V.5. Monitoring the ecosystem to determine the success or failure of restoration and conservation measures.
V.5.1. Influence of the flooding and restoration process on bird population..
V.5.2. Flora
V.5.3. Use of grazing for environmental conservation


V.5.1. Influence of the flooding and restoration process on bird population.

Periodic observations on bird occurrence were conducted in the area, including the Agmon Lake, Hula Nature Reserve and surrounding fields, from January 1988 to December 2000. The purpose of the survey was to study the seasonal presence of birds in the area. The following parameters were monitored: species, habitat, number of specimens of each species, nesting data, response to management practices. Observations were conducted with binoculars and telescope along a fixed route and positions in fields and along the lake shoreline. The results are shown in Figs. 5-7.

Two of the major objectives of Life Project were to maximize the bio-diversity of animal species and to create the basis for re-establishing wildlife, principally migrating birds. As it is clear from Figs. 5-7 we succeed in this to tasks. The number of birds has increased dramatically (600%) since the creation of Lake Agmon (Fig. 5) and it seems that it will continue to increase in the coming years. It seems that this remarkable success is not only a result of the re-flooding, but could not have beeen achieved without the extensive replanting of tress for shade and shelter (see V.4.1.), establishment of windbreaks along the riverbanks. (V.4.2.) and the reintroduction of selected plant species (V.3.3.).

fig5

The re-establishment of wildlife, principally migrating birds: Migrating birds are the major species with the highest daily average (Fig. 6). Furthermore the annual fluctuation of the aquatic birds (Fig. 7) is in correlation with migration months. This two results indicate that Life Project succeeded in its second major task, which was to encourage migrating birds to stop and “refuel” in the Hula Valley while migrating toward Africa or Europe. As a result of this success, we can point to the Hula Valley and the Agmon Lake area as one of the few refuge areas between southern Europe and the wintering areas in Central Africa.

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V.5.2. Flora
V.5.2.1. Aquatic macrophytes vegetation development in the Agmon Lake.
V.5.2.2 Monitoring of plant species

V.5.2.1. Aquatic macrophytes vegetation development in the Agmon Lake.

Vegetation mapping and biomass assessment
The Lake Agmon vegetation was studied in 1994-2000 by vegetation transects, midsummer aerial photographs, GIS analysis and ground sampling (Kaplan 1998, 2000). It included a vegetation survey of plants and benthic algae classified by species in 50 sampling stations in the lake, accompanied by measurements of NPK content in plant material as well as measurements of dry weight.

Macrophyte harvesting: the annual average dry weight of macrophytes in the lake is about 270 ton (containing ca. 1 ton P). Removal of 50 ton will eliminate ca. 200 kg P. During the first year (in the northern part of the lake) and second year (in the southern part of the take) 50 ton macrophytes were harvested and removed from the lake system. The effect of this removal has been be tested by measuring changes in sedimentary P content at different depths.

The peak of submerged macrophyte biomass occurs in June-July; and by November-December all (except P. australis and T. domingensis when present) plants have degraded and disappeared. The degradation and decomposition of plant material starts in July when the benthic algae die off and continues intensively in summer-fall by macrophyte degradation. From late autumn 1994 stands of Typha domingensis were developed in Lake Agmon on the chalk-marl bottom sediments in the southern part of the lake. This vegetation became very dense during 1995-early 1996 but totally collapsed during the 2nd half of 1996. In 1998-1999 a massive renewal of Typha stands was observed in the eastern-southern part of the lake after a reduction of the water level.

To improve water quality, macrophyte removal, used as a management tool, has been tested. In 1997, 1998 and 1999, a total biomass of about 268 tons of dry weight, containing ca. 1000 kg P was measured during vegetation peak (Kaplan 1997; 1998; Kaplan et al. 1998).

The aim of the ongoing study is also to investigate the role of deep (Typha, Phragmites) and shallow (Potamogeton, Ceratophyllum, Najas) rooted macrophytes in the P cycle of Lake Agmon in order to improve water quality by mechanical removal of plant biomass. The working hypothesis is that the major available summer P source in Lake Agmon is recycled plant mediated P which can be controlled by removal of macrophyte plant material. The results are presented in Fig 8. Thus, in 1999 a total of 432 ton of macrophytes dry matter vegetation was present in the Agmon Lake, included 265 tons of the main species, Typha domingensis (Fig. 8a). The amount of mineral present was 8.8 tons of N and 0.8 tons of P (Fig. 8b).

