Months In Winter Research Articles

Soil nitrogen dynamics in northeastern Patagonia steppe under different precipitation regimes

Small-scale heterogeneity of plant cover and highly variable precipitation events in dry regions can strongly influence N dynamics. We evaluated the differences in N availability (Ni), N mineralization (Nmin), flush of microbial-N (N-MF) and soil moisture (SM) at 0–20 cm depth among four types of patches characteristic of heavily grazed areas in the northeastern Patagonia steppe of Larrea divaricata and Stipa spp. Soil samples were taken monthly during two years of differing annual precipitation (178 mm in 1994 and 325 mm in 1995). Ni and SM were also measured at 20–40 cm depth. Additionally, we estimated the potential N mineralization (pNmin) during two months in both winter and summer in laboratory incubations at 20% soil moisture and 25°C. Sampled patches included: undisturbed patches of shrubs and perennial grasses (GSP), incipient patches of Larrea divaricata and perennial grasses (IGSP), incipient patches of the perennial grass Stipa tenuis (GP), and bare soil (BS). Mineralization rates were much higher during the wet year, and higher in GSP and IGSP than in GP and BS. The prevailing form of Ni was NH4+–N, but pulses of NO3-–N were measured in field incubations when SM was higher than 10%; NO3-–N was also the main form of Ni in pNmin assays. Flush of microbial-N depended mainly on plant cover, following the sequence: GSP>IGSP>GP=BS. It was not correlated with soil moisture, except in the GSP patches, and exhibited lower values during the wet year. Available N (as NH4+–N) was higher in the subsurface than in the surface samples during the wet year. The relative importance of N-MF and Nmin as indicators of spatial and temporal changes in N dynamics, and the role of deep-rooted shrubs in the recovery of soil N fertility, are discussed.

Natural Control of the Cereal Stemborers Busseola Fusca and Chilo Partellus in South Africa

The stemborers Busseolafusca (Fuller) (Lepidoptera: Noctuidae) and Chilo partellus (Swinhoe) (Lepidoptera: Pyralidae), are the most important pests of maize and grain sorghum in South Africa. Parasitoids, pathogens and predators curtailed populations of B. fusca and C. partellus on the crops but their activity was not enough to reduce pest populations to below-economic-damage levels. They also could not prevent the dispersal and subsequent widespread distribution of C. partellus after its introduction into South Africa. Nine parasitoids and hyperparasitoids have been recorded attacking both borer species. These parasitoids are probably more habitat-specific with regard to foraging for hosts than they are host-specific, as they appear to have moved from their indigenous hosts to use C. partellus as a new alternative host. Between 1977 and 1993 three braconids, one eulophid, three ichneumonids, two trichogrammatids and four tachinids were introduced into South Africa from 11 countries for biological control of stemborers. Recoveries of parasitoids were made only short periods after releases and in the vicinity of the release sites. Cold and dry winters, with night temperatures often falling to below freezing, prevail in the Highveld Region which is the major summer-grain-producing area of South Africa. These conditions, and the fact that borers enter diapause in the dry stalks for 7 months in winter, when the crops or other alternative host plants such as grasses do not grow, hamper the establishment of exotic natural enemies in the Highveld Region.

Phosphorus in runoff from a fertile dairy pasture

Losses of phosphorus (P) from grazed pastures in runoff can significantly reduce the water quality in streams draining agricultural catchments. Many preventative strategies depend for their success on the association of the P with large soil particles (>0·45 mm). We investigated the forms of P in runoff from a dairy pasture of high fertility. A 3·6-ha paddock at Darnum in West Gippsland, Victoria, was set up to measure runoff volume and rainfall, and to sample runoff water. Runoff from the site was restricted to 3 months in late winter and spring. Total runoff for 1994 of 660 m3 had an average total P concentration of 5·2 mg/L. Runoff from a single storm system over 8 days in early November accounted for 56% of the total runoff volume and 69% of the P lost. Of the total P in the runoff, 93% passed through a filter with 0·45-µm pores and 91% was reactive in an ascorbic acid–molybdate medium, without digestion; 89% of the P was both reactive in the ascorbic acid{molybdate medium and in the <0·45-µm fraction. There was no apparent relationship (P > 0·05) between P concentration and soil cover. In the Darnum catchment, the major runoff events occurred when the soil was saturated. The low settling velocities of materials <0·45 µm and the amount of P moving in larger storms would suggest that buffer strips and riparian zones are unlikely to decrease P losses substantially from dairy pastures in this area. Further, since erosion is unlikely to be the major process by which P is lost, control measures which simply limit erosion will be similarly ineffective at preventing P losses under the conditions that prevailed in this study.

