weather conditions at the same time:

EA = ∑∆S_i = ∑S_1i − ∑S_2i

(1)

In the formula, ∑∆S_i is the contribution of agroforestry to adaptation to climate change, ha; ∑S_1i is the area of the forested agricultural territory in the i-natural zone, where after drought and dust storms, there was no damage to farmers, destabilizing their current activities, ha; ∑S_2i is the area of open, non-forest-protected agricultural territory in the i-natural zone, where no significant damage to farmers was observed either after drought and dust storms, ha.

The relative value of the efficiency of agroforestry (EA_%, %) in the form of a percentage expression allowed us to bring to one scale, that is, to “equalize”, the sizes of different land plots of farms by area and to identify the uneven dynamics of this indicator VIA vertical (zonal) and horizontal (forest cover of agricultural land) analysis:

EA_% = (∑S_1i/∑S_1total − ∑S_2i)/∑S_2total) × 100%

(2)

In the formula, ∑S_1total and S_2total, accordingly, represent the total area of the enclosed and open area, ha.

The economic effectiveness of agroforestry in adapting to climate change is expressed through its effectiveness—direct and indirect damage prevented.

Direct anti-erosion damage (∑∆Eff_erosion, EUR ha⁻¹) is estimated from the cost of lost nutrients in the layer of degraded soil cover, equivalent to fertilizer use (C₁, tons of fertilizer ha⁻¹). Indirect macroeconomic damage (∑∆Eff_agro, EUR ha⁻¹) is estimated via the harvest of dead crops that the farmer will not receive in the future, as well as the cost of their replanting (C₂, tons of crop production ha⁻¹). In general, the effectiveness of agroforestry can be expressed in terms of additional prevented costs of farmers to shift the state of climatically altered land use to the initial level (before the “drought–dust storms” event):

$$\left\{\begin{array}{c}\sum \mathrm{f}{∆\mathrm{Eff}}_{\mathrm{erosion}}=\sum {\mathrm{S}}_{1\mathrm{i}}{\mathrm{C}}_1-\sum {\mathrm{S}}_{2\mathrm{i}}{\mathrm{C}}_1\\ \sum {∆\mathrm{Eff}}_{\mathrm{agro}}=\sum {\mathrm{S}}_{1\mathrm{i}}{\mathrm{C}}_2-\sum {\mathrm{S}}_{2\mathrm{i}}{\mathrm{C}}_2\end{array}\right.$$

(3)

The cost of compensation of soil fertility with fertilizers is obtained via the formula:

C₁ = Q₁ × Pr₁

(4)

In the formula, Q₁ is the amount of humus, subject to evaluation, tons ha⁻¹; Pr₁ is the market value of organic fertilizers, taking into account the purchase price, transportation, unloading and application to the soil, EUR.

The assessment of humus losses for each group of farms was carried out according to the formula:

$${\mathrm{Q}}_1=\frac{\mathrm{A}\times \mathrm{H}}{100\%}\times \mathrm{K}$$

(5)

In the formula, A is the weight of wind-blown zonal soil (7.5 cm layer), tons ha⁻¹; H is the amount of humus content in zonal soil, %; K is a coefficient reflecting the ratio of eroded land area to total land area of the farm.

The cost of compensation to farmers for the lost crops and the crops lost as a result of this is obtained via the formula:

C₂ = SCrop_dead × Cost + Q₂ × Pr₂

(6)

In the formula, SCrop_dead is area of dead crops, ha; Cost is the cost of measures for planting seeds in the soil and cultivating plantings, EUR; Q₂ is the gross harvest of agricultural crops, which farmers traditionally received before the “drought-dust storms” event in similar soil and climatic conditions, tons ha⁻¹; Pr₂ is the basic average market price for cereals, which is used in the regional wholesale market, EUR.

Thus, in general, the effectiveness of the contribution of agroforestry to the adaptation of agriculture to regional climate change can be expressed via the following formula:

EA = ∑∆Eff_erosion + ∑∆Eff_agro

(7)

Statistical analysis was carried out via the method of paired regression using the software program “STATISTICA 10”. The coefficient of determination of the regression model (r²) was a statistical measure in the regression model that determines the proportion of variance in the dependent variable that can be explained by the independent variable.