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V.5.2.2 Monitoring of plant species
 Monitoring of spontaneous colonization of vegetation was carried out by transects established in the newly flooded area. Water depth, species composition, relative cover and phenology were recorded in monthly observations. A vegetation map of Lake Agmon is produced each year, both as data for naturalists and to monitor the lake. The results of monitoring are presented in Picture 12 and Table 3.
Lake agmon

Table 3: Vegetation Type Poligons in the Agmon Lake waters
CODE Vegetation Type Polygons in Agmon Lake Area (ha)
NP Najas minor - Potamogeton nodosus 2.1
Td Typha domingensis 4.2
CN Ceratophyllum demersum - Najas minor 8.2
NP Najas minor - Potamogeton nodosus 5.5
NC Najas minor - Ceratophyllum demersum 2.5
CNPb Ceratophyllum demersum - Najas minor - Potamogeton berchtoldii 1.5
NP Najas minor - Potamogeton nodosus 4.8
S Sterile 0.7
CPnPp Ceratophyllum demersum – Potamogeton nodosus - Potamogeton pectinatus 3.2
NPCb Najas minor - Potamogeton nodosus – Chara braunii 6.5
PNC Potamogeton nodosus - Najas minor – Ceratophyllum demersum 13.1
CPN Ceratophyllum demersum - Potamogeton nodosus - Najas minor 5.5
CPN Ceratophyllum demersum - Potamogeton nodosus - Najas minor 2.9
PN Potamogeton nodosus - Najas minor 3.3
NPPb Najas minor - Potamogeton nodosus – Potamogeton berchtoldii 4.8
PNPh Potamogeton nodosus-Najas minor – Phragmites australis 8.8
CNP Ceratophyllum demersum - Najas minor - Potamogeton nodosus 6.7
NCP Najas minor - Ceratophyllum demersum - Potamogeton nodosus 4.6
NPC Najas minor - Potamogeton nodosus – Ceratophyllum demersum 6.4
CNP Ceratophyllum demersum - Najas minor - Potamogeton nodosus 8
NPCb Najas minor - Potamogeton nodosus – Chara braunii 3.4
Cd Ceratophyllum demersum 1.6
NP Najas minor - Potamogeton nodosus 1.6
  Total area 110.10

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V.5.3. Use of grazing for environmental conservation
V.5.3.1. Measuring the carrying capacity of wet grasslands in the Hula Valley.
V.5.3.2. Use of Water Buffalo for Environmental Conservation of Wetlands
V.5.3.3. Herd of “Baladi” – indigenous Arab cattle - for the LIFE Project

V.5.3.1. Measuring the carrying capacity of wet grasslands in the Hula Valley.
 1. Introduction

The main research objective was to examine the suitability of herbivores to the peat areas of the Hula Project and the resistance of the natural vegetation to grazing. Two aspects were studied in this project: collecting data about the carrying capacity of half-dried areas and examination of the effect of grazing on the vegetation in moist habitats.

a. Carrying capacity of half-dried areas

A trial was conducted to examine the resistance of the natural vegetation to direct grazing (as opposed to harvesting). Very few (if any) data are available in this country concerning cattle, sheep, wildlife or any other grazing animal in a wet pasture. The initial hypothesis of the trials was that it would not be possible to maintain areas under plant cover without irrigation. It was found that the natural summer vegetation (especially couch grass Cynodon dactylon) covered the plots almost entirely. In previous years the soil was not covered with Cynodon dactylon as a result of annual plowing, which prevented the Cynodon dactylon from establishing a sufficiently deep root system to reach the water table, even in places where the water table was relatively shallow.