Changes in streamflow components following logging and regeneration in the southern forest of Western Australia

Two small experimental catchments were established in the south-west of Western Australia to study the effects of logging and subsequent regeneration on the mechanism of streamflow generation. Following a six year pre-treatment calibration period (1976–1981), one catchment (March Road) was logged and reforested in 1982 and the other (April Road South) remained as a control. Logging resulted in an increase in groundwater levels and subsequently groundwater discharge area. The deep, permanent groundwater levels in the valley and upslope areas rose until 1986 and then began to decline. The maximum rise was 5 m in the upslope areas. The duration of shallow, intermittent groundwater system, perched on underlying clay, was extended from 2–3 months in winter before logging to 5–6 months after logging. The shallow groundwater level rose in the valley and began to discharge at the ground surface in 1986. Logging resulted in an increase in streamflow. The maximum increase (≈18% of annual rainfall) was in 1983, one year after logging. The increase in streamflow was due to a substantial decrease in interception and evapotranspiration, increased recharge to the shallow groundwater system, decreased soil moisture deficit and consequently an increase in throughflow. The increase in base flow was about twice that of quick flow. The changes in streamflow and its components in the subsequent years were closely related to the groundwater discharge area. Most of the quick flow was generated as saturation excess overland flow from the groundwater discharge area in the valley. The expansion of the groundwater discharge area, increased soil moisture content, higher groundwater level and the presence of the shallow groundwater system for the extended periods were responsible for the process of streamflow generation.

The Timing of Breeding by Zebra Finches in Relation to Rainfall in Central Australia

SummaryZebra Finches Taeniopygia guttata are renowned for breeding opportunistically in arid Australia and for their ability to nest immediately in response to rain at any time of year. However, this conclusion has rested on short-term and incidental observations. We monitored breeding of Zebra Finches at Alice Springs, central Australia, over a seven-year period by estimating the month of hatching of free-flying subadults caught at a walk-in trap. Capture-mark-recapture analysis suggested that the monitored population was open and highly mobile and exploited a large home range. Despite gaps in the sampling a multiple regression analysis found a significant statistical relationship between breeding and the incidence of rainfall. When conditions were favourable in a given year Zebra Finches had a very long reproductive period with 10.6 equally good consecutive months for breeding. Breeding was possible in every month of the year but was least in April and greatest in October. Low winter temperatures did not prevent breeding. The heavier the rainfall, the more intense and the longer the breeding episode. Once a breeding episode began, surges of breeding activity corresponded with follow-up rams. We did not observe the immediate response to rainfall described by earlier authors. On the contrary, the statistical analysis revealed that rain had a negative effect on breeding in the month in which it fell, and in the following month. There was a lag between the onset of the first rains and the onset of breeding, ranging from one to two months in summer to two to three months in winter. The statistical analysis revealed that rain four months previously had the most profound positive effect on breeding. Hatching of the first clutches coincided with the first availability of ripening grass seeds. The artificial supply of abundant dry seed, on its own, did not stimulate breeding. The timing of seed set by grasses in central Australia is complex, depending on the species composition, the prevailing temperatures immediately after rain, and the amount and timing of previous falls of rain. We suggest that Zebra Finches track these factors and breed opportunistically as soon as new supplies of seed are available.

Mixing entropy analysis of dispersal of aircraft emissions in the lower stratosphere

A trajectory calculation is used to compare the characteristic time for northern midlatitude aircraft emissions to disperse during both summer and winter. The mixing process is summarized by the time evolution of the “mixing entropy,” which is proportional to the number of ways of partitioning N parcels over M equal area subregions of the hemisphere. The mixing entropy is a measure of the disorder in the parcel distribution and quantifies the approach to a spatially uniform state as time increases. We show that the time for a single release of exhaust to become mixed down to length scales of the order of 800 km is about 2 months in winter and at least 4 months in summer. We also examine the time evolution of the mixing entropy of emissions from a continuous source over two 6‐month periods starting in January and June. For a single continuous source, which represents a persistent and highly asymmetric perturbation, we find that the horizontal distribution of the total emissions reaches a mixing steady state in 6–8 months. On this timescale the mixing entropy is close to the maximum value, and the likelihood of large temporal fluctuations becomes small. The dependence of the mixing on the location of the source and the effect of multiple flight paths on the overall uniformity of the spatial distribution is also considered.