2.3.2. Regional Computational Mathematical Model for Assessing the Effectiveness of Agroforestry in Adaptation to Climate Change, Implementing a Diagnostic Algorithm

The computational mathematical model is presented in the form of a program for an electronic computer. A console CLI application in the C++ programming language was developed for automated calculation of the effectiveness of agroforestry. It is a high-level compiled general-purpose programming language with static typing, supporting procedural and object-oriented programming

The program implements a diagnostic algorithm for calculating direct anti-erosion and indirect agro-economic damage prevented by protective forest systems as well as their total value. The model makes it possible to evaluate the effectiveness of agroforestry for different areas of farms in all studied natural zones. Thus, the function of the computer program is based on the assessment of the value of the “agro-reclamation” adaptation of agriculture to climate change.

The regularities of the dynamics of indicators of the effectiveness and efficiency of agroforestry in adaptation to climate change were revealed using vertical analysis (zonal factor: steppe–semi-desert) and horizontal analysis (protective forest cover: ≈0%–≈100%).

3. Results

3.1. Evaluation of the Effectiveness and Efficiency of Agroforestry Measures to Adapt Agriculture to Climate Change

In the south of the Russian Plain, climatic anomalies occur every 3–6 years in the form of dust storms and droughts. The last severe drought was observed in 2022. It was accompanied by dust storms and covered most of the territory of the Volgograd Region, including the studied natural areas. The heat continued from day to day without a break. Even the night, which lengthened by 2 h 36 min over the month of August, did not bring the long-awaited coolness. The region has felt the effects of global anthropogenic warming, which has passed from the field of predictions of scientists into an objective reality. The agricultural production of the Volgograd Region turned out to be the most vulnerable to this negative phenomenon.

Despite the different level of agricultural culture in the farms of the Volgograd Region (zonal tillage technologies), the impact of meteorological factors was significant in all cases. The analysis of the average annual reporting of the studied farms (on average for 10 years) showed that climatic anomalies manifested differently in agricultural territories with different protective forest cover.

Therefore, on farms where there was no system of protective forest plantations or there were single trees, drought and wind erosion of the soil manifested very clearly. As a result of these phenomena, 40.3%–44.2% of agricultural crops were lost (

Table 2. The area of dead crops from drought and dust storms in groups of farms with different forest cover in natural zones in the south of the Russian Plain.

Natural Area/Farm Group	Protective Forest Cover of Arable Land, %	Type of Agricultural Crop	The Area of the Sown Crop, ha	Area of Dead Crops
				ha	%
Steppe zone:
Group 1 farm	≈0.0	sunflower	1407	567	40.3
Farming 2 groups	3.8	sunflower	1400	150	10.7
Dry steppe zone:
Group 1 farm	≈0.0	spring wheat	4091	1810	44.2
Farming 2 groups	3.5	spring wheat	3519	520	14.8
Semi–desert zone:
Group 1 farm	≈0.0	millet	1509	634	42.0
Farming 2 groups	3.6	millet	543	72	13.3

). On farm fields equipped with a system of protective forest plantations, the area of dead crops was 3.00–3.77 times smaller than on open land. It is noteworthy that in the semi-desert zone, the area of dead crops was about 5% smaller than in the dry steppe, despite the more arid climatic conditions. This is due to the use of partial estuary irrigation by farmers in the semi-desert zone.

It should be noted that these data obtained from farm reports indicate the overall effectiveness of agroforestry, since the degree of crop death on each farm depended on many other additional factors, including the size of the interband space, the height and design of forest stands, tillage techniques, the quality of the soil cover, etc. Nevertheless, it was possible to trace the general pattern, and in general, it can be stated that in forested fields, the death of crops was significantly less than in open areas. This indicates the contribution of agroforestry to adaptation to climate change.

Thus, the effectiveness (a kind of margin) of agroforestry measures in adapting to climate change mitigation in the steppe is 29.6%; the dry steppe, 29.4%; and the semi-desert, 28.7%, which confirms the homogeneous nature of the incoming wind and heat layer in the region under consideration (Figure 2).