It was decided to conduct the grazing trial with donkeys, for the following reasons:
  1. It would be possible to extrapolate the results to other grazing animals.
  2. Donkeys are tranquil animals, accustomed to human contact, and in particular it is possible to bring them back to a fenced area if they break loose, unlike wild animals.
  3. There is a relatively low danger of theft and depredation, the donkey proved capable of defend themselves from jackals.

b. Examination of the effect of grazing on the vegetation in moist habitats

The aims of the trial were:a) to determine the carrying capacity an area covered by swampy vegetation. B) to study the effect of grazing in the swamp vegetation, especially on Phragmites australis, which becomes a nuisance, especially in places were it can not be eradicated by mechanical treatment. The Hula Project includes a complex of 20 ponds, measuring 20 m x 20 m each, (referred to as "the pond area").

Materials and Methods

a. Examination of the carrying capacity of half-dried areas

A 4.5 ha area was identified as the focus of research in the Hula Project. It was fenced off with an electric fence 1.20 m high, in accordance with conclusions reached experimentally in the Hula Reserve, and subdivided into two plots. The area selected was not under irrigation, but was nonetheless partly covered by vegetation, mainly Cynodon dactylon and Sorghum halepense (Table 4). At the beginning of the rainy season (November), the native winter species began to sprout, and reached a cover of 41%. The average number of donkeys used was 14. Water was obtained from two holes that were dug down to the water table.

From 15th December to 31th March the herd grazed in both paddocks, and during this date up the August 8, all the herd was concentrated in the northern paddock. During August–November the donkeys were transferred to the “pond area”. The northern paddock was defined as heavy grazing and the southern one, protected during April–August, was defined as light grazing. In the summer months, one plot was enough to maintain the herd, but in the winter, as a result of flooding in part of the area which reduced the area available for grazing and the reduction in the yield of Cynodon dactylon during the cold period, both plots were required to maintain the herd adequately.

Operation of the electric fence is problematic in moist areas, especially during the winter, because the wet vegetation shorts out the fence. Mowing and spraying were used next to the fence, to prevent the vegetation growing too high. The donkeys learned to recognize the fence and did not break out, in spite that sometimes the voltage was low, because of the problems of charging and of dew on the wires.

b. Examination of the effect of grazing on the vegetation in wetlands.

The "pond area" was fenced off with an eight-strand electric fence, 2 m high. In this newly defined area, surveys were conducted to determine the composition of the vegetation before grazing commenced. The plot was planned for Persian Fallow Deer, planned to be transferred from the Carmel Nature Reserve, but because of lack of certainty regarding the future of the project area; it was decided to conduct the trial with donkeys.

According to results of the preliminary survey five habitats were defined in the pond area:
  1. Dry areas. Dominated by Sorghum halepense, Cyperus rotundus, Cynodon dactylon and Polygonum arenastrum. During winter is covered by winter annuals as Triticum vulgare, Phalaris sp. and Polypogon monspeliensis.
  2. Shallow ponds, dry in summer: Cynodon dactylon and Phragmites australis dominated the area.
  3. Banks around flooded ponds: A dry area, 50% Cynodon dactylon, with the remaining 50% held mostly dried-up annuals. Phragmites australis dominated the slopes.
  4. Deep flooded ponds: These were found to be covered 60% by water and 40% by vegetation, Typha domingensis (60%), Phragmites australis (25%) and 15% Potamogeton nodosus.
  5. A shallow pool, half-full all year round that was used as a control (without grazing). Natural species established themselves in the pond: Cyperus rotunduss, Scirpus maritimus and Juncus bufonius.

c. Vegetative yields and nitrate content
Periodic harvesting of the vegetation was conducted in 10 squares of ¼ m2 in each paddock. The samples were dried at 65°C and their dry weight was determined. Samples of harvested material were analyzed to determine their nitrate content and the chemical composition of Cynodon dactylon, the major component of the material.

4 Results

a. Carrying capacity of half-dried areas

It would appear that the capacity of half-dried pasture to carry herbivores is especially high. The donkeys maintained themselves without supplementary food at a pressure of 0.15 ha/head in summer and 0.3 ha/head in winter, which is higher than estimated before the trial. The donkeys proved themselves an efficient tool for the implementation of these grazing trials, providing us with the information required on plant response to grazing and the carrying capacity of the land. The influence of grazing on the composition of the vegetation expressed itself in a decrease of cover by Sorghum halepense under heavy grazing (Table 4). In the absence of grazing, the cover of such species as Sorghum halepense and Cyperus rotundus increased.