Spectral Budget Analysis of the Short-Range Forecast Error of the NMC Medium-Range Forecast Model

The budget of the systematic component of the short-range forecast error in the National Meteorological Center's Medium-Range Forecast Model (NMC MRF) is examined. The budget is computed for the spectral coefficients and the variances of vorticity, divergence, virtual temperature, and specific humility at every time step during the 24-h model integration. Two months in winter and three months in summer, totaling 150 cases, were integrated with the budget diagnostics. The results of the budget of the spectral coefficients—that is, the budget of mean error—showed compensation among large terms except near the model boundary; therefore, it is difficult to point to a significant source of the systematic error in the free atmosphere. Near the model lower boundaries, dynamics cannot fully compensate physical forcing, and estimation of some physical processes responsible for the mean errors is possible. In contrast, the budget of the variance of the coefficients—that is, the energy budget—is more interesting and informative. The most apparent problem found in the model is a loss of rotational kinetic energy in the medium (total wavenumber n = 11–40) and small (n = 41–80) scales in the free atmosphere. About 50% of the loss is explained by the excessive horizontal and vertical diffusion. There is a strong indication that the rest of the loss of kinetic energy is related to the insufficient generation of available potential energy in the medium scale. To isolate further the cause of the error in the energetics, several forecasts with budget diagnostics were performed. The experiments showed complex interactions between the physics and dynamics and among the different physical processes. Particularly noteworthy are (a) the compensation between horizontal and vertical diffusion and (b) the balance among horizontal/vertical diffusion, the barotropic scale interaction, and the baroclinic conversion terms in the rotational kinetic energy equation. The results of this study guided the design and implementation of changes in the NMC model in the horizontal diffusion and the cumulus parameterization.

九州北部及び隣接地に於ける近世棟札の内容 : 主文と工事時期

Since 'munafuda's (dedication boards) are usually written at the time of putting up the ridge-beam of holy buildings. 'joto tatematsuru' (we dedicate this building in deep reverence) might be the most appropriate description. In actuality, however, this description constitutes only few percentage. According to these munafudas, these percentages show that the peak of the constructions was under way March and Spring, and August and September. But since the dates were written at the time of dedicating the building, we must assume that the construction works were already under way in spring, or further back in winter and summer, sometime during the off-season on the farm; that is, after the harvest and before the rice-planting time. In this conection, 'Daisho-tekagami' mentions, "January, July, October, November, and December are auspicious months for building a pole of the sate" ; meaning that the three months in winter except January and July correspond to the slack season on the farm when more helping hands are available.

Seasonal development of leaf area in a young, widely spaced Pinus radiata D. Don stand.