Dust storms following drought cause wind erosion, causing huge damage to farmers. One of their expenses was the compensation of soil losses. It is known that the horizon A of eroded soils differs significantly in morphological structure from non-eroded soils with a lower capacity of the arable layer. On average, the removal of fine-grained soil from the topsoil during dust storms reaches a depth of 5–10 cm.

We assessed the damage to farmers from the loss of fertility of their lands as a result of the movement of soil particles across the fields. Calculations show that this damage depends on the type of zonal soil (

Table 3. Damage from the loss of nutrients of degraded soils received by farmers as a result of drought and dust storms per 1 ha of farmland when blowing the soil layer on average 7.5 cm.

Soil Type/Farm Group	Protective Forest Cover of Arable Land, %	Loss of Humus, %	Loss of Humus, tons ha−1	Fertilizer Equivalent, tons ha−1	Damage to Farmers
Steppe zone:
1 ha of eroded ordinary chernozems:	-	1.57	34.5	172.7	EUR 3074
Group 1 farm	≈0.0	-	13.9	69.6	EUR 1240
Farming 2 groups	3.8	-	3.7	18.5	EUR 329
Dry steppe zone:
1 ha of eroded chestnut soils:	-	0.84	18.5	92.4	EUR 970
Group 1 farm	≈0.0	-	8.2	40.8	EUR 429
Farming 2 groups	3.5	-	2.7	13.7	EUR 144
Semi-desert zone:
1 ha of eroded light chestnut soils:	-	0.67	14.7	73.5	EUR 772
Group 1 farm	≈0.0	-	6.2	30.9	EUR 324
Farming 2 groups	3.6	-	2.0	9.8	EUR 103

). Thus, to replenish the lost nutrients in the layer of blown soil 5–10 cm (7.5 cm on average) 1 hectare of ordinary chernozems will require 172.7 tons of organic fertilizers, particularly cattle manure. On chestnut and light chestnut soils, 1.87–2.34 times less compensation of these elements is required, which is due to their worse quality and lower initial humus content in these soils.

The regularities of the dynamics of the spatial influence of the forest-forming element on the current activities of farmers are also traced. Thus, for every hectare of farmland with low forest cover in the steppe zone, there are 13.9 tons of humus loss, which is equivalent to 69.6 tons of organic fertilizers. In value terms, this is equivalent to about EUR 1240 ha⁻¹, which is a significant amount of damage. Increasing the forest cover of farmlands in similar natural and climatic conditions to the level of a complete system will contribute to preventing damage, reducing the loss of soil fertility by a factor of 4.

A significant item of farmers’ expenses is also the prevention of damage from the loss of crops as a result of drought and dust storms. It consists of the harvest of agricultural crops lost by land users in the future, as well as the costs of replanting these crops.

It is established (

Table 4. Damage from the loss of crops received by farmers as a result of drought and dust storms per 1 ha of farmland.

Natural Area/Farm Group	Protective Forest Cover of Arable Land, %	The Yield of the Dead Crop (On Average for 5 Years), kg	Selling Price, kg	Actual Costs of Replanting Crops	Damage to Farmers
Steppe zone:
1 ha of sunflower crops	-	760	EUR 1.2	EUR 202	EUR 1114
Group 1 farm	≈0.0	-	-	-	EUR 449
Farming 2 groups	3.8	-	-	-	EUR 120
Dry steppe zone:
1 ha of spring wheat crops	-	2000	EUR 0.5	EUR 192	EUR 1192
Group 1 farm	≈0.0	-	-	-	EUR 523
Farming 2 groups	3.5	-	-	-	EUR 176
Semi–desert zone:
1 ha of millet crops	-	600	EUR 0.2	EUR 216	EUR 336
Group 1 farm	≈0.0	-	-	-	EUR 141
Farming 2 groups	3.6	-	-	-	EUR 45

) that agro-economic damage depends primarily on the general specialization of farms. Thus, farmers incur the greatest damage when spring wheat crops die in unprotected fields in the dry steppe zone, at a value of EUR 523 ha⁻¹, which is associated with significant gross harvests of this grain crop in this zone. When cultivating sunflower, this damage is EUR 449 ha⁻¹. The contribution of protective forest plantations in reducing this damage, respectively, is EUR 347 and EUR ha⁻¹.