b. Examination of the influence of grazing on vegetation on moist habitats

As regards the carrying capacity of each plot of pasture, results were similar to those obtained from partly dried-out areas, except that the capacity was higher. The donkeys showed a clear preference for herbaceous vegetation. During the summer months the donkeys grazed predominantly on Cynodon dactylon, but when it froze, the grazing pressure shifted to Sorghum halepense. In this trial the grazing pressure was not enough to reduce the dominance of Phragmites australis. Cyperus rotundus is palatable and its cover decreased under heavy grazing and due to competition with taller species, such as Phragmites australis.

c. Vegetative yield and nitrate content

Before the commencement of the trials, it was feared that the level of nitrates in the plants would poison the grazers. However, the nitrate content was 0. 1 - 1.0 %, which did not affected their health.

Table 4: Changes in botanical composition under donkey grazing [%]
Paddock     South Paddock
Moderate Grazing		 North Paddock
Heavy Grazing
Date 15/1 31/3 15/6 15/6
Cynodon dactylon 26 45 75.2 77.8
Sorghum halepense 6 15 12.2 2.7
Winter annual vegetation 41 24 0 0
Bared Soil 5 8 8.8 17.5
Amaranthus blitoides 0 0 0.8 2
Cyperus rotundus 0 0 3.1 0
Water covered soil 22 8 0 0
Total 100 100 100 100

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V.5.3.2. Use of Water Buffalo for Environmental Conservation of Wetlands
1. Introduction
a. Grazing effects on wetlands structure and botanical composition.
It is clear up to now that livestock have multiple effects on wetlands, which can be beneficial, if overgrazing is avoided. Important also is the system of grazing. Planned grazing systems adapted to the condition of each wetland seem to be more effective in harmonizing, livestock husbandry and wetlands than continuous grazing (Duncan and D'Herbes, 1982, Skovlin, 1984). Also, the species of livestock should be considered, even to the point of specific breeds. Sheep and goats do not like the water and often develop worm and foot problems. Cattle, on the contrary, freely walk in the water, as do horses. According to Gordon et al. (1990), some cattle and horse breeds have developed special morphological adaptations for grazing in water, such as inflated homs, broad hooves or small bodies so that they can easily walk in wetland habitats.
water buffalo
Grazing as a management tool in wetlands has received little scientific attention in the past, apparently because of the detrimental effects of overgrazing on the environment. Livestock has been removed from most wetlands and other natural reserves, including forests and policies hostile to livestock husbandry have developed. Most of these ecosystems evolved with the presence of farm animals including buffaloes, thus leading to a peaceful coexistence. However, this coexistence has already been broken because of the expansion of cultivated fields in the old marshlands, which led to the reduction of the available grazing lands and finally, to the overgrazing of the remaining wetlands. In the meantime, cattle replaced buffaloes in the majority of wetlands due to socio-economic changes. The impact of livestock on wetlands can be aggravated or mitigated, depending on the management practices applied. Livestock grazing affects the canopy and species composition of wetland vegetation, but its impact depends on its intensity. If it is severe, plant reproduction is prevented and complete elimination of vegetation may result, with adverse effects on the aquatic environment.

Riparian vegetation, in particular, stabilizes the stream banks, regulates the temperature in the water, reduces sediment and nutrient transport and, if woody, it can remove nutrients from sub-surface flow and store them. Overgrazing of such a vegetation results in the reduction of shade and cover which may raise water temperature and eliminate the sensitive fish species (Platts, 1979). Also, it may cause soil and stream bank erosion, increased soil water evaporation and a rise in water temperature which will increase, with the additional light, the growth of algae and hence lead to the destruction of fish habitats (Skovlin, 1984).

b. Influence of grazing on avian habitats

As far as the effects of livestock on wetland birds are concerned, they depend on where a particular bird feeds or nests and on the grazing season (Skovlin, 1984). In general, the effects may be direct or indirect (Tsougraids, 1995). Direct effects mainly refer to trampling of nests by large animals, such as cattle and, rarely, to egg consumption by sheep. A kind of positive interaction has developed between livestock and some bird species, such as Bubuicus ibis and Molothrus spp. Deferment of grazing during the reproductive period can overcome damaging effects of livestock on nests.