Measurements of needle elongation and needle death were made at two-week intervals during a year on 250 branch units spread throughout the crowns of six trees (three high-pruned, three low-pruned) in a widely spaced, 6- to 7-year-old Pinus radiata D. Don plantation in New Zealand. The trees were well supplied with nutrients and water. During the year, mean tree height increased by 1.2 m and the cross-sectional area of stem below the green crown (used to predict leaf area) for the average tree increased from 8.7 x 10(3) to 13.9 x 10(3) mm(2). The increase in stem cross-sectional area occurred throughout the year except for two months in early winter (May and June). Elongation of Age 0 needles began in Spring (October), continued through summer, and the mean date for 95% completion of elongation was in autumn (early May), approximately 200 days after elongation began. Mean maximum needle length in the canopy decreased with increasing branch order and was 136 and 94 mm for Order 1 and Order 3 units, respectively. Needle elongation was related to thermal time, using growing degree days with a base temperature of 6 degrees C. The mean maximum rate of needle elongation in the canopy was 0.11 m ( degrees C day)(-1) and this occurred in early summer (mid-December), 47 days after elogation started. Maximum needle length and the rate of elongation increased, and the time taken to reach 95% elongation decreased with increasing height in the canopy. A smaller autumn flush of needles started in summer (January) and the needles elongated linearly at a mean rate of 0.07 mm ( degrees C day)(-1) until the end of the growing season when temperatures fell below the base value. At the end of the year, the mean length of needles from the autumn flush was 66 mm. The density of needles did not change with height in the canopy and there were no significant changes seasonally. The mean density values for Age 1 and Age 0 needles were 336 and 286 kg m(-3), respectively. Dry weight per unit length did not change seasonally for Age 1 needles, but the mean values for Order 1 and Order 2 needles were 0.32 and 0.23 mg mm(-1), respectively. Dry weight per unit length for Age 0 needles increased during the growing season (October to February). This was particularly apparent for Order 1 needles where the mean value increased from 0.12 to 0.25 mg mm(-1). Death of Age 1 needles started in midsummer (mean date was January 24) which coincided with the time of maximum elongation of Age 0 needles, but there were differences in timing among individual trees. The mean rate of death was 1.7% day(-1) and the mean duration was 59 days. Leaf area index for the stand increased from 3.2 to 5.3 (all-surfaces basis) during the year. At the end, 92% of the leaf area had grown during the year and 60% of it was on Order 2 branch units. The models for needle elongation and needle death were used to scale up to seasonal changes in canopy leaf area index. Leaf area index peaked with increasing Age 0 leaf area to 6.1 in summer (January), fell to 4.7 in March as Age 1 needles died, then increased slightly again. The seasonal dynamics are consistent with the hypothesis of Cannell (1989) that the timing of maximum leaf area index within a year is optimal for maximizing biomass production.

Comparison of ecophysiological responses to heavy snow in two varieties of Aucuba japonica with different areas of distribution

AbstractAucuba japonica varieties are common evergreen understory shrubs in Japan. Aucuba japonica var. borealis is distributed on the Sea of Japan side of Honshu and Hokkaido where heavy snow cover lasts for more than 3 months in winter. Aucuba japonica var. japonica is distributed in areas with shallow or no snow on the Pacific Ocean side of Honshu and Shikoku. The ecophysiological characteristics of var. borealis were compared with those of var. japonica to examine the effects of heavy and long‐term snow cover on the life cycle of var. borealis. Shoots of both varieties were shaded in crushed ice for 110 days, but their photosynthetic activities, chlorophyll contents and the chlorophyll a/b ratio was not affected. The leaves of var. borealis were no less frost tolerant than those of var. japonica. In spite of the difference in environmental factors, both varieties had similar characteristics in seasonal changes of photosynthesis, respiration and chlorophyll a/b ratio. These results suggest that var. japonica could survive in areas with heavy snow where it does not normally occur. Leaf net production (LNP) was estimated based on the microclimatic data and seasonal photosynthetic and respiration rates. The difference in the annual LNP between the two varieties was equivalent to the difference in the LNP during the snow season. One of the major effects of snow cover is to interrupt and reduce the production period of var. borealis.

Comparative fuel metabolism in Gentoo and King Penguins: adaptation to brief versus prolonged fasting

To compare fuel utilization in large birds adapted to brief or prolonged fasting, protein and lipid utilization were quantified in the Gentoo Penguin (Pygoscelis papua) and the King Penguin (Aptenodytes patagonica). The inshore feeder Gentoo Penguin fasts for only a few days in its colony, while King Penguin chicks starve for several months in the subantarctic winter and male King Penguins starve for 5–6 weeks at the beginning of their breeding cycle. After an initial decrease in both daily body mass loss and nitrogen excretion during the first days of food deprivation, these two parameters thereafter stabilized at low values. At that time, protein utilization accounted for 15% of total energy expenditure in Gentoo Penguins and only 6% in King Penguin chicks during winter, the remainder (85% and 94%, respectively) being provided by fat oxidation. Similar percentages in fuel metabolism as seen in chicks during winter were reached in fasting adult King Penguins and spring chicks. However, a seasonal adaptation occurs in fasting chicks because energy expenditure is lower during winter. As previously described in starved mammals, the effectiveness in protein sparing could be related to the initial adiposity of the birds: the larger the fat stores (about 9% and 30% in Gentoo Penguins and winter chicks of King Penguins, respectively), the longer the fast duration and the better the level of protein conservation.