The smallest amount of damage is observed in the semi-desert zone, which is associated with the low cost of agricultural products (millet), despite the more expensive technologies used in its cultivation—the costs required by farmers to replant this crop compared to other natural zones are 7%–13% higher.

Thus, the economic efficiency of agroforestry in the form of reducing the damage to farmers from the loss of nutrients in eroded soils (the difference between open and forested areas) is EUR 221–910 ha⁻¹. This value decreases in proportion to the cost of zonal soils together with the initial humus content in them (r² = 99%) (Figure 3).

The economic efficiency of agroforestry in the form of reducing the damage to farmers from the loss of crops has a different dynamic—its value depends primarily on the agricultural specialization of the farm. Thus, the most profitable activity of farmers is the cultivation of cereals, in particular wheat, due to the high gross yields of this crop per 1 unit of farmland. Consequently, within the accepted conditions, agroforestry is most effective in the dry steppe compared with other natural zones.

At the same time, the overall efficiency of agroforestry (the amount of damage from loss of land and loss of crops prevented by trees) levels the amount of agro-economic damage and is subject to strict zonal dynamics (r² = 98%). The difference of this value between open and forested areas of the steppe zone is EUR 1239 ha⁻¹. In the direction of the semi-desert, the efficiency of agroforestry decreases 3.9 times, which is explained by the significant deterioration in forest conditions in this natural zone (Figure 4).

Thus, the cost expression of the effectiveness of agroforestry in adaptation to climate change is EUR 317–1239 ha⁻¹. This value is obtained from farmers by placing a forest-forming element in their fields.

3.2. Regional Computational Mathematical Model for Assessing the Effectiveness of Agroforestry in Adaptation to Climate Change, Implementing a Diagnostic Algorithm

The agroforestry model focuses primarily on the farmer’s ability to perceive and make correct decisions. However, the final decision made by him depends on the profitability of the project.

A computational mathematical model developed for the framework of this study in the form of a computer program calculates the effectiveness of agroforestry in adapting agriculture to climate change. For example, for a farm with a standard land plot size (10 hectares) (Figure 5), its value equivalent in the steppe will be EUR 12,390 (Figure 6). Of this amount, 73% is for preventing damage from loss of land fertility and 27% for preventing damage from the death of crops.

In the semi-desert, due to the worst conditions for forests and vegetation, the effect on the same area will be less—EUR 3,170. In the common structure of the prevented damage, the prevented damage from loss of land fertility accounts for almost 70% and the prevented damage from the death of crops for 30%.

In the dry steppe zone, the structure of agroforestry efficiency is somewhat different—it accounts for only 45% of the prevented damage, and 55% of the prevented damage is not accounted for. This is explained by the prevalence of the cost of gross crop production fees over the compensatory cost of zonal soil.

Thus, it is possible to automatically calculate the effectiveness of agroforestry on any area of agricultural land and preliminarily assess the potential damage that farmers will suffer as a result of climatic anomalies in open fields or which will be prevented as a result of the integration of trees into farming systems.

4. Discussion

In scientific circles, agroforestry is recognized as a strategy that can be used both for adaptation and for mitigating the effects of climate change [12,33,34]. It is estimated that trees grow on 46 percent of all agricultural land and provide for the livelihoods of 30 percent of the entire rural population [35]. The influence of tree cover on climate on a local, regional, and continental scale provides benefits that require wider recognition [36].

Evidence of how agroforestry is used as a means of mitigating the projected effects of climate change on agricultural production systems in the form of rural livelihoods, food security, and local microclimate is provided in [37]. It is noted that it provides environmental, social, and material benefits as part of livelihood in agriculture [13,38].

The agroforestry system is, along with a number of other advantages, one of the best options for combating climate change. Thus, the wood component of agroforestry systems can control land degradation, enrich biodiversity, and manage the land use system with the help of an agricultural system [39]. It has been proved that mitigating the effects of drought in the form of crop loss is solved by planting trees at a certain distance [15].