Indirect effects are caused by changes in the structure and composition of vegetation. In general, livestock grazing increases the number of invertebrates, birds and vertebrates of the open habitats, while it decreases the species of the closed habitats. A case in point is reedbeds, which are dominated by Phragmites australis and cover larger areas in several wetlands. These communities are poor habitats for both fish and most species of wetland birds. A reduction in cover of these macrophytes in the freshwater marshes of Camargue in Southern France was found to increase the population of the two duck species, Anas crecca and A. strepera, by 2 to 11 times. On the other hand, overgrazing of macrophytes, such as Scirpus maritimus, may result in the reduction of another duck species (Anas platvrhynches) which feeds on its seeds (Duncan and D'Herbes, 1982).

Among all livestock, water buffaloes are the most adapted species to the wetland environment. It is a grazer like cattle, but it can stay longer in the water and utilize more efficiently wetland vegetation, especially emergent macrophytes like Phragnites australis. Also, it is not affected by worm and foot problems. However, little research information, if any, is available on the role of water buffaloes in wetlands as compared to the other livestock species.

c. Water buffaloes in the Hula Valley.

The water buffalo (Bubalus bubalis) was domesticated in India and brought to the Middle East in the 7th Century C.E. With the draining of the Hula swamps in the late 1950s they disappeared from the Hula Valley. In 1968 a herd of 87 head was reintroduced to the Hula Nature Reserve, established after the drainage in a small part of the valley (Frenkenberg, 1991). Today the herd numbers about 110 adults. The buffalo were maintained at high stocking rate so as to control the growth of woody vegetation, particularly Tamarix jordanis, and to ensure the opening of thickets and the establishment of meadows (Kaplan and Vaadia, 1993). The purpose of the trial was to determine the carrying capacity of desiccated swamp lands in the Hula Valley for buffalo grazing.

2. Materials and Methods

In a previous trial, in 1985, buffalo grazing was confined to a paddock of about 1.6 ha maintained predominantly for visitors to the Hula Nature Reserve meadows (Kaplan and Vaadia,1993) (Paddock No.1). The same paddock, continuously grazed, was used in this trial. A second paddock (Paddock No.2) was established next to Paddock 1 in an area of 2.8 ha, fenced off with a solar-powered electric fence.

In August 1997 15 head (13 females and 2 males), all about one year old, were selected for the grazing trial, and enclosed in a corral for a period of one month to acclimatize, become tamer and accustomed to human contact. These animals were introduced into Paddock 2 and remained in the paddock throughout the trial, at a stocking rate of 0.2 ha per animal. About eight head grazed continuously in Paddock 1 from 1986 until the end of the trial.

The average animal weight was 130 kg at the beginning and 230 kg at the end of the grazing trial. The physical shape of the buffalo determined by visual estimations, scoring from 1 (bad) to 5 (excellent), was good, fluctuating from 3 to 4 for most of the year. The stocking densities were calculated according to the herbaceous biomass at the beginning of the grazing season. The herbage consumption rate was estimated at 2.5% dry matter per kg of animal live weight and a 3% daily growth rate for the herbaceous vegetation.

The botanical composition of the paddocks was determined by surveys conducted along permanent transects 100 m long, one in each paddock. The species cover was estimated in 7 quadrats of 5 x 5 m along each transect. The herbaceous biomass was measured by clipping samples from 50x50 cm plots. Plants were clipped at a height of 2.5 cm with hand clippers, using a wire frame. The total harvested material of each sample was collected, dried at 65oC for 48 h and then weighed by an analytical balance with 0.1 g precision.

3. Results

The botanical composition in Paddocks 1 and 2 is shown in Table 5. The principal species were Cynodon dactylon, Paspalum paspaloides, Xanthium strumarium, and Trifolium fragiferum. Xanthium strumarium was not grazed by the buffalo, but covered large parts of the Paddock 2, were it was mowed twice during the summer months. This treatment was enough to control this plant. In Paddock 1, Cynodon dactylon was dominant in summer and Trifolium fragiferum was especially prominent in spring. In Paddock 2, Pennisetum clandestinum invaded and suppressed Cynodon dactylon.