Prospects for Improving Mediterranean Grasslands in Lebanon through Seeding, Fertilization and Protection from Grazing

SUMMARYGrassland productivity was studied for four years near Terbol, Lebanon. In the first year pasture availability and plant numbers were monitored along transects, and in the following three years the effects of sowing four Mediterranean annual legumes (three cultivars of subterranean clover and a local ecotype of Medicago rigidula) and top-dressing with super-phosphate were studied. The results indicated that natural grasslands were dominated by annual grasses (Aegilops, Hordeum, Bromur, Lolium and Poa). Legume density was low, which resulted in poor legume productivity, especially in winter. Exotic legumes only resulted in a slight improvement in pasture productivity even when phosphate fertilizer was added. However, partial protection from grazing (for one or two months in late winter and spring) more than doubled the number of legume seeds in the seed bank compared with full protection and open grazing. The build up of seeds in the soil is an essential step towards the improvement of productivity in these degraded pastures, which form a large part of the land surface in Lebanon and on which small ruminant production largely depends.

期間実測値による多数室室温・熱負荷計算法の暖房期についての検証

This paper describes the validation of the proposed simulation method using the field test data obtained from the two experimental houses for the three months in winter. From the comoarison between the simulated results and the measured data the following were found. The disagreement between the simulated values and the measured values are 10 % for the seasonal heating loads. The room air temperature variation obtained by the simulation and the measurement showed similar orofiles and good agreements. From these results it was concluded that the proposed method can be used for predicting the thermal oerformance of residential buildings.

Occurrence of Bivagina tai (Monogenea:Microcotylidae) on the gills of cultured red sea bream Pagrus major.

Occurrence of a gill monogenean Bivagina tai was monitored monthly on a single stock of red sea bream Pagrus major artificially spawned and cultured in a net cage. The monogenean was found from the fish stock all the time except for the first few months, significantly in greater numbers on the first gills than on the others. The infection fluctuated with seasons. There were three peaks of infection during the two-year study period. The O+ fish had the highest level of infection in winter, but the infection was modest in the next winter, suggesting the peak infection resulted from lowered resistance of the small fish to infection at low temperatures. A second and a third peak of infection were formed in May, when the fish was just one and two years from hatching; the rise of water temperature was probably responsible for the peak formation. From the seasonal changes in the development of B. tai, using the clamp number as an in-dicator, it is deduced that the monogenean had three, possibly four, generations a year. The life-span is estimated as 3-5 months in winter and as 2-3 months in spring through autumn.

The leukocyte system in rainbow trout, Salmo gairdneri Rich. affected by prolonged subacute phenol intoxication

The paper gives a quantitative and qualitative analysis of leukocytes in the peripheral blood, spleen, and pronephros of rainbow trout affected by phenol intoxication (2 mg phenol dm-3 applied for 2 months in winter).

DISTRIBUTION, SEASONALITY AND REPRODUCTIVE PHENOLOGY OFBANGIA ATROPURPUREA(RHODOPHYTA) IN RHODE ISLAND, U.S.A.1

ABSTRACTForty‐seven sites along the Rhode Island coastline were sampled on a seasonal basis for the presence of the red algaBangia atropurpurea(Roth) C. Ag. This species was found to be widely distributed, occurring at 94% of the hard, stable substrates sampled.Bangiapopulations were most, widespread in the winter (71% of sites) and least frequent in the summer (29% of sites). At one location, three high intertidal populations (average height 101 cm) and three low intertidal populations (average height 14 cm) were sampled monthly for two years. The upper intertidal populations appeared in September and persisted until at least May, whereas the lower populations were ephemeral, appearing for only a few months in late winter. The high intertidal populations were present on 85% of the sampling dates white the lower ones were observed on 25% of the sampling dates. Upper intertidal filaments reproduced exclusively by asexual monospores unlike those of the lower populations which were largely sexual. The maximum diameter of asexual and carpogonial filaments was 120 and 250 nm, respectively. Monosporagenesis was strongly correlated to temperature whereas gametogenesis was strongly correlated to photopriod.