Agroforestry is a mitigating approach to reduce the impact of extreme climatic events [40]. Trees create a microclimate with a significant ability to mitigate temperature fluctuations [41] and can control the impact of the storm on crops [42].

Traditionally, mitigation of the effects of climate change via agroforestry is associated with carbon capture by trees (sequestration and reduction of net greenhouse gas emissions) [43]. At the same time, this is traditionally not the driving force of farmers’ decisions, since the land user is primarily interested in his income, and carbon uptake on farms for the sake of mitigating the effects of climate change is not attractive. In this regard, agroforestry in this context should be considered a solution to increase the yield and sustainability of existing production systems by providing an expanded range of crop cultivation options, ecosystem services, and protection of vulnerable areas from degradation. [13]. This is especially relevant where there is a regional need to find a balance between the demand for increased agricultural production and the protection of adjacent natural ecosystems from erosion [44].

Soil erosion rates are highest in Asia, Africa, and South America—soil losses on average amount to 30–40 tons ha⁻¹ year⁻¹. In the USA and Europe, these losses are less—17 tons ha⁻¹ year⁻¹ [45].

Wind erosion is responsible for more than 46% of global soil degradation in arid regions [46]. Drought is another of the main restrictions on agricultural production, which reduces yields’ maximum level [47,48]. Estimated losses of grain crops (rice, wheat, and corn) as a result of droughts over the past four decades worldwide amounted to 1820 million mg [49]. It is predicted that the losses of wheat, corn, rice, and soybeans will increase to 9%–12%, 5.6%–6.3%, 18.1%–19.4% and 15.1%–16.1%, respectively, due to the effects of drought. This increases the risk of crop loss and indicates the need to take adaptive measures to ensure agricultural production in conditions of various droughts [50,51].

Agroforestry is a mitigating approach to reduce the impact of extreme climatic events [52,53]. The most important components of climate change that are critically harmful to small farmers are fluctuations in precipitation and temperature [54]. The study showed that with a 1 °C increase in global average temperature, yields of wheat, rice, corn, and soybeans will decrease on average by 6.0%, 3.2%, 7.4% and 3.1%, respectively. In addition, these results will vary depending on crop and geographical location [55]. At the same time, it is noted in the literature that agroforestry can increase the relative humidity of the air above the fields by 7%–12%, reduce the temperature drop in the air by 1–2 °C, and mitigate the thermal stress of crops during critical periods of vegetation [56,57,58]. Thus, it can be concluded that agroforestry is able to compensate for these climate change-related losses.

While researchers and policy makers have been studying and supporting agroforestry methods in low- and middle-income countries for a long time, the recognition and promotion of agroforestry in temperate climates typical of developed countries has gained momentum only recently [59].

In the USA, agroforestry has been proven as a strategy for enriching soil and improving air and water quality, not only for landowners or farmers, but also for society as a whole [60,61]. Agroforestry in this country is recognized as a comprehensive land use management strategy [62], where windbreaks have become the most widespread [63].

There are also serious studies devoted to the assessment of European agroforestry, which is currently focused on Mediterranean, Atlantic, and continental agricultural mosaic landscapes [64]. Available publications indicate that the introduction of agroforestry techniques, as a rule, increases soil fertility and nutrient retention while reducing soil losses [65,66].

In Asia, agroforestry has played a crucial role in ensuring the livelihood of local residents since ancient times. In Southeast Asia, agroforestry covers 77.80% of all agricultural land with forest cover of more than 10%; in East Asia, 50.50%; in South Asia, 27%; and in North and Central Asia, 23.60% [67]. India and China are the flagships of the research field in terms of supportive policies and institutions [68,69]. Recent publications emphasize the role of agroforestry in providing regulatory ecosystem services, such as erosion control and climate change containment [70]. It is noted that shelterbelts can fully realize their potential in improving the microclimate in harsh environmental conditions, which is the original purpose of the construction of shelterbelts [71].

In Australia, by contrast, experts warn that traditional farming and forestry practices on this fragile continent, often imported from temperate regions in the northern hemisphere, have led to high levels of land degradation [72]. They hope that in this regard agroforestry will become more widespread in the landscape [73].