The biomass in Paddock 2 is shown in Fig. 10. The herbaceous standing biomass varied throughout the year (Fig. 10), fluctuating between 1200 and 1800 kg/ DM/ha during spring, summer and autumn, and dropping to around 400 kg/ DM / ha in winter. At the end of November the biomass fell below the threshold that allowed the animals to graze to satiety.

Table 5: Botanical composition under heavy water buffalo grazing in dried Hula Swamp.
Survey date 14/11/93 31/05/94 9/8/1994 24/11/94 26/06/95 26/07/95 7/11/1995
Cynodon dactylon 82.5 45 62.5 81.7 39.2 57.2 82.5
Xanthium strumarium 0 0 0.4 0 0 0 0
Trifolium fragiferum. 1.3 38.3 11.8 7.5 30.3 15.8 5.7
Paspalum paspaloides 0 0 5.5 5 8.3 0 0
Other species 12.2 14.2 17.2 0.8 20.7 25 8.5
Bare soil 4 2.5 2.6 5 1.5 2 3.3
Total 100 100 100 100 100 100 100

a. Paddock 1: Continuous heavy grazing from year 1986

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4. Discussion

A grazing trial was conducted for two years at a very heavy stocking rate (4.6 head per ha) for a non-irrigated natural pasture. Only during the late autumn and winter the growth rate of the vegetation decreased to the extent that it was necessary to supplement the livestock with hay. According to trials conducted in the region, the estimated growth rate of the pastures is about a 3% daily growth rate, in relation to the standing crop (Kothman et al., 1995). According to the National Research Council (1984) 2.5% dry matter of the animal live weight is considered as the potential daily intake.

Accordingly to calculation with the above figures, the pasture growth rate was above the consumption rate during most of the year. Only at the end of November was the animals consumption rate above the vegetative growth rate, and the biomass standing crop fell below the threshold that fulfilled the animals’ requirements. The botanical composition in Paddock 1 varied during the year, but the dominant species persisted and fluctuated in a regular pattern (Table 5). After 9 years of continuous heavy grazing, no herbaceous or woody invaders were registered. In Paddock 2 grazing prevented the invasion of woody species, but the herbaceous weed Xanthium strumarium had to be suppressed by mechanical mowing. The botanical composition was more “turbulent” than in Paddock 1, possibly because of the shorter grazing history.

Results from both paddocks indicate that heavy continuous grazing on the drier areas of the drained Hula Swamp, at a stocking rate of 0.2 to 0.33 ha per buffalo, induced an open, vigorous pasture swards.

V.5.3.3. Herd of “Baladi” – indigenous Arab cattle - for the LIFE Project
 A herd of “Baladi” (indigenous Arab cattle) was collected for the Hula Nature Reserve. The herd grazes a relatively poor area of pasture, consisting mostly of reeds, such as abounds in the Hula Valley and the vicinity of Lake Agmon. This poor pasture is suitable for Baladi cattle, but less so for the water buffaloes that have been introduced into the Nature Reserve. Due to the crossing with modern more productive breeds, the Baladi almost disappeared from Israel and the Palestine Autonomy cattle herds.

In the framework of the Safari Plan of the re-flooded area, it is important to diversify the animal species introduced. Baladi cattle fill an important niche in the types of pasture available. A pioneer pilot project, involved a herd of about 50 cows and 3 bulls, was carried out to test the ability of these cows to utilize wetlands that are highly susceptible to wildfires in the summer when ungrazed. Observations of their grazing habits and behavior are also being conducted. In addition, the herd was selected according to morphological criteria, by which herds of this variety have been adapted over hundred of years to local conditions. The result has been that the Baladi is strongly disease-resistant, protects its young against predators and can exploit both overgrown and thinly covered habitats, with such plants as Phragmites australis, Rubus sanguineus, Ricinus communis and even Tamarix jordanis.

So far the cattle proved resistant to ticks. Despite the fact that the herd has not been sprayed for a period of three years, no signs of infestation have been observed. Most of the cows, even the oldest ones (more than 12 year olds), succeeded in raising one calf per year. No feed supplements are provided and the only food available is the natural pasture. The fact aroused the interest of cattleman; the Galilee Agriculture Research and Development have purchased a herd of 19 heifers as a result of this trial, with the aim of testing the disease resistance and productivity of Baladi crosses.

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