Growth of the Colony and Maturation of Zooids of a Bryozoan Bugula neritina in the Sea

The larvae attached on slide glasses were immersed two meters below the surface at two stations in Omura Bay and Nomo Inlet located near Nagasaki City. Colonial growth shown by the increase of zooid number, sexual maturation and the time span of the colony from attachment on to falling off from the slide glass (life span of the colony) were investigated in four seasons from 1982 to 1983.There was a linear relation between the number of zooids (N) and the height (Hmm) of the colony, which was represented as follows: ln N=2.46 ln H-0.22 (r=0.96).The lowest temperature for survival of the colony and the lower limit of temperature for the exponential growth were estimated as about 9°C and 13°C, respectively. The life span of the colony varied from 1.5-2 months in spring and summer to more than 3 months in fall and winter, depending on water temperature.We could observe the first brood chamber in zooids when the colony had grown up at zooid number of 200-1, 000. Our observation suggested that the colony could release the larvae after growing up at the zooid number of 1, 000 to 5, 000 (height, 2-4cm). The minimal size of the colony in sexual maturation showed little fluctuation seasonally in zooid number.The maximal size of a colony was estimated as 20, 000-50, 000 in zooid number (height of the colony, 6-10cm).

Ambient temperature dependence of the body temperature and of the duration of the hibernation periods in the garden dormouse, Eliomys quercinus L

Hibernation pattern in the garden dormouse ( Eliomys quercinus) was studied at T A's of 0, 4, 6.5, and 9 °C during 6 months in each study winter. The animals were kept in darkness without food or water. Body temperature and the mean duration of the hibernation periods were ambient temperature dependent. The comparison of hibernation at different T A's was based on three features: the mean duration of the hibernation periods during the midwinter plateau, the existence of the initial and terminal phases with the changing length of the hibernation periods, and the differences between the sexes. The T A of 4 °C was the optimal T A for long-term hibernation. The difference between 4 °C and other T A's was greater in males. The T A's of 0 and 9 °C were near the lower and higher T A limits for longterm hibernation. Signs of the existence of a circannual rhythm were detected in the males toward the end of the hibernation season.

Studies on the epidemiology of Uncinaria stenocephala infections in British greyhounds: development and persistence of larvae on herbage

Faeces carrying the eggs of Uncinaria stenocephala were placed on plots of grass in the south east of England at monthly intervals. Larval development and translation occurred in as little as one week at the height of summer but took up to five months in winter. Rapid development was observed as late as November and a few larvae managed to reach the third infective stage even in midwinter. Over wintered larvae persisted into May or June to be replaced by a new generation of larvae at about the same time.

The Agriculture of Seasonal Labor Migration Farms in Obanazawa

In Japan, the character of the seasonal labor migration under the high economic growth since 1960 differs from that before it. The former was caused by the factors belonging to demands rather than supplies. Its analysis from the standpoint of the supplies must be begun with the discussion of relations between the seasonal labor migration and agriculture types of farms at first. As an object of the above discussion Obanazawa city, Yamagata Prefecture, was chosen.About 95% of seasonal labor migration households are farm households. Their laboring period is generally six months in winter, from mid-November to mid -April. In Obanazawa city, the percentage of the seasonal labor migration farms increased from 3.6% in 1960 through 54.3% in 1970 to its maximum of 59.4% in 1973. Very much of them engaged in industries such as construction and manufacturing. The number has decreased, however, as to whole seasonal labor migrants and as to those who engaged in manufacturing since 1974. It must have been one of the results of the economic depression in Japan after the “Oil Shock” at the end of 1973.Some interviews have been given in order to clarify the relation between the seasonal labor migration and the farming in three communtites, Shôgon, Takahashi, and Iwayazawa in Obanazawa.The results obtained are as follows:1) The seasonal labor migration farms are found much among the farms of larger size. In contrast, the smaller are almost those “engaged in constant work” and “operating side business”.2) Among seasonal labor migration farms, some introduce and intensify summer crops as leaf tobacco and water melon, attempting an expansion of their farming. Much of them are seen in Shôgon. In leaf tobacco culture, two works, rearing seedlings and shipment, are in conflict with seasonal labor migration in season. Farmers cultivating leaf tobacco conquer this problem in terms of co-operating and of alternating varieties, and aim at the expansion of their farming.3) There are others who gradually reduce and cut off lower revenue parts of their farming such as seri-culture, intending for the rice monoculture. Much of them work as manual laborer in the slack season for farmers in summer to get cash income. They are seen mainly in Takahashi and Iwayazawa.4) There are antipodal trends of the farming among them. The point of sameness, however, is that they adapt their farming to the seasonal labor migration, being premised on the latter.