An analysis of the specialized literature on the quantitative assessment of the effectiveness of agroforestry in preventing damage to trees from wind and droughts shows that modern quantitative data are few. Most studies note the positive impact of tree systems on the quality of eroded soil and the condition of crops as a result of the effects of droughts without providing quantitative data. These works are limited to monitoring the areas occupied for agroforestry plantations [74,75,76]. Not much effort has been made to economically assess the impact of various systems of protective plantings on the quality of soil and crops, since the task is obviously difficult, and the use of various methodologies leads to ambiguous results [23]. To date, real experimental trials in agroforestry systems are still limited, but they show promising results [77].

In general, in the 2015 Ministerial Conference on the Protection of Forests in Europe, the total value of marketed non-wood forest products was calculated to be EUR 2300 million, mainly comprising plant products (EUR 1680 million). This document notes that, however, this is not easy to quantify [78].

It is possible to compare the results of our research with other values if they are obtained in natural and climatic conditions similar to Russia’s. Canada can be recognized as having these. The total value of ecosystem services provided from agroforestry in Quebec for the year was estimated at USD 2645 (or EUR 2390 at the current rate [79]) ha⁻¹ year⁻¹, of which the indirect consumer value was USD 1634 (EUR 1477) ha⁻¹ year⁻¹. At the same time, the cost of the service for providing agriculture is estimated at USD 785 (EUR 709) ha⁻¹ year⁻¹ [80], which is adequate to the estimates we have received. Climate change is expected to have a significant impact on the yield and productivity of the agricultural sector in the temperate climate zone, and multifunctional agroforestry systems are considered a potential adaptation option in this context [81].

Other available modern estimates of the productivity of agroforestry systems, as a rule, are based on the use of the Land Equivalent Ratio (LER), which compares the yield from growing two or more components together with the yield from growing them separately [74]. According to the latest reliable field data on the assessment of agronomic productivity and economic viability of agroforestry systems, the gross profit from agroforestry was lower in Denmark (EUR 112 ha⁻¹ year⁻¹) than in the United Kingdom (EUR 5083 ha⁻¹ year⁻¹) [82]. The estimates we have obtained also fall within the range of these values. In addition, they confirm the previously obtained data on the economic assessment of the effectiveness of agroforestry in preventing erosion in other natural and climatic conditions [20,23,83,84].

5. Conclusions

This study was conducted in order not only to identify but also to quantify the main advantages of agroforestry, which, on the one hand, contribute to the adaptation of agriculture to climate change, and on the other hand, will be able to interest farmers in placing agroforestry systems on their plots. It has been established that, along with carbon capture, agroforestry plays an important role in adaptation to climate change, which manifests itself in the form of preventing trees from destroying land as a result of wind erosion and the death of crops as a result of abnormal droughts.

The obtained indicators indicate that the effectiveness of agroforestry reclamation measures to adapt agriculture to climate change in all natural zones is significant. It exceeds the indicators of farms with open lands by almost a third; therefore, it could be the driving force behind farmers’ decisions. At the same time, the revealed patterns of dynamics of key indicators of agroforestry efficiency in the form of preventing damage from wind erosion and droughts show that their magnitude is not the same, but depends primarily on the soil and climatic conditions of land plots, as well as the type of specialization of the farm.

The main limitation of this study is that the proposed structure of the tools for assessing “forest reclamation” adaptation to climate change makes it possible to determine the benefits of trees only for farmers and agro-industries and, therefore, does not cover all the damages that society as a whole bears from climate change. It should also be borne in mind that for each agroforestry function, more than one assessment approach is possible, each of which will yield a different value. In addition, we found a lack of current quantitative data, since most of the studies were conducted in tropical agroforestry systems and have limited use in this study due to completely different climatic and environmental conditions. Thus, the results of the study are valuable, and the demonstrated advantages of agroforestry are significant for the temperate climate zone. The values obtained and the developed console application for their assessment can be used to raise awareness among decision makers about the need to implement policies that encourage the introduction of forest reclamation practices in pursuit of sustainable land use.

Future studies will have to enter an important stage of assessing ecosystem services (in addition to erosion and drought control) provided by agroforestry systems to the local community and regional economy. This will raise the importance of agroforestry to a new level in the country.